Search

• Pollination is essential for both fruit production as well as genetic variations. • Dichogamous nature of walnut is hindering pollination, fruit set and breeding. • Inter-specific hybrids offer considerable variations and genetic diversity. • Better understanding of pollination mechanisms can reduce PFA in walnuts. Pollination promotes both fruit production as well as genetic variations in fruit crops. Walnut belongs to the deciduous, monoecious, anemophilous and self-compatible fruit tree. Regardless of self-compatibility, due to dichogamous nature of crop it is hindering pollination, fruit set and breeding in walnut. Pollination mechanisms in walnut are not completely understood, and this unusually complex pollination behavior necessitates that we improve our mechanistic understanding of cytology, flower and pollen morphology, pollen collection, storage and germination and pollination process in walnut. A deeper understanding of pollination mechanisms is vital for fruit production as well as to reduce pistillate flower abortion (PFA) and to speed up future walnut breeding and varietal improvement by enhancing genetic diversity and developing hybrid verities targeted for having desirable traits like lateral bearing, precocity, batter fruit quality, high productivity, earlier harvest and resistance to late-spring frost, cherry leaf roll virus (CLRV), blight and pistillate flower abortion. A comprehensive grasp of walnut pollination mechanisms enables experts to offer more effective technical guidance to walnut growers. This article presents recent advancements in our understanding, consolidating pertinent and up-to-date information on walnut pollination mechanisms into a single resource for the first time. It serves as a valuable reference for researchers engaged in horticultural research, particularly in the domains of pollination, fruit production, and walnut tree breeding. [ABSTRACT FROM AUTHOR]

• By shortening long juvenile period of fruit trees plant breeders are able to improve apple fruit production. • The goal of this research was to identify the candidate loci for apple flowering using the cDNA-RAPD technique. • ALL3-Ah1 (815-820 bp), ALL11-Ah1 (740-750 bp), ALL40-Ah7 (885-900 bp), ALL41-Ah7 (800 bp), and ALL45-Ah8 (790-800 bp) could be considered as the primers linked to the flowering control genes. • ALL44-Ah8 (700-710 bp) could be considered as the linked primer with the genes controlling the vegetative bud situation. • The above-mentioned primers could be applied to the selection of the flower or vegetative situations for apple trees breeding or may even be applied to other trees with similar loci. • They could further be sequenced and used for gene transformation for flowering induction and shortening the juvenile period in apple trees. The juvenile period in trees may keep breeders from the early achievement of successive generations in fruit tree breeding. Shortening this period could lead the plant breeders to improve fruit production faster. The objective of the current research was to identify the candidate loci or primers for apple flower and vegetative (leaf) buds using the cDNA-RAPD technique. Leaf and flower buds were collected from Red and Golden Delicious apples. The synthesized cDNAs were amplified using the cDNA-RAPD based gene expression technique by 10 RAPD primers. All the primers were polymorphic, with an average of 6.2 bands and an average PIC value of 0.162. The highest number of polymorphic bands belonged to the Ah1 primer (11 bands). Marker index (MI) was obtained between 0.702 for Ah6 primer, and 1.32 for Ah1, implying a higher efficiency of the Ah1 primer in determining polymorphisms. Ah3 and Ah4 were more efficient in this respect than the other examined primers. Binary logistic and cluster analyses results showed that the ALL3-Ah1 (815-820 bp), ALL11-Ah1 (740-750 bp), ALL40-Ah7 (885-900 bp), ALL41-Ah7 (800 bp), and ALL45-Ah8 (790-800 bp) bands (alleles) have a significant association with the flower buds, and the ALL44-Ah8 (700-710 bop) allele with the vegetative buds. The identified alleles could be further sequenced and utilized to induce flowering in apple trees. They could be considered as the primers linked to the flowering or vegetative control loci. These primers may serve as selection criteria in the molecular breeding of flowering or vegetative states in apple. It provides a foundation for future studies toward the determination of the functional importance of these candidate loci for shortening the juvenile period of the apple trees. They can be utilized for genetic transformation to induce flowering and shorten the juvenile period in apples and similar trees. [ABSTRACT FROM AUTHOR]

To study the molecular characteristics, phylogenetic evolution, and gene functions of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) genes in Paulownia fortunei , a whole genome sequence analysis was carried out, and a total of 23 PfSPL genes were identified. Tandem duplication and fragment replication were the main patterns of gene expansion in the PfSPL family. Phylogenetic analysis showed that the 23 identified PfSPLs formed seven subgroups, and the structures of the proteins in the same subgroup were similar. Functional analysis indicated that PfSPL11 may regulate flowering, PfSPL5 was involved in gibberellin signaling, PfSPL1 / 4 / 23 regulated branching, and PfSPL9 / 16 / 18 were related to pathogen resistance. Yeast one hybrid technology confirmed that PfSPL4 and PfSP23 can bind to the promoter of PfTCPa. The transcriptome analysis indicated that PfSPL10 was sensitive to both drought and salt stress. Ten PfSPLs that responded to phytoplasma infection were identified. Molecular docking showed that PfSPL10 and PfSPL 4/5/9/10/11/13 formed active pockets in the conserved SBP domain that could bind methyl methane sulfonate (MMS) and rifampicin (Rif) through stable hydrogen bonds, respectively. This study provides a basis for further studies on the functions of the PfSPL transcription factor family, and for genetic improvement and breeding of trees resistant to Pa WB disease. [ABSTRACT FROM AUTHOR]

Genomic and phenomic prediction (GP and PP, respectively) are innovative methods that allow plant breeders to increase the productivity of crops. Traditional methods for conducting GP and PP typically rely on linear regression models with predefined assumptions and cannot capture the complex relationships between genotypes and phenotypes. Deep learning models are focused on nonlinear algorithms that can potentially capture complex nonadditive effects, including dominance and epistasis, presenting an opportunity for improving GP and PP accuracy. In this study, the predictions of deep learning models (convolutional neural networks: CNN and multilayer perceptron: MLP) were compared those of Bayesian alphabet models (BayesA, BayesB, BayesCπ, Bayesian lasso, and Bayesian ridge regression) using both single nucleotide polymorphisms (for GP) and spectral information (for PP) datasets for eucalyptus trees adapted to arid environments. The deep learning models consistently outperformed the Bayesian models in predicting most traits, with accuracy estimates ranging from 0.13 to 0.80 for the MLP, 0.16–0.82 for the CNN, and 0.08–0.66 for the Bayesian models. Additionally, spectral information significantly enhanced the accuracy in predicting 50 % of the traits, mainly when applied to deep learning models, demonstrating the potential of high-throughput phenotyping techniques combined with deep learning models in the prediction of important agronomic traits. Thus, deep learning models and spectral data should be incorporated as a strategy for tree breeding programs. • Deep Learning models showed superior predictive abilities than Bayesian models. • Spectral information significantly enhanced prediction accuracy. • Leaf spectral dataset had the highest accuracies in most of the traits [ABSTRACT FROM AUTHOR]

It is known that laccase genes are involved in lignin synthesis. Eucalyptus is an important timber species; functional studies of specific laccase members and their upstream regulatory factors in Eucalyptus are incomplete, and the mechanism of lignin content variation in polyploid plants remains unclear. Therefore, in this study, we investigated the function of EuLAC17 by overexpressing it in tobaccos and the result showed the lignin content in transgenic tobacco increased significantly. Further, yeast one hybrid sequencing was used to identify a series of potential regulatory factors of EuLAC17 , among which EuMYB308 showed the most significant correlation with EuLAC17. Yeast one hybrid, dual-luciferase reporter gene assay and electrophoretic mobility shift assay jointly verified that EuMYB308 could directly target the EuLAC17 promoter and repress its expression. In addition, overexpression of EuMYB308 resulted in significant reductions in plant growth, xylem cell lumen area, cell wall thickness and lignin content. Transcriptome sequencing showed that lignin biosynthesis genes including laccase genes were significantly differential expression in transgenic plants compared with wild-type plants. In triploid Eucalyptus urophylla , the expression of EuMYB308 was significantly upregulated, which may enhance the inhibition of EuLAC17 and thus reduce its expression level in triploid, which is one possible reason for the reduced lignin content in triploid E. urophylla. This study provides important insights into transcriptional regulation of lignin biosynthesis in Eucalyptus , and also contributes to revealing the genetic mechanism of lignin content variation in polyploid plants, which are of great significance for promoting the improvement of wood quality in forest trees and polyploid breeding. • EuMYB308 has an important influence on the regulation of lignin content in Eucalyptus urophylla. • A mode of negative regulation of lignin content by EuMYB308 targeting EuLAC17 was identified. • Differential expression of EuMYB308 may be an important reason for the reduced lignin content in triploid Eucalyptus. [ABSTRACT FROM AUTHOR]

Phenolic compounds (PC) are important secondary metabolites in plants, playing a crucial role in plant defense mechanisms against pathogens and other plants. Monitoring PC levels is important for understanding tree stress and implementing effective breeding programs. However, traditional methods for monitoring PC are time-consuming, prone to altering the phenolic composition, and mostly applicable only on a small scale. In this study, we evaluated the performance of Unoccupied Aerial Vehicles (UAV) multispectral imaging in estimating the canopy phenolic content in slash pine over an 11-month period in 2021 and a seven-month period in 2022. Three machine learning models including Partial least squares regression (PLSR), Random forest (RF) and Support Vector Machine (SVM) were compared to determine the optimal predictive model for canopy PC. The RF model provided the best predictive results, with R2 values of 0.82 for the validation set and 0.94 for the calibration set. Additionally, the study assesses the heritable variation in canopy PC over time, with the monthly heritability (h 2 ) of PC ranging from 0 to 0.26 in 2021 and from 0 to 0.35 in 2022; The highest h 2 levels were observed in July and September 2021and July 2022. The findings demonstrate significant genetic control over the variation of PC. Furthermore, we observed higher breeding values and genetic gains in July and November, which further supports the strong correlation between PC and environmental factors such as temperature and light intensity. To the best of our knowledge, this is the first study to employ time-series UAV multispectral imaging to predict secondary metabolites in pine trees and estimate their genetic variation over time. As a proof of concept, these findings provide more reliable information for tree breeding programs, ultimately enhancing their overall performance. • UAV Innovation: First-time use of UAV multispectral imaging for phenolics in slash pine. • ML Models: Random Forest model showed highest accuracy in predicting canopy phenolics. • Genetic Insights: Detailed analysis of heritable variation in canopy phenolics over time. • Seasonal Analysis: Conducted comprehensive statistical analysis of phenolic content variations. [ABSTRACT FROM AUTHOR]

Tree peony is an important plant that integrates ornamental, oil, and medicinal use. However, drought stress seriously restricts the development of the tree peony industry and the improvement of its economic value. In this study, Paeonia ostii 'Fengdan' was used as the experimental material, their biological functions were verified by bioinformatics analysis, dual-luciferase reporter assay, overexpression transformation, and momentary transformation. The results of the degradation group showed that PomiR396g-5p cut the target gene PoACO1 at 1082 bp, and the double luciferase report test showed that PomiR396g-5p reduced the fluorescence activity of the target gene PoACO1 , and there was a targeted cutting relationship between PomiR396g-5p and PoACO1. PomiR396g-5p promoter contained a variety of cis -acting elements related to abiotic stress, and the PoACO1 protein was an intracellular hydrophilic protein, did not have a transmembrane structure, and was mainly located in the nucleus and cytoplasm. PomiR396g-5p transgenic plants had enhanced drought resistance, improved the activities of POD, SOD, CAT, and other antioxidant enzymes, and reduced the accumulation of ROS. The expression of PoACO1 in PomiR396g-5p transgenic plants was inhibited. The rate and amplitude of leaf length, width, and fresh weight decrease in the miRNAs group were lower than those in the control group and target genome. Whereas instantaneous silencing of tree peony leaves showed the opposite trend to transgenic plants and homologous instantaneous overexpression. The symptoms of acute leaf atrophy and water loss were observed in the PomiR396g-5p at 9–12 h, and the decrease rates of fresh weight, leaf length, and leaf width were significantly higher than those in the target genome and control group. In conclusion, PomiR396g-5p acted as a positive regulator of tree peony in response to drought stress and improved drought resistance by regulating the target gene PoACO1 to inhibit its expression and regulation of ROS levels in plants. Meanwhile, there was a negative regulatory relationship between PomiR396g-5p and the target gene PoACO1.Our study provides a theoretical basis and technical support for the research on drought resistance molecular breeding of tree peony. • PomiR396g-5p cut the target gene PoACO1 at 1082 bp, and PomiR396g-5p reduced the fluorescence activity of PoACO1. • PomiR396g-5p promoter contained a variety of cis -acting elements related to abiotic stress. • PomiR396g-5p transgenic plants had enhanced drought resistance. The PoACO1 in PomiR396g-5p transgenic plants was inhibited. • PomiR396g-5p acted as positive regulatory factors in response to drought stress of tree peony. [ABSTRACT FROM AUTHOR]

Due to the extended generation cycle of trees, the breeding process for forest trees tends to be time-consuming. Genetic engineering has emerged as a viable approach to expedite the genetic breeding of forest trees. However, current genetic engineering techniques employed in forest trees often utilize continuous expression promoters such as CaMV 35S, which may result in unintended consequences by introducing genes into non-target tissues. Therefore, it is imperative to develop specific promoters for forest trees to facilitate targeted and precise design and breeding. In this study, we utilized single-cell RNA-Seq data and co-expression network analysis during wood formation to identify three vascular tissue-specific genes in poplar, PP2-A10 , PXY , and VNS07 , which are expressed in the phloem, cambium/expanding xylem, and mature xylem, respectively. Subsequently, we cloned the promoters of these three genes from '84K' poplar and constructed them into a vector containing the eyGFPuv visual selection marker, along with the 35S mini enhancer to drive GUS gene expression. Transgenic poplars expressing the Pro PagPP2-A10 ::GUS, Pro PagPXY ::GUS, and Pro PagVNS07 ::GUS constructs were obtained. To further elucidate the tissue specificity of these promoters, we employed qPCR, histochemical staining, and GUS enzyme activity. Our findings not only establish a solid foundation for the future utilization of these promoters to precisely express of specific functional genes in stems but also provide a novel perspective for the modular breeding of forest trees. ● Three vascular tissue specific genes were identified in poplar. ● eyGFPuv visual marker to observe easier and faster for select transgenic plants. ● Develop vascular-specific promoters to facilitate precise breeding for trees. [ABSTRACT FROM AUTHOR]

Great interests in silver birch (Betula pendula) forests have increased in an attempt to handle biodiversity and resilient forest management with more broad-leaved forests. However, up-to-date silver birch growth and yield models are still needed to predict the stand development in the future and support operational forest management and planning. The objectives of this study were to develop site index and stand characteristic models for silver birch plantations. Data for modelling were from the thinning and spacing experiments and tree breeding trials on silver birch plantations in southern and central Finland. The dominant height and site index (SI) models were fitted using the nonlinear mixed effect regression approach based on the Chapman-Richards function with the genetic effect from improved seedlings. The modelling result indicated a logical growth performance over age and higher dominant height with genetically improved seedlings. The stand characteristic models for unimproved seedlings were developed using multivariate mixed-effects modelling approach. The targeted, response variables were the basal area-weighted mean height (HW, m), the basal area-weighted mean diameter (DW, cm) and stand basal area (G, m2 ha−1) of silver birch. Stand biological age (AGE, year), SI estimated based on the model of the current study with the base age of 50 years, and the number of silver birch trees (N, trees ha−1) were all commonly applied as highly significant predictor variables for all of HW, DW, and G models. In addition to these predictors, thinning variables, comprised of the time since last thinning in year and the thinning intensity based on G, were highly significant in the DW and G models with logical behavior. Recent thinning affected negatively at first because trees in thinned stands were slimmer than those in unthinned stands that have grown from the early stage at the same level of N with thinned stands. After 13 years since last thinning, the effect turned positive indicating that the increments were expedited with thinning. Lastly, site type classified as either former agricultural land or forest site was included in the DW and G models. Consequently, all the models developed in this study were evaluated as practicable with easy-to-use predictors and desirable accuracy. • The dominant height and site index models were fitted well with genetic effect using the Chapman-Richards function. • Mean height and diameter and stand basal area were modelled using multivariate regression. • Age, site index, and stem number were the commonly-applied, driving predictors in stand characteristic models. • Thinning variables were highly significant in the models of mean diameter and stand basal area. • Simulations demonstrated model application, performance, and validity adequately. [ABSTRACT FROM AUTHOR]

Canopy temperature and new shoot counts are pivotal traits for evaluating the adaptability and productivity of slash pine (Pinus elliottii Engelm.). Traditional methods for assessing these traits are labor-intensive and lack the required accuracy. Despite their ecological and economic importance, the genetic and molecular underpinnings of these traits remain largely unexplored. In this study, we utilized UAV remote sensing technology for conducting high-throughput phenotyping of canopy temperature and new shoot counts and performed a Genome-Wide Association Study (GWAS) to identify key candidate genes associated with these traits. Our Manhattan plot analysis revealed intriguing patterns. The GWAS analysis of both July and August identified the same four key candidate genes for new shoot counts including scaffold119881_56626, scaffold119881_56642, scaffold96999_96025, and scaffold7133_48553 respectively. However, for canopy temperature, no key candidate genes were identified in the overall monthly analysis. Interestingly, diurnal variations in canopy temperature influenced the identification of key genes. While no key genes were identified during the afternoon and evening, two were found in the morning: scaffold33143_278946 and super3157_662643. Our UAV-based approach proved to be highly accurate and portable, with significant heritability estimates for both traits. This study represents the first GWAS analysis on these traits and underscores the importance of integrating high-throughput phenotyping and genotyping technologies for advancing forest genetic improvement programs, particularly in the selection of key candidate genes influenced by diurnal and monthly variations. [Display omitted] • UAV remote sensing enables Pinus elliottii phenotyping. • GWAS links genetic loci to tree adaptability, productivity. • Enhances accuracy beyond conventional trait assessment. [ABSTRACT FROM AUTHOR]

The assessment of plant performance and the accuracy of genetic selection can be significantly affected by genetic competition among individuals. In addition to genetic causes, competition is influenced by external factors such as environment and age. This research uses multi-location multi-age Eucalyptus dunii trials to answer four questions: i) Are there major changes when competition effects (both genetic and residual) are estimated in single-age and multi-age models? ii) What are the implications of considering competition effects on the early selection of eucalypt clones? iii) What are the impacts of considering the reliability of direct (DGE) and indirect genotypic effects (IGE) as a weight in a selection index?, and iv) Which clones hold the potential to form highly productive clonal plantations in Southern Brazil when deployed together as clonal composites? The dataset contained three trials established in different locations in Southern Brazil, where growth traits were measured at 3.5 and 7 years. We fitted single-age and multi-age spatial competition models for each trial. The multi-age spatial competition model was a valuable tool for selecting superior eucalypt clones. Neglecting the IGEs led to changes in clone ranking, reducing the effectiveness of early selection. Additionally, a selection index where DGEs and IGEs are weighted by their reliability was proposed. Therefore, our study contributes to understanding the magnitude of IGE's impact on the daily practice of eucalypt breeding, such as early selection and multi-age analyses, and proposes selection strategies that consider the quantity and quality of information provided by the models for each individual. • Indirect genotypic effects can impact the ranking and mislead the early selection. • Multi-age spatial competition model yielded higher accuracy than single-age models. • The reliability of direct and indirect genotypic effects should be considered as a weight in a selection index. • The trade-off between direct and indirect genotypic effects can be used to recommend genotypes to Southern Brazil. [ABSTRACT FROM AUTHOR]

The linkage in new and creative ways of existing plant breeding methods responsive to different global trends and values provides a 'systems approach' to address a broad set of global production challenges more effectively. Here, we illustrate such an approach through its application to trees, chosen because of their extensive diversity in features, uses, users, production contexts, and domestication pathways. We coin the resulting strategy 'tree diversity breeding' and consider it with reference to trends and values related to participation, environment, biotechnology, and markets as examples. Features of the approach for trees are applicable to plant breeding more widely, as we seek to address complex problems through strategic biodiversity use. A 'systems approach' to plant breeding is increasingly recognised as required to address broad global challenges including the transgression of multiple planetary boundaries. In this opinion piece we describe a systems approach to plant breeding that is based on advancing novel and creative linkages between existing breeding methods that are oriented to multiple global trends and values. We illustrate our concept for how biodiversity can be mobilised strategically to address pressing global needs by considering the case study of tree genetic improvement. We choose 'tree diversity breeding' as our example based on the increasingly crucial roles of trees in supporting continued human development and the environment, and because of trees' enormous diversity that provides significant opportunities for a systems approach to genetic improvement. [ABSTRACT FROM AUTHOR]

Branch architecture plays an important role in forest physical and ecological processes, greatly affecting forest spatial structure and the accumulation, production and distribution of organic carbon. Very few studies have quantified the branch architecture of large-scale forest plots, due to the lack of high-resolution large-scale three-dimensional data. The emergence of unmanned aerial vehicle-light detecting and ranging (UAV-LiDAR) provides great potential to overcome this limitation. However, due to insufficient quality of UAV-LiDAR data for branch reconstruction, existing algorithms remain tremendously challenging. We propose an effective branch reconstruction algorithm for UAV-LiDAR data to quantify branch architecture. First, individual branches are extracted using a region growth method that is guided by the branch growth direction and local smoothness constraint. Second, incorrect branches are eliminated based on three pieces of branch features, i.e., specific angles between branches at the same whorl, specific height differences between branches at different whorls, and the growth pattern of branches from the stem outward, reaching maximum distances at tips. Finally, branches are reconstructed using polynomial fitting, and branch architecture parameters are extracted based on branch models. The proposed algorithm simplifies branch reconstruction by skipping the separation of photosynthetic and non-photosynthetic components. It also adapts well to UAV-LiDAR point clouds, generating more realistic reconstructions. The algorithm successfully identified non-photosynthetic components in experiments involving 240 trees, including Scots pine, Norway spruce, and Radiata pine. The average overall accuracy for these three species was 0.88, 0.76, and 0.74, respectively. The proposed algorithm was tested for branch reconstruction using UAV-LiDAR data from a two-hectare Larix principis-rupprechtii plot. The accuracy of branch identification and parameter extraction accuracy were evaluated branch by branch based on the individual branches manually identified in terrestrial laser scanning data. Results showed the F- score of branch and stem identification was 0.58 and 1. The relative RMSE of branch length and angle was 36.87% and 18.3%, and ones of stem length and diameter were 1.46% and 6.16%. The proposed algorithm outperformed the well-known reconstruction algorithms, including TreeQSM, AdTree and Laplacian-based algorithms. • A branch reconstruction algorithm is proposed for UAV-LiDAR data. • It simultaneously generates wood-leaf separation results and branch models. • Branch parameters are extracted and quantitatively assessed individually. • Algorithm creates more realistic branch models especially for visually tough ones. • It advances studies in LAI estimation, tree breeding, ecological insights, etc. [ABSTRACT FROM AUTHOR]

Polyploidy, or genome doubling, has occurred repeatedly through plant evolution. While polyploid plants are used extensively in agriculture and horticulture, they have so far found limited use in forestry. Here we review the potentials of polyploid trees under climate change, and investigate if there is support for increased use. We find that polyploid trees like other plants have consistent increases in cell sizes compared to diploids, and that leaf-area based rates of photosynthesis tend to increase with increasing levels of ploidy. While no particular trend could be discerned in terms of biomass between trees of different ploidy levels, physiology is affected by polyploidization and several studies point towards a high potential for polyploid trees to adapt to drought stress. The ploidy level of most tree species is unknown, and analysis of geographical patterns in frequencies of polyploid trees are inconclusive. Artificial polyploid trees are often created by colchicine and in a few cases these have been successfully applied in forestry, but the effects of induced polyploidization in many economically important tree species remains untested. Polyploids would also be increasingly useful in tree breeding programs, to create synthetic hybrids or sterile triploids that could control unwanted spreading of germplasm in nature. In conclusion, this review suggests that polyploid trees may be superior under climate change in some cases, but that the potential of polyploids is not yet fully known and should be evaluated on a case-to-case basis for different tree species. [Display omitted] • We reviewed contemporary literature on polyploid trees. • Although polyploidy is common, the ploidy level of many tree species is unknown. • Polyploidy alters anatomy, physiology and growth of trees, making some more stress tolerant. • Increased use of polyploid trees could be advantageous under climate change conditions. • Polyploids should be further investigated for their potential to increase productivity in forestry. [ABSTRACT FROM AUTHOR]

An important problem in the breeding of livestock, crops, and forest trees is the optimum selection of genotypes that maximize genetic gain. The key constraint in the optimal selection is a convex quadratic constraint that ensures genetic diversity, so that optimal selection can be cast as a second-order cone programming (SOCP) problem. Yamashita et al. (2015) exploit the structural sparsity of the quadratic constraints and reduce the computation time drastically while attaining the same optimal solution. This paper is concerned with a special case of equal deployment (ED), in which we solve the optimal selection problem with the constraint that contribution of genotypes must either be a fixed size or zero. This involves a form of combinatorial optimization, and the ED problem can be described as a mixed-integer SOCP problem. In this paper, we discuss conic relaxation approaches for the ED problem based on LP (linear programming), SOCP, and SDP (semidefinite programming). We then propose a steepest-ascent method that combines the solution obtained from the conic relaxation with a concept from discrete convex optimization, in order to acquire an approximate solution for the ED problem in a practical time. From numerical tests, we observed that among the LP, SOCP, and SDP relaxation problems, SOCP gave a suitable solution from the viewpoint of the optimality and computation time. The steepest-ascent method starting from the SOCP solution provides high-quality solutions much faster than other existing methods that have been widely used for optimal selection. [ABSTRACT FROM AUTHOR]

The study aims to analyse the stability of the narrow crowned Norway spruce (pendula form) compared to the normal spruce form (pyramidalis form) and the hybrids of the two forms, in 5 field trials (Comandău, Lepşa 1&2, Ilva Mică and Voineasa) located in the Romanian Carpathians. Trees height (Th), breast height diameter (Dbh), height growth of the last year, crown diameter (Cd), number of branches per whorl (Nbw) and dominant branch diameter (Dbd) traits were measured and survival rate (Sr) was determined, at 20 years old. Also, branches finesse (Bf), trees volume (Tv) and trees slenderness (Ts) were calculated. In order to compare the wood density (Cwd) there were collected cores. In all trials ANOVA revealed significant (p < 0.05) differences between the two forms of spruce and the hybrids (mainly between those that have a different crown form mother), especially for the stability and quality traits. Factorial ANOVA revealed a high influence (p < 0.001) of the locality and also a significant influence (p < 0.05) of the locality × spruce form interaction. The factor "form" was significant for some traits involved in Norway spruce stability (Ts, Cd, Nbw). The pendula trees present higher values for Sr, Dbh and Tv, and lower values for Ts, Cd, Nbw, Dbd and Bf, compared to pyramidalis spruce form, which showed a higher stability. Heritability was in generally low (h2 < 0.4), with exceptions of Ts which presents a medium rate of heritage. For the same trait, different heritability was registered in different environmental conditions. The Cwd was higher only with 2% for the pendula form in Lepşa trial, while in Comandău trial the pyramidalis registered a higher value (7%). In the new breeding programme, the selection strategy may be pursued with the pendula trees selection based on Ts and branches traits. Unlabelled Image • The narrow crown Norway spruce ideotype presents superior stability compared to normal crown form. • 42% of the consanguineous trees survived and most of them are dominated and will disappear in the next years • Breeding strategy could begin with the selection of pendula after trees slenderness, trait with the highest heritability [ABSTRACT FROM AUTHOR]

• Genetic differentiation is low between introduced and Australian populations. • Mating in the introduced populations occurred mainly by outcrossing. • Mating was not random due to the genetic drift and self-fertilization. • Progenies present inbreeding and are mixtures of different levels of relatedness. • Nine Brazilian populations show correct attribution to their reference population. To better understand the genetic variability among and within Eucalyptus grandis populations introduced in Brazil, we use microsatellite loci to investigate the mating system, genetic structure, and Australian origins of several introduced provenances. Our sample includes 981 trees from ten Brazilian populations and 254 trees from 18 Australian populations. Significant higher observed heterozygosity (H o) and significant lower fixation index (F) was detected in grouped Brazilian provenance (H o = 0.753, F = 0.140) than in Australian samples (H o = 0.680, F = 0.220). However, Brazilian samples presented significantly lower genetic differentiation (G ST ′) among populations (0.541) than Australian populations (0.838) indicating that the overall genetic diversity captured in the Brazilian collection is low due to the limited number of populations represented. All sampled Brazilian populations showed 100% correct expectation of attribution to their reference population, showing consistency with historical information. A lower fixation index (F) was detected in Brazilian seed trees (−0.101) than their offspring (0.140), suggesting selection against inbred individuals between seedling and adult stages. The outcrossing rate (t m) was high (0.994) with low variability among populations (0.921–0.969). However, some mating occurred between related trees (t m - t s = 0.149) and were correlated (r p (m) = 0.113), indicating that some offspring are inbred and families are composed of different levels of relatedness. The coancestry (Θ = 0.141) was higher and the effective size within families (N e = 3.09) lower than that expected for half-sib families (Θ = 0.125; N e = 4). Brazilian E. grandis populations offer the possibility to develop new breeding populations with high genetic variability due to their differing origins combined with individual selection. [ABSTRACT FROM AUTHOR]

• Long-term trials with various stand densities and genetic improvement were analysed. • A strong relationship between Total Value (NZ$/ha) and stand density was identified. • The relationship was more site specific for Relative Value (NZ$/m3). • Approximately 60 • There were significant interactions between seedlot and site, and between site and stand density. Intensively managed forests are expected to play an increasingly important role in meeting future global demand for wood products. To meet this challenge, a key focus will be on lifting yields from these forests along with economic returns. In this study, we used data from a long-term series of trials that were established in radiata pine (Pinus radiata D. Don) to examine the effect that stand density, deployment of genetically-improved seedlots, and site have on economic returns. This dataset comprised end-of-rotation assessments of eight installations of a trial series in New Zealand that spanned a wide range of site productivity. Each installation typically contained four seedlots with differing levels of genetic improvement growing at three levels of stand density. Mixed effects models were used to examine the effects of stand density, site, seedlot genetic rating, and their interactions on Total Value (NZ$ ha−1) and Relative Value (NZ$ m−3). There was a strong positive relationship between stand density and Total Value, but there was generally no significant relationship between stand density and Relative Value. Of the variation in Total Value not explained by the fixed effect of stand density, approximately 60% was due to differences among trial installations (i.e. site) and 5–7% was due to seedlot genetic worth. There were significant first order interactions between seedlot and site, and between site and stand density. Seedlot genetic worth was able to explain a higher proportion of the variation in Relative Value (between 10 and 18% depending on the genetic trait under consideration). The genetic worth of a seedlot in terms of stem straightness rating was able to explain the greatest proportion of variation in Relative Value. These results highlight the importance of the choice of location and stand density management have on the economic returns from intensively-managed forests. While seedlot genetic rating has a smaller effect on economic returns, improvements in traits such as stem straightness and branch characteristics also make an important contribution. As silvicultural practices move towards higher stand densities, and the next generation of genetically improved trees are deployed, a more precise understanding of the interactions of site, silviculture and genetics will be needed. New ways of testing and modelling these interactions will be required but will ensure the delivery of a more informed approach to forest management. [ABSTRACT FROM AUTHOR]

• First genomic selection study in forest trees that compare GBLUP and ssGBLUP approaches. • ssGBLUP takes into account genotyped and non-genotyped trees simultaneously in the same evaluation. • ssGBLUP provided higher prediction accuracy and lower bias of breeding values than GBLUP. • ssGBLUP is more relevant for low-heritable traits. Genomic Best Linear Unbiased Prediction (GBLUP) in tree breeding typically only uses information from genotyped trees. However, information from phenotyped but non-genotyped trees can also be highly valuable. The single-step GBLUP approach (ssGBLUP) allows genomic prediction to take into account both genotyped and non-genotyped trees simultaneously in a single evaluation. In this study, we investigated the advantage, in terms of breeding value accuracy and bias, of including phenotypic observation from non-genotyped trees in a standard tree GBLUP evaluation. We compared the efficiency of the conventional pedigree-based (ABLUP), GBLUP and ssGBLUP approaches to evaluate eight growth and wood quality traits in a Eucalyptus hybrid population, genotyped with 33,398 single nucleotide polymorphisms (SNPs) using the EucHIP60k. Theoretical accuracies, predictive ability and bias were calculated by ten-fold cross validation on all traits. The use of additional phenotypic information from non-genotyped trees by means of ssGBLUP provided higher predictive ability (from 37% to 75%) and lower prediction bias (from 21% to 73%) for the genetic component of non-phenotyped but genotyped trees when compared to GBLUP. The increase (decrease) in the prediction accuracy (bias) became stronger as trait heritability decreased. We concluded that ssGBLUP is a promising breeding tool to improve accuracies and bias over classical GBLUP for genomic evaluation in Eucalyptus breeding practice. [ABSTRACT FROM AUTHOR]

Highlights • Marker efficiency in selecting grape seedless varieties depends on genetic background. • Frequencies of false positives and negatives were different for the best markers. • Validation of seedlessness-related markers is necessary for each parental combination. Abstract One of the leading goals in novel breeding programs on table grapevine is the set-up of novel seedless varieties. Seedlessness has a strong impact on consumers' choices representing an important added economic value compared to traditional cultivars. Breeding in tree crops greatly benefits from the use of molecular markers associated to a trait of interest. Nevertheless, one of the main limitations hampering marker assisted breeding is the lack of marker validation on multiple genetic backgrounds. To this extent, we evaluated the efficiency of four markers linked to seedlessness on 97 F 1 genotypes derived from 16 cross combinations obtained through in vitro embryo rescue. Our results confirmed that the four markers were associated to seedlessness even though all, to a different extent, showed marker-trait inconsistencies. Marker efficiency was then tested on the different genetic backgrounds composing the entire germplasm providing a more acurate overview of the marker performances when the genetic background changes. Overall, the most efficient markers were VMC7f2 and p3_VvAGL11 even though their effectiveness changed remarkably from one genetic background to another. This work reports a marker validation assay on a germplasm created to encompass the actual allelic variability employed by breeders. The results could represent a valuable tool to guide the choice of the best markers to assist selection, a choice that should be based, more than on the absolute efficiency of the marker, on a careful evaluation of its performance on the genetic backgrounds in analysis. [ABSTRACT FROM AUTHOR]

Biotic and abiotic stresses have been making it difficult to maintain the rates of genetic gains in forest tree breeding. Planting a mixture of genotypes or clonal composites can be an alternative to increase the security of forest plantations. The formation of clonal composites is complex due to inter-genotypic competition and indirect genotypic effects that can affect the efficiency of genetic selection. This study aims to understand how indirect genotypic effects can impact the response to selection and how the stand composition can be used to explore these effects and enhance forest yield. We used two clonal trials of eucalyptus hybrids implanted in a randomized complete block design with 24 replications, containing a single tree per plot evaluated for mean annual increment at 3 and 6 years. We focused on partitioning the genotypic variation into direct and indirect genotypic effects based on competition intensity factors. We identified aggressive, homeostatic, and sensitive clones based on the magnitude of indirect genotypic effects. Considering indirect genotypic effects, for mean annual increment, the total heritability decreased from 0.25 to 0.10 for 3 years and from 0.30 to 0.14 for 6 years, respectively. We proposed a workflow that uses the direct and indirect genotypic effects to predict the mean values for clonal composite combinations and to select the one with the highest yield. Our methodology considered spatial variation and interplot competition that can affect the total heritable estimates and response to selection in forest trials. The clones were classified as aggressive, homeostatic, and sensitive, according to their deviation from the indirect genotypic effects means. Our methodology enabled the extraction of useful information and predict many clonal composites' performance, which can be used in recommending genotypes to be planted in mixtures. • The heritabilities are overestimated by not considering indirect genotypic effects. • The trade-off between direct and indirect genotypic effects must be considered. • A method for predicting high-performance clonal composites was proposed. • Total genotypic values were used to identify high-performance clonal composites. [ABSTRACT FROM AUTHOR]

Main causes of drying degrade in most plantation-grown eucalypt timber are collapse and checking. Appropriate but costly sawing and drying techniques are employed to alleviate these problems. Eucalyptus globoidea is an emerging plantation species. This study investigated the genetic control of collapse and other tree features in an E. globoidea breeding population established at three different sites. Using a 14-mm diameter corer, thousands of E. globoidea trees representing 163 families were sampled, and genetic parameters for heartwood and sapwood collapse, extractive content, and heartwood diameter were estimated. Heartwood collapse was under genetic control with a narrow sense heritability ranging from 0.22 to 0.44. Considering the coefficient of genetic variability of ∼13–23%, heartwood collapse in E. globoidea can be reduced through selection. The significant genetic correlation between sites for heartwood collapse (r g = 0.73–0.83) suggested low genotype by environment (G × E) interaction. In line with the physical causes of collapse, heartwood collapse was positively correlated with extractive content. Extractive content and heartwood diameter are other traits of interest, as E. globoidea is grown for its ground-durable heartwood. The heritability of extractive content ranged from 0.40 to 0.71. Heartwood diameter was shown to be negatively correlated to extractive content. No significant genotype by environment (G × E) interaction was found for extractive content while genotype by environment (G × E) interactions for heartwood and sapwood diameter were small. Finally, 12 families had above-average heartwood diameter, extractive content, and below-average heartwood collapse. In summary, this study has shown that genetic selection for collapse and other wood properties of E. globoidea is feasible. [Display omitted] • Tree breeding is a long-term, permanent solution to remediate wood drying collapse. • Thousands of E. globoidea trees of known genetics were sampled using a 14-mm corer. • Heartwood collapse, heartwood quality and quantity were under genetic control. • Stable rankings across sites suggested low genotype by environment interactions. [ABSTRACT FROM AUTHOR]

• Factor analytic GxE modeling was successful despite an unbalanced dataset. • There is a clear genetic-by-environment interaction signal for each studied traits. • The influence of the environmental variables was most relevant for height. • Understanding genetic-by-environment interaction is key for tree genetic selection. European larch is an ecologically and economically important tree species planted across a wide range of environments. Understanding its response to the rapidly changing climate is essential to developing efficient gene resource management strategies in line with the assisted migration methodology. In this study, we quantified the genotype x environment interaction (GxE) of a larch provenance in a multi-environmental trial analysis using factor analytic (FA) modeling. We analyzed the mean annual height increment (MAI-H), the mean annual diameter increment (MAI-DBH), and wood density (PP). Additionally, we evaluated the effect of several environmental variables on these traits. The genetic correlations between sites varied from −0.53 to 0.99, −0.87 to 0.99, and −0.17 to 0.99 for MAI-H, MAI-DBH, and PP, respectively. This indicates the presence of low to high GxE. The growth traits showed more GxE signal than wood density. Narrow-sense heritability estimates were 0.41, 0.16, and 0.35 for MAI-H, MAI-DBH, and PP, respectively. The FA modeling of order 2 explained 77.4%, 67.9%, and 77.3% of the genetic variance for MAI-H, MAI-DBH, and PP, respectively. For MAI-H, the latent regression plots for the predicted site means indicate a significant positive correlation with the first factor loading. At the individual genotype level, the latent regression plots indicated high levels of GxE, especially for growth traits. Significant and relatively high correlations were found between several EVs and the factor loadings of the FA models, suggesting their possible influence on the genotypic performance across environments. Regarding MAI-H, elevation, averaged monthly mean temperature, precipitation seasonality, and stand age were correlated with the first factor loading. Annual temperature range with both the first and second factor loadings. For MAI-DBH, the mean diurnal range was correlated with the first factor loading. In the case of PP, we found that elevation was correlated with the second factor loading. Overall, this approach successfully modeled the GxE and identified environmental variables likely affecting it. Therefore, we conclude that this methodology is a valuable tool for selecting suitable genotypes adapted to specific environmental conditions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Eucalyptus dunni is a potential species for pulp production. • E. dunni clones have great genetic variance for growth and wood quality traits. • Wood quality traits presented moderate to high heritability values with high selective accuracies. • Growth and wood quality traits present simple genotypes x environments interaction. • Growth and wood quality traits should be considered in tree breeding for pulp production. Abstract The Eucalyptus dunnii Maiden is an outstanding species for growth and wood quality traits. However, important wood quality traits for pulp and paper production are disregarded in tree breeding. Thus, the present study aimed to estimate the genetic parameters of growth and wood quality traits and establish selection criteria to increase pulp production in E. dunnii clones in different environments. The clonal test of E. dunnii was established in a randomized complete block design with a single-tree-plot in three environments. Growth values were obtained from 3.5-year-old trees. Wood quality values were measured by near-infrared spectroscopy. The phenotype index mean annual pulp increment was calculated using the values of mean annual increment, basic wood density, and pulp yield. A mixed linear model via REML/BLUP was used to obtain the genetic parameters and the rank of genotypic values considering several environments. Results revealed genetic variance for wood quality traits in E. dunnii. Klason Lignin presented high broad-sense heritability; basic wood density, pulp yield, mean annual pulp increment, and mean annual volume increment had moderate broad-sense heritability; and total extractives and diameter at breast height showed low broad-sense heritability. All traits presented high to very high selective accuracy. Simple clones x environments interactions were observed for the tested environments. An elite clone of E. dunnii were better than the commercial control clone for annual pulp increment mean. Therefore, the selection based on growth and wood quality traits is essential for pulp and paper sector. [ABSTRACT FROM AUTHOR]

Phenotyping is the accurate and precise physical description of organisms. Accurate and quantitative phenotyping underpins the delivery of benefits from genetic improvement programs in agriculture. In forest trees, phenotyping at an equivalent precision has been impossible because trees and forests are large, long-lived, and highly variable. These facts have restricted the delivery of genetic gains in forestry compared to other agricultural sectors. We describe a landscape-scale phenotyping platform that integrates remote sensing, spatial information systems, and genomics to facilitate the delivery of greater gains enabling forestry to catch up with other sectors. Combining remote sensing at a range of spatial and temporal scales with genomics will ultimately impact on tree breeding globally. Highlights Planted forests with good management records are a useful resource to understand the influence of genetics and the environment on phenotype. Remote sensing is a rapidly evolving group of technologies that will allow us to phenotype individual trees in situ in planted forests. Geographical information systems, data surfaces that describe climate and other abiotic factors, are information-rich. In combination with genetics and genomics, we have presented the concept of the 'phenotyping platform' which involves the phenotyping of whole forests, eventually down to the individual-tree level. The phenotyping platform will allow us to better quantify the key drivers of forest productivity to inform and optimise future breeding and deployment programmes. [ABSTRACT FROM AUTHOR]

Time and resource are the restricting factors for the wider use of chemical information of wood in tree breeding programs. NIR offers an advantage over wet-chemical analysis in these aspects and is starting to be used for tree breeding. This work describes the development of a NIR-based assessment of extractive content in heartwood of E. bosistoana , which does not require milling and conditioning of the samples. This was achieved by applying the signal processing algorithms (external parameter orthogonalisation (EPO) and significance multivariate correlation (sMC)) to spectra obtained from solid wood cores, which were able to correct for moisture content, grain direction and sample form. The accuracy of extractive content predictions was further improved by variable selection, resulting in a root mean square error of 1.27%. Considering the range of extractive content in E. bosistoana heartwood of 1.3 to 15.0%, the developed NIR calibration has the potential to be used in an E. bosistoana breeding program or to assess the special variation in extractive content throughout a stem. [ABSTRACT FROM AUTHOR]

The disease eastern filbert blight (EFB), caused by Anisogramma anomala , severely limits hazelnut ( Corylus avellana ) production in North America. In the 1970s, ‘Gasaway’, a late-flowering pollenizer, was found to be resistant to EFB in the Pacific northwestern U.S., and to transmit its resistance in a predictable Mendelian pattern. Its subsequent use in breeding at Oregon State University led to the release of a number of EFB-resistant cultivars, including Jefferson, Yamhill, Dorris, Wepster, and McDonald, which are now being widely planted across the Willamette Valley of Oregon. However, some cultivars carrying the ‘Gasaway’ R -gene develop EFB in New Jersey. Thus, the utility of this resistance source for breeding plants adapted to the eastern U.S has not been fully evaluated. In this study, we examined the EFB response of seedlings from 31 different full-sib progenies expected to segregate for the ‘Gasaway’ R -gene. Trees were exposed to the disease over at least 5 years and evaluated on a scale of 0 to 5 (0 = resistant, 5 = highly susceptible). In general, we found the number of seedlings free of EFB (class 0) to be less than expected based on prior work in Oregon, but resistant individuals were identified in each progeny, indicating the presence of heritable resistance. When disease response classes 0, 1, and 2 were combined (resistant through highly tolerant) and considered as “resistant”, the expected ratio of resistant to susceptible trees was recovered, signifying that the single dominant allele alone continues to provide a predictable level of at least tolerance. Modifying genes/factors appear to play a role in the final disease response of the individual seedling. It is thus hypothesized that some cultivars selected as resistant in Oregon that develop cankers in New Jersey may lack the necessary modifying genetic factors for full protection in the east. Until these modifying genes are elucidated, long-term field evaluation remains necessary to identify selections that carry the ‘Gasaway’ R -gene and express a high level of resistance to EFB in the eastern U.S. [ABSTRACT FROM AUTHOR]

We investigated the seasonal variations of the molecular and hydrogen isotopic compositions of leaf cuticular n -alkanes (δD alk ) in two subtropical deciduous tree species ( Quercus chenii , Liquidambar formosana ) over a three-year period. Average chain length values of long chain n -alkanes in both species are lower in young leaves than in mature ones. The δD alk values in both tree species show seasonal fluctuations that can be as large as 78‰ in a single year. The seasonal changes in molecular and isotopic compositions suggest that leaf wax n -alkanes in these subtropical deciduous tree species integrate environmental information over a large portion of the annual growth cycle in response to fluctuations in environmental stresses (e.g. storms, droughts). In addition, the changes reveal that seasonal patterns of δD alk can differ between different deciduous species at the same location and among different years. Spring leaves collected in 2014 had more negative δD alk values than those collected in 2015 and 2016, possibly responding to differences in annual precipitation D/H ratios and associated atmospheric circulation. These preliminary results highlight that extended seasonal monitoring of leaf wax δD alk values can improve their application to reconstructing paleohydrological histories. [ABSTRACT FROM AUTHOR]

Wood density, considered a heritable trait, is often associated with drought tolerance and can be a useful trait for tree breeders to select drought-tolerant provenances. Provenance trials are a useful tool to disentangle genetic variation from plasticity of adaptive traits among populations within the same species. If wood density is a strongly heritable trait selected by climatic conditions, we hypothesize that its variation in provenance trials should be shaped by the provenance climatic variables. To test our hypothesis we collected wood density data of provenance trials from the literature. We used thirty publications published between 1966 and 2015 including 25 species (13 angiosperms and 12 gymnosperms). At the intraspecific level, eight species showed significant positive correlations between wood density and drought conditions of the provenance, two species showed the opposite trend and the remaining 15 species showed no correlation with the climatic conditions of the provenances. For the 10 species with wood density strongly linked to the climatic conditions of the provenance, such relationship reflects a strong genetic determinism and a theoretical fitness optimum. For the other 15 species, wood density does not seem to be the main selection target of drought. This information is critical in the frame of breeding programs for selecting provenances more adaptable to different climate change scenarios. [ABSTRACT FROM AUTHOR]

Flowering and shoot branching are significant agricultural traits for apple tree breeding. Cytokinin metabolism and signaling pathways play a crucial role in plant development. However, little is known about cytokinin biosynthetic molecular mechanism and function involved in apple flowering and branching. In this study, an adenylate isopentenyl transferase coding gene MdIPT1 , homologous to AtIPT3/AtIPT5 in Arabidopsis thaliana , was identified. MdIPT1 was highly expressed in apple floral and axillary buds and was dramatically up-regulated during floral induction and axillary bud outgrowth. The promoter of MdIPT1 showed high activity in multiple tissues and responded to different hormone treatments. The MdIPT1 -overexpressing Arabidopsis showed a multi-branching and early-flowering phenotype, with elevated endogenous cytokinin levels and altered expression of genes related to branching and flower formation. Overexpression of MdIPT1 confers the growth vigor of transgenic apple callus on a CKs-deficient medium. Our findings suggest that MdIPT1 is a positive regulator involved in branching and flowering. The data presented herein provide extensive research results on MdIPT1 and will contribute to molecular breeding for new apple varieties. • MdIPT1 is highly expressed in apple floral and axillary buds. • The expression of MdIPT1 responds to the treatment of multiple hormones. • MdIPT1 elevates endogenous cytokinin levels, accelerates floral transition, and increases branching number. [ABSTRACT FROM AUTHOR]

• The feasibility of phenotype measurement with only a smartphone is proved. • The use of multi-camera of smartphone to obtain depth has been confirmed. • Virtual focal solved inconsistency of heterogeneous binocular images in some sorts. • Pinhole camera model provided physical sizes or phenotypes of apple tree. • The phenotyping performance of smartphone is similar to existing researches. Phenotyping plays a significant role in the breeding of apple tree. However, existing researches mainly relied on instruments, such as LiDAR, RGB-D camera or UAV (unmanned aerial vehicle) embedded with depth sensor, etc., which requires additional costs for users and also inconvenient. Therefore, a novel method of smartphone-based heterogeneous binocular vision was developed to fulfill low-cost automated phenotyping for apple tree. In this study, a pair of cameras on multi-camera smartphone was selected to obtain heterogeneous binocular camera. After that, a so-called virtual focal method was developed to generate standard binocular images from heterogeneous binocular images of smartphone. A well-known YOLOv5s object detection model was trained on a four-class dataset to detect fruits, grafts, trunks and whole trees. Then, the model was simplified to fit the deployment on smartphone. Finally, five phenotypes (trunk diameter, ground diameter, tree height, fruit vertical diameter, and fruit horizontal diameter) of individual apple tree were obtained by pinhole camera model and standard binocular vision. After evaluation of phenotyping manually and by smartphone, our method shows MAPE (mean average percentage error) ranging from 6.00 % to 13.73 % for the five phenotypes. Compared with the existing studies, our method has reached a close or even better phenotyping accuracy with only a smartphone. As more and more smartphones have multi-camera, our method is probably the lowest cost phenotyping method for most of the potential users. Results indicated that the approach could be utilized to phenotyping of apple tree. [ABSTRACT FROM AUTHOR]

Due to shortages of fossil fuels, and the worldwide concern approximately climate change and global warming, biofuels have become an important source of sustainable energy. Several species can be used to produce biofuels such as soybeans ( Glycine max ), oil palm ( Elaeis guineensis ), and Jatropha ( Jatropha curcas L.). Therefore, the objective of this paper was to integrate the information available in the literature and report the most promising strategies for genetic and biotechnological progress in Jatropha. Jatropha has become a potential crop to produce biofuel due to the high oil content found in the seeds, which can be transformed into biofuel. Jatropha has an average seed oil content of 35%, and the oil extracted from the seeds has 24.6% crude protein and 47.2% crude fat. Moreover, Jatropha has several agronomic morphological traits that make it a useful crop for biofuel production and animal feed, such as drought tolerance, rapid growth, and ease of propagation. It can be grown at almost any altitude, and plants can produce for more than 50 years. Additionally, Jatropha oil has good stability to oxidation, low viscosity, a low pour-point, which makes Jatropha oil better than soybean or palm oil. This paper presented an innovative and comprehensive literature review on all agronomic aspects of Jatropha, and the strategies that have been used to select superior genotypes for Jatropha breeding. Several important traits of Jatropha are affected by the environment and new strategies to select superior genotypes are required by breeders. Therefore, genomic wide selection associated with recurrent selection can be an appropriate strategy for Jatropha breeding. [ABSTRACT FROM AUTHOR]

• BC 1 F 3 hybrid seedlings exhibited the largest total growth and incremental height growth. • Seedlings from the BC 3 F 3 generation had intermediate Cryphonectria parasitica resistance. • Phytophthora root rot contributed to mortality in planted chestnut seedlings. • High performing and poor performing BC 3 F 3 families could be identified. • Using larger size seedlings at planting will reduce time needed to obtain desired tree size. The American chestnut (Castanea dentata) is imperiled due primarily to two diseases caused by nonnative pathogens, notably chestnut blight and Phytophthora root rot (PRR) caused by Cryphonectria parasitica and Phytophthora cinnamomi , respectively. Field reintroduction trials are important to test trees bred for blight resistance under forest conditions to quantify survival and field performance in managed stands that represent future restoration sites. We planted 513 pedigreed bare-root (1–0) nursery seedlings into an even-aged regeneration harvest in the Blue Ridge Mountains of eastern Tennessee, USA to test effects of breeding, genetics, and seedling size class on field performance, including survival, total growth, incremental growth (a measure of growth efficiency), and height growth patterns. Mortality was highest in the first two years after planting, and PRR symptoms coupled with soil and root assays that tested positive for P. cinnamomi suggested this disease was a significant contributor to mortality. Chinese chestnut (C. mollissima), known to be resistant to P. cinnamomi and C. parasitica , had the highest survival (96 percent) compared to American chestnut (34 percent) and hybrid generations, including the BC 3 F 3 generation (41 percent). Less advanced hybrid generations, such as the BC 1 F 3 and BC 2 F 3 , had the greatest total height and ground-line diameter (GLD) and height growth efficiencies. BC 3 F 3 generation seedlings were associated with higher-than-expected rates of nominal height growth patterns (i.e., flat growth rates over time or early mortality) compared to Chinese chestnut seedlings. Results, however, indicated the breeding program was successfully integrating desired American chestnut growth traits into the hybrid genome while transferring an intermediate level of resistance from the Chinese chestnut. We identified superior and inferior BC 3 F 3 families that can help inform breeding and restoration efforts. Visually grading seedlings before planting affected survival and growth of generations and genetic families differently, indicating that refinement of nursery production and restoration plantings should consider genetic effects. Across generations, seedling size grading improved total height and GLD growth that would save resources necessary for competition control and animal browsing protection, but large-size seedlings also exhibited lower C. parasitica resistance rankings over time, probably owing to earlier bark fissuring. PRR probably affected outcomes, particularly for hybrid and American chestnut seedlings that have very low levels of P. cinnamomi resistance. Managers could expect advanced breeding generations to perform similarly to American chestnut in growth through the critical stage of early stand development. More durable resistance to C. parasitica and mitigation of PRR through better site selection and/or resistance screening will improve future restoration efforts. [ABSTRACT FROM AUTHOR]

• 459 proteins were found to show significant abundance alterations in leaves of UCB-1 under exposure to 200 mM NaCl stress. • Ribosome components, biosynthesis of phenylpropanoids, and carbon fixation in photosynthetic organisms were largely affected by salt stress. • Any alterations in the abundance of EMB3010, PA2, NAD-ME1, and PGAM proteins may result in desirable consequences on salt tolerance in UCB-1. • Centrality analysis of whole proteome survey-derived responsive PPIs is useful in identification, prioritization and selection of potential biomarker candidates. The hybrid pistachio rootstock UCB-1 is especially tolerant to abiotic stresses including salinity. However, the effect of salinity on its whole proteome is obscure, which limits our ability to develop high-confident protein biomarkers to facilitate the genetic improvement of pistachio cultivars with enhanced salt-tolerance. In the present study, using sequential window acquisition of all theoretical mass spectra (SWATH-MS) technology, the expression of 1150 proteins was quantified, with the expression of 459 proteins significantly impacted by salt exposure. Functional enrichment determined that salinity stress increases the level of proteins associated with response to salt stress and reduces the level of ribosomal subunits. We used KEGG pathway enrichment analysis to link salt exposure with a set of alterations in several pathways including ribosome components, biosynthesis of phenylpropanoids, and carbon fixation in photosynthetic organisms. To track the potential consequences of protein alteration with more crucial biological functions in the enriched pathways, the incorporation of SWATH-MS data and protein-protein interactions (PPIs) analysis were then conducted. Centrality analysis of the three top-ranked enriched pathways highlighted that any alterations in the abundance of EMB3010, PA2, NAD-ME1, and PGAM proteins may result in desirable consequences on salt tolerance in UCB-1. Therefore, centrality analysis of whole proteome survey-derived responsive PPIs was useful in the identification, prioritization, and selection of potential biomarker candidates by which the need for expensive and time-consuming experimental validation will be minimized. At the early selection stages in tree breeding programs, integration of proteomics-generated resources with conventional programs can assist in developing fast selection assays. [ABSTRACT FROM AUTHOR]

The growing concern of the impact of climate change in forestry has prompted tree improvement programs and regulatory agencies to integrate climate change adaptation in the production and use of tree seed. In support of such adaptation strategies, we conducted a case study for lodgepole pine ( Pinus contorta Dougl.) in Alberta, Canada. We compared the tree height for populations and families planted across 37 progeny and provenance trials when transferred among six physiogeographically and climatically distinct breeding regions. Based on these results we infer how lodgepole populations and families are adapted to current climate conditions and how they might respond to future changes in climate. Interestingly, in almost all regions we found that local populations grew better than introduced sources, suggesting that in the current climate the use of local populations is still an appropriate reforestation strategy with some exceptions. Notably, in cool and wet higher elevation environments (between 1050 and 1650 m), local populations were outgrown by populations originating from warmer lower elevation regions. Moreover, these higher elevation populations were always outgrown when transferred to other regions. A number of transfers among regions were identified that ensure productivity gains under recent climate conditions, and simultaneously represent a short term adaptation measure for warming of about +0.5 °C. Further, we provide a database for selection of families within breeding populations to enhance their resilience to climate change. [ABSTRACT FROM AUTHOR]

A two-generation maritime pine ( Pinus pinaster Ait.) breeding population ( n = 661) was genotyped using 2500 SNP markers. The extent of linkage disequilibrium and utility of genomic selection for growth and stem straightness improvement were investigated. The overall intra-chromosomal linkage disequilibrium was r 2 = 0.01. Linkage disequilibrium corrected for genomic relationships derived from markers was smaller ( r V 2 = 0.006 ). Genomic BLUP, Bayesian ridge regression and Bayesian LASSO regression statistical models were used to obtain genomic estimated breeding values. Two validation methods (random sampling 50% of the population and 10% of the progeny generation as validation sets) were used with 100 replications. The average predictive ability across statistical models and validation methods was about 0.49 for stem sweep, and 0.47 and 0.43 for total height and tree diameter, respectively. The sensitivity analysis suggested that prior densities (variance explained by markers) had little or no discernible effect on posterior means (residual variance) in Bayesian prediction models. Sampling from the progeny generation for model validation increased the predictive ability of markers for tree diameter and stem sweep but not for total height. The results are promising despite low linkage disequilibrium and low marker coverage of the genome (∼1.39 markers/cM). [ABSTRACT FROM AUTHOR]

The objectives of this study were to investigate genetic variation and association of the traits of the laticiferous system with rubber yield in young and adult rubber tree progenies Hevea brasiliensis , and compare the traits of the laticiferous system at different heights of the adult trees. The genetic material is composed of progenies from open pollination from the rubber tree breeding program of IAC, evaluated in the experimental field of UNESP in Ilha Solteira, SP, Brazil, in the young and adult phases, and in the Polo Regional Alta Mogiana of the Agência Paulista de Tecnologia do Agronegócio in Colina, SP, Brazil in the young phase. A randomized block experimental design was used with 30 treatments (progenies), three replications, and 10 plants per plot. The following traits were evaluated: rubber yield (RY), virgin bark thickness (BT), number of rings of laticiferous vessels (NR), and mean distance between consecutive rings of the laticiferous vessels (MD). The individual statistical analyses and repeated measurements were performed through mixed linear models using the REML/BLUP (Restricted Maximum Likelihood/Best Linear Unbiased Prediction) procedure. Genetic and phenotypic correlations were also estimated. The accuracy estimates ( A ˆ c) for the traits in the two locations were higher (> 0.7), indicating good perspectives in a breeding program. The coefficient of genetic variation (CVg %) showed low variation between the sites: BT (4.5–7 %), NR (14.1–18.3 %), and MD (15–18.2 %). The NR expressed higher heritabilities and was therefore the best trait of the laticiferous system for predicting genetic values; it showed expressive genetic correlations with RY, and may be used in indirect selection. BT did not show progeny × height interaction, indicating that the classification of the progenies was the same, regardless of the tree height at collection. To select progenies in common in the young and adult ages, using analysis of measurements repeated in time, the most suitable height for collection of samples in the adult progenies for the traits of the laticiferous system was up to 80 cm. The traits of the laticiferous system collected at 30 cm in young progenies are associated with RY, both in the youth phase and in the adult phase. They can be used to assist in early or indirect selection of rubber tree progenies. • The number of rings of laticiferous vessels is the trait of the laticiferous system that best associated with rubber yield. • Traits of the laticiferous system are of a heritable nature. • The genetic coefficients of variation of the traits of the laticiferous system show little variation in different situations. • There is association between traits of the laticiferous system collected at 30 cm height from ground level and rubber yield. [ABSTRACT FROM AUTHOR]

In this study, regularization algorithms (RR, LR, and ENR), classical ML algorithms (SVR, DT, and RF), and advanced GBM algorithms (LightGBM, CatBoost, and XGBoost) were applied to build the holocellulose content predictive models of poplar based on features extracted from Raman spectra. Evaluation results of models indicate that classical ML algorithms show higher predictive accuracy than regularization algorithms, and the advanced GBM algorithms better than the classical ML algorithms. Furthermore, models built by CatBoost and XGBoost can estimate holocellulose content with high predictive accuracy of test R2 above 0.93 and test RMSE less than 0.29%. It provides the heretofore best precision of holocellulose content predictive model based on Raman spectroscopy so far for our knowledge. Therefore, it is suggested that Raman spectroscopy coupled with ML algorithms is a promising tool for predicting the holocellulose content in poplar which can be applied in large-scale tree genetic and breeding programs. [Display omitted] • Models were developed to predict holocellulose content by machine learning algorithms. • CatBoost and XGBoost are better than other algorithms in predicting holocellulose. • A predictive model of holocellulose content with test R2 = 0.93 and RMSE = 0.28 is built. [ABSTRACT FROM AUTHOR]

In North America, the native hazelnut Corylus americana harbors an endemic fungus, Anisogramma anomala , which causes the disease eastern filbert blight (EFB). Although C. americana is tolerant of EFB, the economically important European hazelnut, C. avellana , is highly susceptible to the disease. This susceptibility greatly limits commercial European hazelnut production in North America. The breeding and subsequent utilization of resistant plants are considered the most effective means of control and efforts are underway to identify diverse sources of genetic resistance. In this study, 1374 C. avellana seedlings, spanning 47 seed lots collected in the Republic of Georgia and 3 in Azerbaijan, were inoculated with the EFB pathogen and evaluated for disease response in New Jersey, USA. After 5 years, plant responses were rated on a scale of 0–5, in which 0 represents no signs or symptoms of EFB and 5 represents all stems showing cankers. Cankers were found on over 94% of the seedlings, with the large majority being highly susceptible (91.4% = rating 4 and 5). However, 79 plants from 34 seed lots remained free of signs or symptoms of EFB (rating 0). In most cases, only one or two resistant seedlings were in each of these seed lots, making it difficult to infer any genetic control of resistance. In contrast, seed lots from ‘Gulshishvela’ and ‘Kharistvala’ yielded significant numbers of resistant plants, which may indicate that dominant genes for resistance are present. Overall, these new plants will add to the genetic resources available for breeding new EFB-resistant cultivars. [ABSTRACT FROM AUTHOR]

Highlights: [•] Eucalypt productivity is related to the interaction among the environment, genotype, management, pest and diseases. [•] The selection for eucalypt rust resistance in climatic conditions showed a simple genotype-environmental interaction. [•] There is good relationship between rust severity and theoretical model with annual average temperature and leaf wetness. [•] Heritability among the progenies was high, indicating improvement through progenies selection. [ABSTRACT FROM AUTHOR]

Abstract: Common ash (Fraxinus excelsior) is a keystone tree species throughout temperate Europe whose future existence is threatened by an emerging invasive fungal disease. Ash dieback, which first appeared in Poland in the 1990s, has rapidly spread to most eastern, central and northern European countries. The causal agent of the disease, the ascomycete Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea), was recently described as a new species. Given that the disease lethally affects ash trees of all age classes, and that ash tree mortality levels are high, F. excelsior and the many organisms dependent on ash trees are under threat. Based on a literature survey, we provide an overview of the present knowledge on ash dieback, identify practical recommendations and point out research needs. The observation of relatively resistant individual ash trees (although at very low frequency) calls for a rapid germplasm collection effort to establish a breeding program for resistance or tolerance to the disease. Ash trees that appear to be tolerant to the pathogen should not be felled, unless they pose an unacceptable risk to people’s security. Given that the pathogen does not form propagules on wood, and given the importance of deadwood for biodiversity conservation, dead and dying ash trees should be left in the forest. Landscape pathology and genetic tools can be used to reconstruct the dispersal pathways of H. pseudoalbidus and to identify environmental features associated with variation in disease severity, so as to better predict the further development of the epidemic. Observations on differences in susceptibility of various ash species are needed to locate the geographic origin of the pathogen and to identify Fraxinus species which might be used for resistance breeding or even replacement of F. excelsior. Conservation biologists, landscape managers, restoration ecologists, social scientists and tree geneticists need to engage with forest pathologists and the various stakeholders throughout the distributional range of F. excelsior so as to tackle this pressing conservation challenge. [Copyright &y& Elsevier]

• Macadamia selection. • Bioeconomic modeling. • Quantify preferences for trait improvements. This paper evaluates a novel approach in horticulture of using quantitative survey methodology to inform horticultural tree crop breeding objectives. Using the Australian macadamia breeding program as a case study, the aim was to elicit Australian macadamia industry stakeholder preferences for economical equivalent trait improvements, estimate preference heterogeneity, and identify associations with stakeholder characteristics. A total of 19 respondents participated in the survey, representing 20% of the Australian macadamia industry. Respondents displayed a high willingness to use pairwise comparison implemented in the 1000minds software. Respondents exhibited a wide variability in preferences, however, variation in average preference among trait improvement levels was not large, suggesting on average preferences were consistent with economic values of unit of trait change derived from an industry developed bio-economic model. Observed heterogeneity in preferences were not associated with respondents' role in industry, orchard size, or growing region. [ABSTRACT FROM AUTHOR]

• Drone-based imagery was employed for the genetic variation of tree growth traits. • The heritability of growth traits and vegetation indices varying in different sites. • Family selection was conducted for tree growth and vegetation indices traits. • Multispectral imaging is feasible in breeding selection of slash pine trees. Vegetation indices (VIs) are mainly associated with plant yield, and yield-related physiological traits can assist in breeding selection. Tree breeding programs require a rapid assessment of a large number of individual trees across multiple regions. Unmanned aerial vehicle (UAV) multispectral platforms combined with high spatial, temporal and spectral resolutions can readily assess the VIs at various plant growth phases, which has been deeply detailed for evaluating the physiological status of agricultural crops and forest stands. However, the underlying genetics of foliar spectral bands, VIs and growth traits from a large scale of samples, especially in the case of forest trees, have been less investigated. In this paper, two sites of slash pine breeding populations were completely investigated to monitor the spectral bands, VIs, and tree growth traits. This allows us to determine the genotypic variation of these traits and to estimate the heritability (h2). The results show that the estimated h2 ranges from 0.04 to 0.36, and the site may affect tree growth because the traits between two sites come to different h2 values. At the two sites, the h2 values of the green red difference vegetation index (GNDVI) and anthocyanin reflectance index (ARI) at Site 1 and the red edge chlorophyll index (RECI), leaf chlorophyll index (LCI), red green blue vegetation index (RGBVI), normalized difference red edge index (NDRE), NIR and red edge at Site 2 were less than 0.1. However, breeding selection is still possible for most VIs and growth traits at both sites based on different breeding targets and families (families 3, 5, 10, 11, 14 and 17 at Site 1 and 4, 6, 8, 19 and 13 at Site 2 for optimal spectral bands; families 2, 8, 7, 13, 16, and 18 at Site 1 and 6, 7, 11, 14, 15, 18, and 20 at Site 2 for optimal VIs; families 8 and 16 at Site 1 and families 7 and 18 at Site 2 for optimal growth traits) with a variety of optimal traits are selected. This paper demonstrates the potential use of UAV-based imagery technologies in the breeding selection of slash pine trees. [ABSTRACT FROM AUTHOR]

South American Leaf Blight (SALB), caused by Pseudocercospora ulei , is the most important disease in Hevea brasiliensis grown in South America. This study aimed to evaluate long-term resistance in the field for 11 years in 10 rubber tree genotypes (nine hybrid clones and one primary clone) in a large-scale clonal trial (LSCT) and under controlled and nursery conditions. Resistance was evaluated using two resistance components: type of reaction (TR, ranging from 1 to 6) related to asexual sporulation, and stroma density (ST, ranging from 0 to 4), which is linked to sexual sporulation. Resistance status ranking (RSR) based on the maximum scores of the variables was adapted to classify the genotypes (completely resistant, partially resistant or highly susceptible) over time, and against four indigenous isolates of P. ulei. Eight of the ten clones exhibited partial resistance in the field, and clones FDR 5597, GU 198 and FDR 5788 were more resistant with TR ≤ 4 and ST ≤ 2. These clones were completely resistant in the laboratory/nursery with TR < 3 and ST = 0. Only clone MDF 180 did not exhibit the sexual phase of the pathogen (i.e., ST = 0) in the field or in the nursery. Clones CDC 56 and IAN 873 (control) were highly susceptible, with TR > 5 and ST > 2. In this study, sources of partial resistance were evidenced for the effective management of SALB under conditions of high P. ulei incidence in the Amazon. • A disease resistance status ranking (RSR) based on sporulation is proposed. • In field, clones FDR 5597, GU 198 and FDR 5788 had the highest partial resistance. • High levels of partial resistance were observed during the hottest and drier years. • Highest resistance stability was evidenced in clones FDR 5597, MDF 180 and CDC 312. • In laboratory, higher levels of resistance were observed when compared to field. [ABSTRACT FROM AUTHOR]

Backcross breeding has provided a viable means to restore American chestnut (Castanea dentata (Marsh.) Borkh.) to eastern North American forests, where the foundation species was essentially extirpated by an introduced pathogen. With the prospect of American chestnut reintroduction imminent, it is critical to formulate restoration strategies based on the ecology and silvics of the species, operational confines, social or policy limitations, and ecological implications. American chestnut was apparently adapted to a relatively wide range of site conditions, has evolved a capacity to survive for prolonged periods beneath forest canopies yet respond rapidly to disturbance, and demonstrates extraordinary growth and competitive ability. These characteristics are discussed in reference to operative planting techniques and potential for migration of regeneration from hybrid chestnut plantings into forests of the original American chestnut range. The use of hybrid trees for American chestnut reintroduction may generate social and policy ambiguities that require conciliation. Additionally, potential long-term ecological implications associated with reintroduction of American chestnut to the original species range, or introduction to areas outside its original range, must be realized and integrated into reintroduction strategies. Limitations in genetic fitness, potential for disease mutation, and threats from other exotic insects and pathogens may serve as continual challenges to American chestnut restoration. This paper helps establish preliminary guidelines for restoration plantings and creates awareness of imposing ecological issues and barriers that must be overcome to successfully restore American chestnut to its natural range, while simultaneously maintaining ecological integrity and ensuring conservation benefits to eastern North American forests. [Copyright &y& Elsevier]

Abstract: The influence of initial stand density, genotype, propagation method and physiologically aged cuttings on outerwood dynamic modulus of elasticity (E) of 17-year-old Pinus radiata was examined at a Nelder spacing experiment in Canterbury, New Zealand. Outerwood dynamic modulus of elasticity was determined using the stress wave method on 385 trees in one Nelder plot. The experiment incorporated three genetic breeding series (850, 870 and 268 series), two propagation methods from the 268 series (seedlings and cuttings) and two different physiologically aged cuttings (cuttings taken from 1-year-old and 3-year-old parents) grown at 10 different initial stand densities ranging from 209 to 2551stemsha−1. Dynamic modulus of elasticity was significantly influenced by initial stand density (P <0.0001) and genotype (P <0.0001), but not their interaction. Dynamic modulus of elasticity increased by 39%, from 5.4 to 7.5GPa, between 209 and 2551stemsha−1, with the majority of this increase (33%) occurring between 209 and 835stemsha−1. The 3-year-old cuttings exhibited the highest E of 7.7GPa, which significantly exceeded E for the 1-year-old cuttings, and seedlings from the 870, 268, and 850 breeding series by 15, 17, 22, and 26%, respectively. Stem slenderness (height/diameter) exhibited the strongest relationship with E (r 2 =0.49), displaying a significant (P <0.0001) positive linear correlation. Dynamic modulus of elasticity also exhibited a significant (P <0.0001) positive linear relationship with green crown height (r 2 =0.46) and a significant (P <0.0001) negative linear relationship with diameter at breast height (r 2 =0.44). The final path analysis model included stem slenderness and green crown height as significant positive direct influences on E explaining 53% of the variance in the dataset. Tree diameter and height were indirectly associated with E through their significant direct relationship with stem slenderness and green crown height. This study demonstrates the strong influence of initial stand density on E and suggests that the use of physiologically aged cuttings of greater maturation status improves E. Results also strongly suggest that the effects of diameter and height on E are mediated through stem slenderness and green crown height. [Copyright &y& Elsevier]

Abstract: Pinus oocarpa has a large natural distribution in the sub-tropical forests of Mexico. Populations, however, are rapidly disappearing particularly in the Michoacán State as native forests are converted to avocado (Persea sp.) orchards. We investigated the patterning of genetic variation among P. oocarpa populations for quantitative traits along an altitudinal gradient by establishing a provenance/progeny test from wind-pollinated seeds collected along an altitudinal transect (1100–1500m) near Uruapan, Michoacán, Mexico. Genetic variation was analyzed in relation to normalized climate records (temperature, precipitation, degree days >5°C and annual moisture index) for the provenances and the test site for the contemporary climate and for climates projected for the decades beginning in 2030, 2060, and 2090. Estimates of future climates used output from the Canadian and Hadley General Circulation Models. Results of a field test suggested an altitudinal pattern of genetic differentiation in juvenile height among P. oocarpa populations. Seedlings from populations originating from lower altitudes tended to grow more than seedlings originating from populations at the higher altitudes. However, this trend abates at the lowest altitudinal limit of the species distribution, a probable conservative growth strategy for avoiding drought stress. Thus, the cline appeared to arise from selection along a climatic gradient reflecting in a moisture index (ratio of degree days to precipitation) and is dependent, therefore, on a balance between temperature and moisture. For guiding seed and seedling transfer in ecological restoration, conservation of genetic resources, tree breeding and mitigating the effects of global warming, we suggest guidelines based on delimitation of three altitudinal seed zones of about 200m in breadth. Alternatively, one can limit transfer to three climatic zones of about 0.75 units of annual moisture index. Predictions of future climates indicate an average annual temperature increase of 3.8°C by year 2090, and, judging from an increase of an annual moisture index of 26%, an increase in aridity by the end of the century. However, the more difficult period for adaptation of P. oocarpa populations to the new climate should be between 2030 and 2060, when the increase in aridity is expected to be most pronounced. Changes of this magnitude should alter the natural distribution of the species and would create an adaptational lag, as the adaptedness of extant populations deteriorates. Mitigating these effects will require seeds to be transferred upwards in altitude, perhaps as much as 150m initially. [Copyright &y& Elsevier]

Tree peony (Paeonia Sect. Moutan) is widely grown as an ornamental plant and is known for its 'National Beauty and Heavenly Fragrance '. However, the genetic improvement of floral scent traits is fundamentally limited by the paucity of genomic marker resources. Given the large-scale development of microsatellite markers using transcriptome sequences, we conducted an association analysis to identify microsatellite markers associated with main floral components. A total of 8,443 EST-SSRs were identified, with an average of one SSR per 15.55 kb. Di-nucleotide repeats were the most plentiful repeat type, followed by tri-, tetra-, penta- and hexa-nucleotide repeats. Among 969 synthesized primer pairs, 499 were successfully amplified and 136 showed polymorphism which exhibited relatively high levels of transferability were observed across 12 individuals in the genus Paeonia , thus expanding their utility. Subsequently, 31 polymorphic EST-SSR markers were selected for the analysis of genetic diversity and population structure, resulting in 176 alleles; the polymorphism information content (PIC) varied from 0.31 to 0.87. According to the population structure analysis, the association varieties were divided into three subgroups. Finally, single marker-trait association analysis based on mixed linear model (MLM) identified 29 significant associations, involving five floral components with 18 SSRs and a low proportion of phenotypic variance ranging from 4.57 to 23.46%. The newly developed markers were valuable resources that could provide a powerful genomic tool for genetic studies and accelerate the process of molecular marker-assisted breeding of tree peony floral scent. [ABSTRACT FROM AUTHOR]

• The highest total variability was explained by the genotype effect (G) in the whole development stage of Chinese fir, the influence of genotype increased through time. • The risk of early selection was verified from the perspective of mature forest, and 70% of excellent provenances would be missed in the young forest stage (5-year-old). • The provenances with of excellent productivity Chinese fir showed aggregation distribution at mature forest stage. It is particularly important to select the provenance with better adaptability in the context of the counteracting potential adverse effects of climate change. However, the growth environment of trees and the length of breeding cycle determine the uncertainty of early selection. Thereby, it is advisable to provide information for provenance selection by analyzing the relationship between young, middle and mature forests. Chinese fir(Cunninghamia lanceolata (Lamb.) Hook.) is an evergreen coniferous tree species with rapid growth and high-quality timber, and it is an important reforestation and commercial tree species in South China. The provenance experimental forests of Chinese fir in Jiangxi and Guangxi were taken as the test object, the growth survey went by three stages of growth: young, middle and mature ages. The linear mixed model was used to evaluate the differentiation of different forest stage provenances in terms of growth. K-medoids clustering algorithm was used to group provenances, the geographical distribution characteristics of Chinese fir were evaluated based on the major groups, and the risk of early selection and the genetic gain of excellent provenances were calculated. The highest total variability was explained by the genotype effect (G) in the young, middle-aged and mature forest stage, the influence of genotype increased through time, while the influence of site was reduced and the G×E interaction changed in a small range. The differences in heritability were similar between young and middle-aged forests, but the heritability of growth traits was higher at Jiangxi than Guangxi in the mature forest stage. The provenances with excellent productivity Chinese fir showed aggregation distribution at the mature forest stage, and the provenances with worst growth were mainly distributed in the northern marginal production area. [ABSTRACT FROM AUTHOR]