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Eucalyptus camaldulensis is a multifunctional tree and is globally used for the reclamation of problematic lands. Eucalyptus camaldulensis is prone to attack by a number of pathogens, but the most important threat is the Fusarium wilt (Fusarium oxysporum). Keeping in view the importance of E. camaldulensis and to manage this disease, five plant activators, i.e., salicylic acid (C7H6O3), benzoic acid (C7H6O2), citric acid (C6H8O7), dipotassium phosphate (K2HPO4), monopotassium phosphate (KH2PO4) and nutritional mixture namely Compound (NPK) and nutriotop (Fe, Zn, Cu, B, Mn) were evaluated in the Fusarium infested field under RCBD in the Research Area, Department of Forestry and Range Management, University of Agriculture, Faisalabad (UAF). Among plant activators, salicylic acid and a combination of compound + nutriotop exhibited the lowest disease incidence and enhanced fresh and dry weight of leaves compared to other treatments and control. Results of the environmental study indicated maximum disease incidence between 35-40 °C (max. T), 6-25 °C (mini. T), 70-80% relative humidity and 1.5-2.5 km/h wind speed while pan evaporation expressed weak correlation with disease development. It was concluded that Fusarium wilt of Eucalyptus camaldulensis could be managed through activation of the basal defense system of the host plant with provision of salicylic acid and balanced nutrition by considering environmental factors. Recent exploration is expected to be helpful for future research efforts on epidemiology and ecologically sound intervention of Fusarium wilt of Eucalyptus camaldulensis.

Natural environments have undergone significant alteration and devastation, often becoming immersed in a matrix of anthropogenic activities. Therefore, it is imperative to ascertain whether mammals inhabit these modified areas. We present the composition of medium and large-sized terrestrial mammal species in a Cerrado area surrounded by a eucalyptus matrix. Our study area comprises a 363 ha Cerrado fragment. Surveys were conducted using 10 camera traps from December 2015 to April 2017, totaling 125 sampling stations and a sampling effort of 3,018 trap-days. We identified 19 mammal species, seven of them regionally threatened (37 %), representing 61 % of the potential species pool in the region. Omnivores and insectivores accounted for most of the recorded species. Notably, records include the Priodontes maximus, Tapirus terrestris, and Ozotoceros bezoarticus, cubs and a predation record. Given that T. terrestris was recorded only in our study and P. maximus in a single other study in the region, our findings suggest that these species can inhabit small vegetation fragments. Additionally, we include O. bezoarticus in the list of mammals inhabiting the region. Our study underscores the capacity of Cerrado fragments surrounded by silviculture to harbor a rich diversity of medium and large-sized mammals, especially considering those threatened with extinction. [ABSTRACT FROM AUTHOR]

Galls are thought to be induced by insects for protection, yet many gall‐forming insects experience heavy parasitization. Little is known about how parasitoids locate gall‐forming insects. Quadrastichus mendeli Kim & La Salle (Hymenoptera: Eulophidae) is an obligate ectoparasitoid of the larvae of Leptocybe invasa Fisher et La Salle (Hymenoptera: Eulophidae), which is an invasive gall‐forming pest in eucalyptus (Eucalyptus spp., Myrtaceae) plantations. In this study, Q. mendeli and L. invasa were used to explore parasitoid behavior when locating gall‐forming insects. Our results revealed that host location by Q. mendeli involved five discrete steps: walking, resting or grooming, antennating, probing and stinging. Antennation was the most frequent behavior, accounting for about half of the total time. Host location behavior of Q. mendeli occurred in the photophase. Female Q. mendeli exhibited a clear circadian rhythm: Almost all behaviors occurred during the photophase, and behavior peaked at the sixth hour of the light phase. The olfactory response rates of Q. mendeli to volatiles from galls decreased significantly after their antennae were detached. However, there was no significant difference in the host location behavior of Q. mendeli after their eyes were obscured. Our results provide essential information to explore the host location mechanisms in gall parasitoids. [ABSTRACT FROM AUTHOR]

Genomic Selection (GS) in tree breeding optimizes genetic gains by leveraging genomic data to enable early selection of seedlings without phenotypic data reducing breeding cycle and increasing selection intensity. Traditional assessments of the potential of GS in forest trees have typically focused on model performance using cross-validation within the same generation but evaluating effectively realized predictive ability (RPA) across generations is crucial. This study estimated RPAs for volume growth (VOL), wood density (WD), and pulp yield (PY) across four generations breeding of Eucalyptus grandis. The training set spanned three generations, including 34,461 trees with three-year growth data, 6,014 trees with wood quality trait data, and 1,918 trees with 12,695 SNPs (single nucleotide polymorphisms) data. Employing single-step genomic BLUP, we compared the genomic predictions of breeding values (GEBVs) for 1,153 fourth-generation full-sib seedlings in the greenhouse with their later-collected phenotypic estimated breeding values (EBVs) at age three years. RPAs were estimated using three GS targets (individual trees, trees within families, and families), two selection criteria (single- and multiple-trait), and training populations of either all 1,918 genotyped trees or the 67 direct ancestors of the selection candidates. RPAs were higher for wood quality traits (0.33 to 0.59) compared to VOL (0.14 to 0.19) and improved for wood traits (0.42 to 0.75) but not for VOL when trained only with direct ancestors, highlighting the challenges in accurately predicting growth traits. GS was more effective at excluding bottom-ranked candidates than selecting top-ranked ones. The between-family GS approach outperformed individual-tree selection for VOL (0.11 to 0.16) and PY (0.72 to 0.75), but not for WD (0.43 vs. 0.42). Furthermore, higher levels of relatedness and lower genotype by environment (G × E) interaction between training and testing populations enhanced RPAs for VOL (0.39). In summary, despite limited effectiveness in ranking top VOL individuals, GS effectively identified low-performing individuals and families. These multi-generational findings underscore GS's potential in tree breeding, stressing the importance of considering relatedness and G × E interaction for optimal performance. [ABSTRACT FROM AUTHOR]

Introduction: Wood formation is a crucial developmental stage in the life cycle of a woody plant; this process has substantial scientific research implications and practical applications. However, the mechanisms underlying woody plant development, especially the process of wood formation, remain poorly understood. As eucalyptus is one of the fastest growing tree species in the world, understanding the mechanism of wood formation in eucalyptus will greatly promote the development of molecular breeding technology for forest trees. Results: In this study, we investigated the proteomic profile of immature xylem at four different ages of Eucalyptus urophylla × Eucalyptus grandis (E. urograndis) using iTARQ technology. We identified 5236 proteins and 492 differentially abundant proteins (DAPs). The expression profiles of the DAPs corresponding to coding genes associated with wood formation were assessed using qRT-PCR. From the different expression profiles, it is inferred that the genes encoding kinesin, CDKD3, EXPA13, EXPA2, XTH27, EGases, UGT76E2, LAC, CCoAMT, CesA3, PAL, and CAD may undergo posttranscriptional regulation (PTR). Additionally, the genes encoding EIN2, ETR, MC4-like, and XCP may undergo posttranslational modifications (PTMs). Conclusions: We investigated changes in wood formation-related proteins at the protein abundance level in the immature xylem of E. urograndis , thereby elucidating potential regulatory mechanisms of key proteins involved in eucalyptus wood formation. This study may provide theoretical guidance for further research on molecular breeding techniques and genetic improvement related to the cultivation of rapidly growing and high-quality trees. [ABSTRACT FROM AUTHOR]

Micropropagation is an important tool for the propagation for recalcitrant species, like Eucalyptus cloeziana. This is a first reported about a complete study of the E. cloeziana, it includes the vegetative rescue protocol of mature trees, its micropropagation up to the implementation of a mini-garden and clonal micro-garden and evaluation of adventitious rooting of their propagules. The in vitro rejuvenation of E. cloeziana genotypes (03, 05, 06, 13 and 15), over 21 successive subcultures, was evaluated by comparing minicutting and microcutting techniques and the efficiency of this biotechnological tool for cloning of the mature trees. The results provide evidence of the in vitro rejuvenation occurring in the mature E. cloeziana trees during micropropagation, leading to increases in the multiplication ratios of the microstumps of three genotypes (03, 05 and 15). The survival and callogenesis percentages of the mini and microcuttings of E. cloeziana were higher than 80% upon exiting of the greenhouse (30-days old) in the three cutting times. The results suggesting that factors beyond tissue maturity influence the adventitious rooting of the E. cloeziana because minicuttings and microcuttings of the 05 and 13 elite genotypes exhibited rooting percentages lower than 20%. These findings provided a theoretical basis for realizing the micropropagation of the epicormic shoots of the mature trees and, subsequently, its in vitro rejuvenation by axillary bud proliferation. [ABSTRACT FROM AUTHOR]

A new genus and species of the Anguinidae, Turbiditylenchus corticeus n. gen., n. sp., was isolated from the bark of Eucalyptus macrorhyncha from southeastern Australia. Turbiditylenchus corticeus is readily differentiated from all recognised anguinid genera and is characterised primarily by a slender body, lateral field with six incisures, an anteriorly flattened lip region continuous with the body, delicate stylet 7.9-9.9 μm long, muscular median bulb containing a strongly refractive valve, post-vulval uterine sac 1.87-4.4 times vulval body diam., conical tail with pointed tip, and males with leptoderan bursa and spicules 20.5-25.8 μm in length. The phylogenetic relationships of the new species with other anguinid lineages were reconstructed using sequences of the small subunit ribosomal RNA (18S rRNA), the internal transcribed spacer region (ITS; comprising ITS1-5.8S-ITS2) and partial large subunit ribosomal RNA (28S rRNA D2-D3) genes based on Bayesian inference and maximum likelihood analyses. These analyses demonstrate the new species represents a lineage distinct from all other anguinids. Based on phylogenetic results we also transfer Ditylenchus parvicauda Gu, Ma, Castillo & Munawar, 2024 and Ditylenchus gracicauda Gu, Ma, Castillo & Munawar, 2024 to Ditylenchoides Subbotin & Ryss, 2024 as Ditylenchoides parvicauda n. comb. and Ditylenchoides gracicauda n. comb. [ABSTRACT FROM AUTHOR]

In plant biology research, X-ray computed tomography (CT) has been demonstrated to be useful for studying the complex tissues of trees qualitatively and quantitatively. The cambium plays a very important role in plant growth and development. However, this tissue is relatively poorly studied due to its complex nature and its localization between layers of xylem and phloem cells. Antecedent environmental conditions may have a substantial impact on plant responses to drought and recovery dynamics. Therefore, this study aimed to investigate the impact of previous drought exposure on the 3D microstructure of two commercial Eucalyptus clones by monitoring the development of the cambium, in the same plant and same area of cambial tissue, during a 4-week trial consisting of well-watered, mild drought, severe drought, and rewatering phases. To track microstructural changes, the plants were imaged weekly with non-destructive X-ray micro-computed tomography (μCT). On the last day of the experiment, X-ray nano-CT was also performed. Our results indicate that trees subjected to earlier well-watered conditions were more affected by the severe drought, compared to those previously exposed to mild drought conditions. Thus, previous exposure to water deficit may provide the benefit of increased drought tolerance during future water deficit. Previous mild drought exposure can facilitate morphological adjustments, which potentially enhances drought tolerance during subsequent drought events. [ABSTRACT FROM AUTHOR]

Amyloid fibril formation is associated with various amyloidoses, including neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Despite the numerous studies on the inhibition of amyloid formation, the prevention and treatment of a majority of amyloid-related disorders are still challenging. In this study, we investigated the effects of various plant extracts on amyloid formation of α-synuclein. We found that the extracts from Eucalyptus gunnii are able to inhibit amyloid formation, and to disaggregate preformed fibrils, in vitro. The extract itself did not lead to cell damage. In the extract, miquelianin, which is a glycosylated form of quercetin and has been detected in the plasma and the brain, was identified and assessed to have a moderate inhibitory activity, compared to the effects of ellagic acid and quercetin, which are strong inhibitors for amyloid formation. The properties of miquelianin provide insights into the mechanisms controlling the assembly of α-synuclein in the brain. [ABSTRACT FROM AUTHOR]

Eucalyptus is a widely planted species in plantation forests because of its outstanding characteristics, such as fast growth rate and high adaptability. Accurate and rapid prediction of Eucalyptus biomass is important for plantation forest management and the prediction of carbon stock in terrestrial ecosystems. In this study, the performance of predictive biomass regression equations and machine learning algorithms, including multivariate linear stepwise regression (MLSR), support vector machine regression (SVR), and k-nearest neighbor (KNN) for constructing a predictive forest AGB model was analyzed and compared at individual tree and stand scales based on forest parameters extracted by Unmanned Aerial Vehicle–Light Detection and Ranging (UAV LiDAR) and variables screened by variable projection importance analysis to select the best prediction method. The results of the study concluded that the prediction model accuracy of the natural transformed regression equations (R2 = 0.873, RMSE = 0.312 t/ha, RRMSE = 0.0091) outperformed that of the machine learning algorithms at the individual tree scale. Among the machine learning models, the SVR prediction model accuracy was the best (R2 = 0.868, RMSE = 7.932 t/ha, RRMSE = 0.231). In this study, UAV-LiDAR-based data had great potential in predicting the AGB of Eucalyptus trees, and the tree height parameter had the strongest correlation with AGB. In summary, the combination of UAV LiDAR data and machine learning algorithms to construct a predictive forest AGB model has high accuracy and provides a solution for carbon stock assessment and forest ecosystem assessment. [ABSTRACT FROM AUTHOR]

Effective detection techniques are important for wildlife monitoring and conservation applications and are especially helpful for species that live in complex environments, such as arboreal animals like koalas (Phascolarctos cinereus). The implementation of infrared cameras and drones has demonstrated encouraging outcomes, regardless of whether the detection was performed by human observers or automated algorithms. In the case of koala detection in eucalyptus plantations, there is a risk to spotters during forestry operations. In addition, fatigue and tedium associated with the difficult and repetitive task of checking every tree means automated detection options are particularly desirable. However, obtaining high detection rates with minimal false alarms remains a challenging task, particularly when there is low contrast between the animals and their surroundings. Koalas are also small and often partially or fully occluded by canopy, tree stems, or branches, or the background is highly complex. Biologically inspired vision systems are known for their superior ability in suppressing clutter and enhancing the contrast of dim objects of interest against their surroundings. This paper introduces a biologically inspired detection algorithm to locate koalas in eucalyptus plantations and evaluates its performance against ten other detection techniques, including both image processing and neural-network-based approaches. The nature of koala occlusion by canopy cover in these plantations was also examined using a combination of simulated and real data. The results show that the biologically inspired approach significantly outperformed the competing neural-network- and computer-vision-based approaches by over 27%. The analysis of simulated and real data shows that koala occlusion by tree stems and canopy can have a significant impact on the potential detection of koalas, with koalas being fully occluded in up to 40% of images in which koalas were known to be present. Our analysis shows the koala's heat signature is more likely to be occluded when it is close to the centre of the image (i.e., it is directly under a drone) and less likely to be occluded off the zenith. This has implications for flight considerations. This paper also describes a new accurate ground-truth dataset of aerial high-dynamic-range infrared imagery containing instances of koala heat signatures. This dataset is made publicly available to support the research community. [ABSTRACT FROM AUTHOR]

The cotton bollworm, Helicoverpa armigera (Hübner), is one of the important insect pests of cotton throughout the world. Considering the adverse effects of chemical pesticides, it is necessary to find eco-friendly substitute agents for managing insect pests, including H. armigera. Plant-derived insecticides have been introduced as suitable candidates to replace detrimental synthetic chemicals. In this study, the toxicities of water, ethanol, and n-hexane extracts of eucalyptus and thyme, as well as their wettable powder formulations, against H. armigera larvae were investigated. The treated larvae represented different degrees of abnormalities, such as larva-pupa intermediate and pupa-adult stages in their different ages until they turned into pupae and completed the breeding cycle. The results showed that the considered formulations of extract of n-hexane and ethanol, and concentrations had significant effects on the mortality rates of the larvae (P≤0.05) but the interaction of extracts and concentrations was not significant. The mortality rates were enhanced by increasing the tested concentrations. The LC50 values (lethal concentrations to kill 50% of the tested insects) were 343.758% (water), 10.171% and 23.264% (ethanol), and 0.404% and 0.490% (n-hexane) for the eucalyptus and thyme extracts within 24 hours, respectively, indicating higher toxicities of n-hexane extracts. The LC50 values of wettable powder formulations of the thyme and eucalyptus extracts were 120.68% and 177.75% (water) and 36.17% and 74.65% (ethanol), respectively, which represented the greater toxicities of these types of formulations. Therefore, the wettable powder formulations of ethanol and water extracts of thyme were more toxic than their solution formulations. Based on the results of this study, wettable powder formulation of eucalyptus and thyme extracts had promising potential for H. armigera management. [ABSTRACT FROM AUTHOR]

In view of developing upcycling strategies for hardwood Kraft lignin, hydroxy-methylation of Eucalyptus Kraft lignin under alkaline conditions (pH 9 and 11) at different temperatures (50 °C and 70 °C) was studied in the present effort with the double objective of optimizing the reaction conditions and understanding the functionalization mechanism of C5 in either terminal or internal guaiacyl units during hydroxy-methylation. Formaldehyde consumption was estimated via titration of the oximated free formaldehyde; the hydroxy-methylation degree under the reaction was estimated by calculating the ratio in Condensed hydroxyl/Guaiacyl (Condensed OH/G-OH) via a new difference UV-spectroscopy. The reliability of the difference UV-method results for the analyses of the hydroxy-methylated lignins was statistically analysed and compared with that of vacuum-dried and sonicated samples. Hydroxy-methylated samples were then fully characterised by NMR (31P and HSQC) and GPC. The reaction temperature of 50 °C, pH 11, and period time of one hour resulted as the optimal conditions for the hydroxy-methylation, preventing the side-reactions leading to the formation of dimethylene-glycol addition products. The 31P and 1H–13C HSQC NMR revealed the absence of undesirable formaldehyde Cannizzaro by-products and the lack of hydroxymethyl groups in the aliphatic side chain under the studied conditions. GPC analyses, comparing two methodologies, revealed increases in molar mass of the hydroxy-methylated samples upon the formaldehyde addition. The selective hydroxy-methylation at the C5 guaiacyl site demonstrates that Eucalyptus Kraft lignin is as a promising candidate for resol production. [ABSTRACT FROM AUTHOR]

The aim of this trial was to assess the effectiveness of Sediflù, a medical device containing active herbal ingredients, on nocturnal and diurnal persistent coughs in children, with a duration of 3 to 7 days. Children with a dry and/or productive cough were enrolled in this prospective, interventional, multicenter, placebo-controlled, double-blind, randomized clinical study. Clinical efficacy was assessed through the evaluation of the soothing action of Sediflù against dry and/or productive coughing, both at night and during the day, and other effects of coughing associated with quality of sleep: frequency, child's quality of sleep, parental quality of sleep and severity. Treatment with Sediflù improved both night-time and day-time cough scores from day 2. The diurnal score also improved significantly in the Sediflù group at days 3 and 7. Sediflù syrup can be considered a valid treatment for cough management in younger children with upper respiratory tract infections, shortening the cough duration. [ABSTRACT FROM AUTHOR]

Biotic factors in fungal exudates impact plant-fungal symbioses establishment. Mutualistic ectomycorrhizal fungi play various ecological roles in forest soils by interacting with trees. Despite progress in understanding secreted fungal signals, dynamics of signal production in situ before or during direct host root contact remain unclear. We need to better understand how variability in intra-species fungal signaling at these stages impacts symbiosis with host tissues. Using the ECM model Pisolithus microcarpus , we selected two isolates (Si9 and Si14) with different abilities to colonize Eucalyptus grandis roots. Hypothesizing that distinct early signalling and metabolite profiles between these isolates would influence colonization and symbiosis, we used microdialysis to non-destructively collect secreted metabolites from either the fungus, host, or both, capturing the dynamic interplay of pre-symbiotic signalling over 48 hours. Our findings revealed significant differences in metabolite profiles between Si9 and Si14, grown alone or with a host root. Si9, with lower colonization efficiency than Si14, secreted a more diverse range of compounds, including lipids, oligopeptides, and carboxylic acids. In contrast, Si14's secretions, similar to the host's, included more aminoglycosides. This study emphasizes the importance of intra-specific metabolomic diversity in ectomycorrhizal fungi, suggesting that early metabolite secretion is crucial for establishing successful mutualistic relationships. • Microdialysis was used to sample secreted metabolites non-destructively in situ • Two isolates of Pisolithus microcarpus has contrasting host colonization ability • The two isolates had significantly different metabolite profiles under axenic state • The isolate with lower root colonization produced a more diverse array of compounds • Metabolites from the isolate with higher colonization efficiency mirrored the host [ABSTRACT FROM AUTHOR]

Summary: Polysaccharide structural complexity not only influences cell wall strength and extensibility but also hinders pathogenic and biotechnological attempts to saccharify the wall. In certain species and tissues, glucuronic acid side groups on xylan exhibit arabinopyranose or galactose decorations whose genetic and evolutionary basis is completely unknown, impeding efforts to understand their function and engineer wall digestibility.Genetics and polysaccharide profiling were used to identify the responsible loci in Arabidopsis and Eucalyptus from proposed candidates, while phylogenies uncovered a shared evolutionary origin. GH30‐family endo‐glucuronoxylanase activities were analysed by electrophoresis, and their differing specificities were rationalised by phylogeny and structural analysis.The newly identified xylan arabinopyranosyltransferases comprise an overlooked subfamily in the GT47‐A family of Golgi glycosyltransferases, previously assumed to comprise mainly xyloglucan galactosyltransferases, highlighting an unanticipated adaptation of both donor and acceptor specificities. Further neofunctionalisation has produced a Myrtaceae‐specific xylan galactosyltransferase. Simultaneously, GH30 endo‐glucuronoxylanases have convergently adapted to overcome these decorations, suggesting a role for these structures in defence. The differential expression of glucuronoxylan‐modifying genes across Eucalyptus tissues, however, hints at further functions.Our results demonstrate the rapid adaptability of biosynthetic and degradative carbohydrate‐active enzyme activities, providing insight into plant–pathogen interactions and facilitating plant cell wall biotechnological utilisation. See also the Commentary on this article by Mortimer & Scheller, 244: 749–751. [ABSTRACT FROM AUTHOR]

The forestry and pulp industry in Chile has been a significant contributor to the country's gross domestic product (GDP), accounting for over 1.2% between 2018 and 2022. This sector is expected to continue growing in the coming years. The purpose of this study was to assess the environmental performance of the production of 1 tonne of short fibre bleached cellulose using the Kraft process in Chile. The assessment focused on quantifying the impact in 10 life-cycle impact categories, utilising the ReCiPe 2016 Midpoint (H) V.1.03 impact method. The evaluation followed a cradle-to-gate approach, considering the various stages including forestry activities involving biocides, fertilisers, and machinery, as well as transportation, and the subsequent industrial stage encompassing chemicals consumption, electricity usage, fuel consumption, and waste disposal. The assessment adhered to the life-cycle assessment guidelines specified in ISO 14040-44:2006 and utilised primary data from 2017, with a base year production of 1,495,000 tonnes of pulp. The results revealed that the industrial stage had the most significant environmental impact in eight out of the ten categories studied. Notably, the Global Warming Potential (GWP) reached 784 kg CO2eq/tonne of cellulose, which is noticeably higher in comparison to other countries but consistent with domestic and Ecoinvent 3.4 results. Additionally, biogenic emissions reached 3140 kg CO2biogenic/tonne of cellulose, primarily due to the combustion of waste wood and black liquor for energy recovery and electricity generation delivered to the national grid. The forestry stage was found to be the primary contributor to marine eutrophication (MAEU) and stratospheric ozone depletion (SOD), accounting for up to 86% of this environmental impact category. These results can be attributed to the usage of chemicals such as nitrogen-based fertilisers and biocides (fungi and herbicides). These findings provide quantified information that can facilitate informed comparisons with similar processes and aid in decision-making to improve the forestry-industrial sector. Emphasis should be placed on those activities that have the most significant impacts on the Chilean pulp sector, thereby promoting sustainable practices and mitigating environmental consequences. [ABSTRACT FROM AUTHOR]

Ralstonia solanacearum and R. pseudosolanacearum are well-known bacterial plant pathogens that cause significant losses to both ornamental and agricultural plants. It has been suggested that they are not the primary cause of bacterial wilt in Eucalyptus species, but rather are opportunistic, taking advantage of trees predisposed to infection by abiotic and biotic factors. To test this hypothesis, the bacterial community within the vascular tissue of asymptomatic Eucalyptus grandis x E. urophylla trees, and those displaying varying stages of infection in China and Indonesia were compared using 16S rRNA profiling. Asymptomatic trees growing in areas where bacterial infections had never previously been reported to occur were included as controls. Ralstonia species were found within the vascular tissue of both asymptomatic and symptomatic trees, in high abundance. In the control samples, bacterial diversity within the vascular tissue was high with a low abundance of Ralstonia species. The presence of Ralstonia species in asymptomatic and control samples supports the hypothesis that these species are latent and/or opportunistic pathogens in E. grandis x E. urophylla trees. [ABSTRACT FROM AUTHOR]

The changes in soil chemical attributes in agrosilvopastoral systems after the thinning of trees are unclear. To address this gap, this study evaluated the effects of the thinning of eucalyptus hybrid Urograndis H-13 (Eucalyptus urophylla S. T. Blake × E. grandis W. Hill ex Maiden) on soil chemical fertility in an agrosilvopastoral system in an Arenic Hapludalf in Brazil. The experimental design was a randomized block with a 3 × 4 factorial design comprising three treatments (thinning of 0%, 50%, or 100% of the eucalyptus trees) and four sampling positions relative to the eucalyptus line (0, 2.0, 4.0, and 6.0 m). Six years after eucalyptus thinning, soil acidification was observed in the 0% and 50% eucalyptus thinning treatments, especially at 0 and 2 m from the eucalyptus line. Decreases in soil pH were associated with increases in the total acidity pH 7.0 (H+ + Al3+) and Al3+ content and decreases in the K+, Ca2+, and Mg2+ contents and base saturation over the soil profile (0–1.0 m). [ABSTRACT FROM AUTHOR]

Although recent studies have reported stimulatory effect of trinexapac-ethyl (TE) on eucalyptus growth, there is no consensus regarding the best dose to promote this response. Since TE acts in the gibberellin (GA) biosynthesis pathway, the study of hormonal crosstalk between the leaves and the shoot apical bud (SAB) can provide important information for understanding the positive effect previously reported. We evaluate the TE dose–response curve for eucalyptus growth in different soil moisture conditions (well watered—WW and 40% of field capacity—40-FC) and its effects on plant physiology, as well as the hormonal crosstalk between the leaves and SAB. TE caused a 49% increase in WW eucalypt growth, but not to plants under 40-FC. Estimated dose for the greatest stimulatory effect on WW eucalypt plants is 202 g a.i. ha−1. TE did not cause an increase in the plants' photosynthetic characteristics up to 15 days after application (DAA), suggesting a later increase in the eucalypt's primary metabolism. Conversely to what have been reported for monocot crops, TE caused a fivefold increase in leaf GA1 as a short-term effect (05 DAA), but significantly decreased SAB-GA1 concentration. Leaf concentrations of indole-3-acetic acid, salicylic acid, abscisic acid and N6-isopentenyladenine also increased. TE caused changes in both 13-hydroxylated (GA20, GA1 and GA8) and non-13-hydroxylated (GA9, GA4 and GA34) GA metabolic pathways in an organ-specific manner. Our results provide information to support the use of this plant growth regulator in eucalyptus plantations, as well as insights into the hormonal crosstalk between leaves and SAB in response to TE. [ABSTRACT FROM AUTHOR]

Phonolite rock powder is an alternative to potassium fertilizer, having applicable K and Na content among rocks, as well as others nutrients (e.g. Ca, S and Si). The study tested the effects of replacing KCl with phonolite rock powder on tree growth, nutrition, and nutrient cycling in a Eucalyptus stand. We compared four top dressing fertilization treatments: PHO (91.7 kg ha− 1 of K and 47.5 kg ha− 1 of Na, applied via phonolite); SOD (54.2 kg ha− 1 Na, applied via NaCl); KCl (91.7 kg ha− 1 of K), and Control (no top dressing fertilization); where KCl and SOD present equivalent molar amount (2.33 kmol). Leaf K concentrations were elevated in the KCl treatment and leaf Na concentrations were elevated in the SOD treatment. Leaf K and Na concentrations in the phonolite rock powder treatment were similar to or lower than those in the KCl and SOD treatments. There were no differences among treatments in tree growth, volume, and aboveground biomass, probably due to a prolonged drought, during which precipitation was 27% below and the average temperature was 2.3ºC above the local historical average. Trees fertilized with KCl had the highest K deposition in litterfall, those fertilized with NaCl had the highest Na deposition, and phonolite rock powder fertilization was intermediate for both elements. We conclude that despite the use of phonolite did not significantly enhance the growth of eucalyptus plants, its application as a fertilizer yielded comparable leaf concentration, stem volume, and aerial biomass to that achieved with KCl, and in certain instances, even surpassed the results obtained with NaCl fertilization proving it applicability when compared to traditional sources, such as KCl. [ABSTRACT FROM AUTHOR]

Terrestrial vegetation emits substantial amounts of highly reactive isoprene, significantly impacting atmospheric chemistry and climate change. Both atmospheric carbon dioxide (CO2) concentration and temperature can influence plant isoprene emissions; however, whether these factors have a synergistic effect remains unclear, particularly for tropical/subtropical plants. In this study, we conducted in-situ controlled experiments on Eucalyptus urophylla, a representative tropical/subtropical species, to investigate the seasonal variation in the response of isoprene emissions to CO2 concentrations (ISOP-CO2 response) and to identify potential controlling factors. The results showed that high CO2 exerts a nearly linear inhibitory effect on isoprene emissions, as indicated by the slope of the ISOP-CO2 response curve. This inhibitory effect exhibited evident seasonal changes, with stronger suppression during cooler seasons and weaker suppression during warmer seasons. This finding contrasts with the default ISOP-CO2 response in the MEGAN model, which ignored seasonal variation. Further analysis showed a significant correlation between the slope of the ISOP-CO2 response curve and growth temperature from the past 10 days, indicating that these metrics are effective indicators for predicting seasonal changes. Our findings reveal a synergistic mechanism between temperature and CO2 concentration effects on isoprene emissions. By coupling the effects of growth temperature with the ISOP-CO2 response, this mechanism can be integrated into models to provide more accurate predictions of future isoprene emissions, reducing prediction biases, especially during cooler seasons. [ABSTRACT FROM AUTHOR]

Introduction: Parashorea chinensis Wang Hsie (Pc) is an endangered tree species endemic to tropical and subtropical China. However, the acidic red soil areas where it is distributed generally face nutrient limitation. The study of the effects of mixed planting on soil biogeochemical processes contributes to the sustainable management and conservation of Pc. Methods: We selected pure and mixed stands of Pc and collected its rhizosphere and bulk soil samples to clarify the effect of mixed planting on the soil microbial community and the nutrient status. Results: The results showed that (1) All stands were strongly acidic phosphorus-deficient soils (pH <4.0, available phosphorus <10.0 mg-kg 1). There was a significant rhizosphere aggregation effect for soil organic C, total and available N and K, microbial biomass, and inorganic P fraction. (2) The mixed planting significantly increased the soil water content, organic C, available nutrients, the activities of ß-1,4-glucosidase and urease, and microbial biomass. The inorganic P fractions are more influenced by rhizosphere, while organic P fractions are more influenced by tree species composition. (3) Fungi and their ecological functions are more susceptible to tree species than bacteria are, and have higher community compositional complexity and a-diversity in mixed plantations. And mixed planting can improve network complexity among key microorganisms. (4) The correlation between soil microorganisms and environmental factors was significantly higher in mixed forests than in pure forests. Soil organic C, available N and P, microbial biomass C and N, ß-1,4-glucosidase, and stable P fractions were the key environmental factors driving changes in fungal and bacterial communities. Conclusion: In conclusion, the mixed planting patterns are more advantageous than pure plantations in improving soil physicochemical properties, enhancing nutrient effectiveness, and promoting microbial activities and diversity, especially Pc mixed with Eucalyptus grandis x E. urophylla is more conducive to soil improvement and sustainable management, which provides practical references for relocation protection of endangered tree species and species selection and soil fertility management in mixed planting. In addition, the study highlighted the key role of rhizosphere microenvironment in soil nutrient cycling and microbial community structure, which provides new perspectives for a deeper understanding of soil-microbe-plant interaction mechanisms. [ABSTRACT FROM AUTHOR]

Eucalyptus has become one of the most widely planted species in tropical and subtropical regions in China, with important economic, ecological, and social values. However, it is currently unclear how climate change will affect different Eucalyptus species. Therefore, it is urgent to investigate the potential distribution and dynamics of Eucalyptus under current and future climate scenarios. In this study, we analyzed the potential distribution patterns of the three main Eucalyptus species (Eucalyptus grandis, Eucalyptus urophylla, and Eucalyptus tereticornis) under current and future climatic conditions (2041-2060 and 2061-2080) using the optimized MaxEnt model, which integrates a variety of environmental data including climate, topography, soil, and human influence. We also identified the main factors affecting the potential distributions of the three main Eucalyptus species. Themodel indicated that E. grandis exhibited heightened sensitivity to the mean temperature of the coldest quarter (7.0-20.0 °C) and annual mean temperature (11.9-24.2 °C), whereas E. urophylla displayed heightened sensitivity to precipitation of the warmest quarter (272-1694 mm) and annual precipitation (812-2624mm). Conversely, E. tereticornis demonstrated heightened sensitivity to annual mean temperature (12.7-24.5 °C) and temperature seasonality (63.8-598.9). Under the current climate, E. tereticornis had the widest suitable distribution area (124.91 × 104 km²), followed by E. grandis (124.89 × 104 km²) and E. urophylla (119.81 × 104 km²). Under future climate change scenarios, the suitable ranges of E. grandis, E. urophylla and E. tereticornis will continue to expand. This study highlights the importance of climate change in Eucalyptus distribution and provides quantified potential distribution maps for three Eucalyptus species under current and future climate conditions in China. This research offers valuable scientific insights pertinent to the management and rational site selection for Eucalyptus plantations. [ABSTRACT FROM AUTHOR]

Background: As an efficient and high-quality additive in agriculture and forestry production, silicon (Si) plays an important role in alleviating heavy metal stress and improving plant growth. However, the alleviating effect of aluminum (Al) toxicity by Si in Eucalyptus is still incomplete. Results: Here, a study was conducted using two Al concentrations (0 and 4.5 mM) with four Si concentrations (0, 0.5, 1, and 1.5 mM) to investigate plant growth, tolerance and antioxidant defense system in four Eucalyptus species (Eucalyptus tereticornis, Eucalyptus urophylla, Eucalyptus grandis, and Eucalyptus urophylla × Eucalyptus grandis). The results showed that the stress induced by 4.5 mM Al increased oxidative damage, disturbed the balance of enzymatic and non-enzymatic antioxidant systems, and negatively affected plant growth and tolerance quality in the four Eucalyptus species. However, the addition of 0.5 mM and 1 mM Si alleviated the effects of Al toxicity on plant growth and improved plant growth quality by strengthening stress tolerance. Besides, adding Si significantly facilitated the synergistic action of enzymatic and non-enzymatic antioxidant defenses, increased the removal of reactive oxygen species, reduced lipid peroxidation, and oxidative stress, and promoted the phytoremediation rate of the four Eucalyptus species by 18.7 ~ 34.8% compared to that in the absence of Si. Conclusions: Silicon can alleviate the effect of Al toxicity by enhancing the antioxidant capacity and improving plant growth and tolerance quality. Hence, the application of Si is an effective method for the phytoremediation of Eucalyptus plantations in southern China. [ABSTRACT FROM AUTHOR]

Eucalyptus globulus Labill., is a recognized multipurpose tree, which stands out not only for the valuable qualities of its wood but also for the medicinal applications of the essential oil extracted from its leaves. In this study, we implemented an integrated strategy comprising genomic and phenomic approaches to predict foliar essential oil content, stem quality, and growthrelated traits within a 9-year-old breeding population of E. globulus. The strategy involved evaluating Uni/Multi-trait deep learning (DL) models by incorporating genomic data related to single nucleotide polymorphisms (SNPs) and haplotypes, as well as the phenomic data from leaf near-infrared (NIR) spectroscopy. Our results showed that essential oil content (oil yield) ranged from 0.01 to 1.69% v/fw and had no significant correlation with any growth-related traits. This suggests that selection solely based on growth-related traits did n The emphases (colored text) from revisions were removed throughout the article. Confirm that this change is fine. ot influence the essential oil content. Genomic heritability estimates ranged from 0.25 (diameter at breast height (DBH) and oil yield) to 0.71 (DBH and stem straightness (ST)), while pedigree-based heritability exhibited a broader range, from 0.05 to 0.88. Notably, oil yield was found to be moderate to highly heritable, with genomic values ranging from 0.25 to 0.60, alongside a pedigree-based estimate of 0.48. The DL prediction models consistently achieved higher prediction accuracy (PA) values with a Multi-trait approach for most traits analyzed, including oil yield (0.699), tree height (0.772), DBH (0.745), slenderness coefficient (0.616), stem volume (0.757), and ST (0.764). The Uni-trait approach achieved superior PA values solely for branching quality (0.861). NIR spectral absorbance was the best omics data for CNN or MLP models with a Multi-trait approach. These results highlight considerable genetic variation within the Eucalyptus progeny trial, particularly regarding oil production. Our results contribute significantly to understanding omics-assisted deep learning models as a breeding strategy to improve growth-related traits and optimize essential oil production in this species. [ABSTRACT FROM AUTHOR]

Spectral and texture features play important roles in plantation leaf area index (LAI) estimation, and their combination may enhance LAI inversion accuracy. Furthermore, research on the impact of different machine learning (ML) models on their hyperparameter combinations and splitting ratios remains challenging. In our study, experiments based on spectral and textural features of GF-6 WFV data were conducted on Eucalyptus grandis plantation forests in Huangmian Town, Guangxi, China. ML methods such as multiple stepwise regression (MSR), random forest (RF), back-propagation neural network (BPNN), and support vector regression (SVR) were mainly utilized to perform model hyper-parameter tuning and split-ratio analysis in order to estimate the LAI. The results of the study showed that spectral and gray level co-occurrence matrix (GLCM) texture features were very sensitive to changes in Eucalyptus grandis LAI. The accuracy of combining the two was 10% higher than when they were not combined. Furthermore, it was found that the nonlinear methods (RF, BPNN, and SVR) outperformed the linear method (MSR), with the average 2 Rmax of the nonlinear model being 26% higher than that of the linear model, and the RMSE value being 29% lower than that of the linear model. In addition, by analyzing different combinations of features, model hyperparameter fine-tuning, and splitting ratios in the nonlinear model, it was found that the splitting ratios of different combinations of model hyperparameters have a great impact on the accuracy of the model. A total of 12 out of 21 data sets showed high accuracy and stability at a split ratio of 8.5:1.5 (ratio of 0.85), with the best-performing RF model differing from the lowest by 91% for 2 max R and 39% for 2 Rstd. Combining spectral and texture features provides highly accurate inversion data. Model hyper-parameter fine-tuning and segmental scale tuning can facilitate the application of inversion data to fully utilize the optimal performance of the ML model. [ABSTRACT FROM AUTHOR]

Eucalyptus is an important plantation tree with a high economic value in China. The tree contributes significantly to China's timber production. The stable and efficient Eucalyptus regeneration system and genetic transformation system are of great significance for exploring the regulatory function and possible genetic breeding capacity of important genes in the species. However, as a woody plant, Eucalyptus has problems, such as a long generation cycle, strong specificity of the regeneration system, and a low genetic conversion rate, which seriously limit the rapid development of Eucalyptus genetics and breeding programs. The present review summarizes the status of research on Eucalyptus regeneration and genetic transformation, with a focus on the effects of explants, media, plant growth regulators (PGRs), and concentrations in the Eucalyptus regeneration process. In addition, the effects of genotype, Agrobacterium, antibiotics, preculture, and co-culture on the genetic transformation efficiency of Eucalyptus are discussed. Furthermore, the study also summarizes the problems encountered in Eucalyptus regeneration and genetic transformation, with reference to previous studies, and it outlines future developments and prospects. The aim was to provide a reference for solving the problems of genetic instability and the low transformation efficiency of eucalyptus, and to establish an efficient and stable eucalyptus regeneration and transformation system to accelerate the process of its genetic improvement. [ABSTRACT FROM AUTHOR]

Mixed tree plantations containing nitrogen (N2)-fixing species have the potential to enhance C sequestration, soil biodiversity and forest productivity. Here, we investigated the impact of Acacia mangium and Eucalyptus urophilla x E. grandis mixed plantations in the Congolese coastal plains on soil mycobiota community structure and diversity by ITS metabarcoding sequencing and bioinformatic analysis. Higher Faith's phylogenetic diversity and Evenness' was found in Eucalyptus monoculture relative to stands containing Acacia. Differences in beta diversity were found among Eucalyptus and Acacia monoculture, and mixed-species stands highlight the effects of plant species on fungal community structure. Ascomycota, Basidiomycota and Rozellomycota phyla were predominant in all stands, with both Dikarya (Ascomycota and Basidiomycota) accounting for more than 70% in all stands. Correlation analysis revealed that sulfur (S) was the most correlated soil attribute with the three predominant phyla but also with Mucoromycota and Calcarisporiellomycota phyla, although mostly negatively correlated (4 out of 5). Phosphorus was mostly positively correlated to soil attributes (3 out of 4) and nitrogen was correlated twice, positively and negatively. Distance-based redundancy analysis revealed a positive correlation of nitrogen (p-value = 0.0019, contribution = 22%) and phosphorus (p-value = 0.0017, contribution = 19%) with soil mycobiota. A high prevalence of generalists (28% to 38%) than specialists (9% to 24%) were found among the different sites. In stands containing Acacia (pure and mixed species) the soil mycobiota harbor the prevalence of generalist strategies with the potential to withstand environmental stresses and utilize a higher number of resources against specialists in Eucalyptus stands. Stronger positive correlation between soil attributes and main fungal taxa, higher generalists' strategies and lower Faith's phylogenetic diversity and Evenness were reported in stands containing Acacia. This highlights the potential of mixed-species in preserving community stability following environmental disturbances and increasing the number of resources confirming their important ecological role in boosting the resilience of the forest ecosystems to climate and land-use (plant species as shown by PCA analysis) changes. [ABSTRACT FROM AUTHOR]

Key message: Accurate volume estimation in Eucalyptus plantation stands was achieved by a linear model using SPOT and Landsat multispectral imagery, specifically texture indices and pixel-scale NDVI time integrals, which reflect the local plantation growth history. Spatial modelling techniques such as Kriging with External Drift and Generalized Additive Model slightly improved predictions by accounting for spatial correlation of volume between sample points. Context: Forest inventories are widely used to estimate stand production. To capture the inherent spatial variability within stands, spatial modelling techniques such as Kriging with External Drift (KED) and the generalized additive model (GAM) have emerged. These models incorporate information on spatial correlation and auxiliary variables that can be obtained from satellite imagery. Aims: Our study explored the use of reflectance data from SPOT and Landsat multispectral imagery. We focused on texture indices and temporal integration of vegetation indices as auxiliary variables in KED and GAM to predict stem volume of fast-growing Eucalyptus sp. plantations in Brazil. Methods: The components extracted from the high-resolution SPOT-6 image included spectral band values, band ratio metrics, key vegetation indices (NDVI, SAVI, and ARVI), texture measurements, and indices derived from texture analysis. Additionally, we included the accumulated NDVI time series acquired from Landsat 5, 7, and 8 satellites between the planting date and the forest inventory measurement date. Results: The best linear model of stem volume using remotely sensed predictors gave an R-squared value of 0.95 and a Root Mean Square Error (RMSE) of 12.44 m3/ha. The R-squared increased to 0.96 and the RMSE decreased to 10.6 m3/ha when the same predictors were included as auxiliary variables in the KED and GAM spatial models. Conclusion: The linear model using remotely sensed predictors contributed most to volume prediction, but the addition of spatial coordinates in the KED and GAM spatial models improved local volume predictions. [ABSTRACT FROM AUTHOR]

Introduction: Boron (B) is critical for plant growth, yet its movement in soil is often hindered by leaching and adsorption, leading to deficiencies. Tackling these issues is essential for boosting agricultural productivity, especially in plants like Eucalyptus with high B needs. This paper aims to address these challenges by evaluating B-doped biochar composites (biochar-B) that enhance B distribution and stability in the soil, focusing on Eucalyptus grandis cultivation in two distinct oxisol types. Materials and methods: Biochar-B composites were created using shrimp carcass (FSC), chicken manure (FCM) and sewage sludge (FSS), combined with boric acid (BA) and borax (BX), and pyrolyzed at 300 °C and 550 °C. The experimental design was a completely randomized design (CRD) with three replicates. Results: Fourier transform infrared spectroscopy (FTIR) analysis confirmed successful B integration and interaction with organic matrices, highlighting functional groups responsible for composite properties. This facilitated the development of highly predictive partial least squares (PLS) regression models (R2pred ~ 0.8). The FSC-BA composite at 300 °C showed notable thermal stability, B retention and availability, enhancing B release kinetics. Discussion: These findings emphasize the importance of considering the soluble B rate in composite applications for Eucalyptus cultivation. The use of these composites provides a sustainable method for gradual B release, potentially outperforming conventional fertilization techniques. This approach may lead to improved plant growth and productivity. Further field investigations are recommended in order to validate these findings and refine sustainable fertilization strategies; thus, benefiting a range of crops. [ABSTRACT FROM AUTHOR]

Among the storage insects, Callosobruchus maculatus is reported to cause significant damage to legumes, resulting in 5–10% postharvest loss. Conventionally used synthetic chemical pesticides raised significant health concerns among consumers. The present study aimed to develop a eucalyptus essential oil-based nanoemulsion (EO-NE) and test its efficacy against C. maculatus. The developed EO-NE with a surfactant: oil ratio of 5 was kinetically stable, with no phase separation, creaming, or crystallization after 60 days. EO-NE droplets were spherical, with average droplet size and polydispersity index of 17.16 nm and 0.313, respectively. Increased adhesiveness and wettability of EO-NE are correlated with optimal viscosity (53.51cPs) and reduced contact angle (45°). FTIR analysis assured efficient oil trapping inside nanoemulsions without significant changes in functional groups. The effective repellence of C. maculatus was validated by negative excess proportion index values. According to the data, the EO-NE concentration and exposure period are directly proportional to insect mortality. These findings imply that EO-NE may be employed as a green insecticide to manage C. maculatus infestations in grain-storage facilities. [ABSTRACT FROM AUTHOR]

Changes in vapour pressure deficit can lead to the depletion and replenishment of stem water pools to buffer water potential variations in the xylem. Yet, the precise velocity at which stem water pools track environmental cues remains poorly explored. Nine eucalyptus seedlings grown in a glasshouse experienced high-frequency environmental oscillations and their stem radial variations (ΔR) were monitored at a 30-s temporal resolution in upper and lower stem locations and on the bark and xylem. The stem ΔR response to vapour pressure deficit changes was nearly instantaneous (<1 min), while temperature lagged behind stem ΔR. No temporal differences in the stem ΔR response were observed between locations. Punctual gravimetric measurements confirmed the synchrony between transpiration and stem ΔR dynamics. These results indicate (i) that stem-stored water can respond to the atmospheric evaporative demand much faster than commonly assumed and (ii) that the origin of the water released to the transpiration stream seems critical in determining time lags in stem water pool dynamics. Near-zero time lags may be explained by the high elasticity of eucalyptus woody tissues and the predominant water use from the xylem, circumventing the hydraulic radial barriers to water flow from/to the outer tissues. [ABSTRACT FROM AUTHOR]

Summary: A wood from a late Middle Eocene in-situ fossil forest in northern Peru shows affinity with Qualea (Vochysiaceae), a genus of South American lowland tropical trees, based on features including vestured pits, aliform-confluent to banded paratracheal parenchyma, and homocellular rays. Additional features suggest adaptation to dry conditions. The fossil is named as a new species within Qualeoxylon (Q. lafila). Vochysiaceae and sister-group Myrtaceae share features unique to Myrtales (vestured pits, intraxylary phloem) or common in the order (vessels generally solitary and in >1 diameter class, heterocellular rays) but in other ways are clearly differentiated. Vochysiaceae has narrow to very wide vessels with elaborated axial parenchyma and lacks most characters considered less specialized such as scalariform perforations. Myrtaceae generally has vessels with vasicentric tracheids, usually exclusively solitary, very narrow to wide, and often diagonally arranged, and includes taxa with less to more specialized features. Woods with elaborated paratracheal parenchyma and vessels wide to very wide occur in wet tropical forest environments in both families Erisma , Vochysia and Qualea / Ruizterania (Vochysiaceae) in the Neotropics and Syzygium (Myrtaceae) in the Asian tropics. The Eucalyptus spp. dominating open forests in Australia have typical myrtaceous features (including vasicentric tracheids) plus homocellular rays, whereas the eucalypt clade Angophora + Corymbia , occurring mainly in the northern, monsoonal regions of Australia, has both vasicentric tracheids and aliform to banded axial parenchyma. The fossil is an early record for Vochysiaceae and adds to indications that Vochysiaceae and sister-group Myrtaceae showed significant diversification by the late Paleogene. [ABSTRACT FROM AUTHOR]

Simple Summary: This study analyzed the effect of forest plantations on the taxonomic and functional diversity of dung beetles in comparison to natural forests in southern Ecuador. The results indicated a greater abundance of generalist species in the plantations, likely due to their high level of adaptation to disturbances and their presence in nearby forests. This could be attributed to the proximity of these areas to urban zones, which may influence the dung beetle community, as their primary food source depends on mammals. However, this study highlights the lack of information on this topic in the Neotropics, particularly in Ecuador, suggesting that further research is needed to compare and validate these findings. This study sheds light on the complex relationship between land use, biodiversity, and the functional traits of dung beetles in Ecuador. The results indicate that the richness and abundance of dung beetles vary across different land uses and regions, with forests generally having a positive impact, while eucalyptus and pine plantations have a negative effect in certain areas. Specific indicator species, such as Homocopris buckleyi for forest areas and Onthophagus curvicornis for eucalyptus plantations, were identified. This study also found that functional diversity analysis, based on morphological traits, revealed that certain traits, such as biomass, pronotum width, head width, and elytra length, were significant contributors to differences in dung beetle communities across various land uses and regions. This study highlights the potential conservation value of certain modified habitats and emphasizes the importance of considering both taxonomic and functional diversity when assessing the impact of land use on the ecosystem services provided by dung beetles. It underscores the potential value of plantations as refuges for dung beetle communities and the need for long-term assessments to better understand biodiversity changes over time. [ABSTRACT FROM AUTHOR]

Whitefly, Bemisia tabaci, nymphs and sucking sap adults, is one of the most damaging pests of potato, Solanum tuberosum. Excessive use of pesticides causes environmental pollution and the death of beneficial insects, so it is necessary to search for safer controlling alternatives. An experiment was carried out during seasons 2020–2021 and 2021–2022, under field conditions in Egypt. The objective of this study was to identify the main constituent compounds of peppermint and eucalyptus essential oils prepare coarse emulsion (CE) and nanoemulsion (NE) of both peppermint and eucalyptus essential oils and evaluate their efficiency against the whitefly, B. tabaci, in potato cultivars and the effect of these emulsions on the chemical components of potato leaves. The results revealed that the toxicity of the emulsions decreased with increasing time after spraying. The second spray which took place at a 10-day interval was more effective than the first spray. During the season of 2021, three days following the second spray, the tested emulsions' toxicity was highly effective. The reduction percentages of nymph for peppermint coarse emulsion (PCE), peppermint nanoemulsion (PNE), eucalyptus coarse emulsion (ECE), eucalyptus nanoemulsion (ENE) and imidacloprid were 82.64, 84.14, 73.26, 72.72 and 89.03, but they were 78.58, 83.27, 77.85, 69.97 and 89.26 compared with 2022. A moderately positive correlation was identified between temperature, specific humidity, wind speed and the effectiveness of the emulsions. This indicates that higher levels of temperature, humidity and wind speed were associated with increased efficacy of the emulsions. The study of the phytochemicals (total soluble protein, total carbohydrate, total phenolic contents and peroxidase activity). PCE and ECE achieved a slight decrease in protein levels. Also, ECE increased total plant carbohydrates. All treatments did not affect the phenolic compounds of potato leaf plants except ENE, which caused an increase in phenolic compounds. All treatments decreased the nitrogen plants' contents, while PCE, PNE, and ENE increased the potassium content. All treatments increase the activity of peroxidase (POX) compared with untreated plants. The formulations PNE and ENE might be an interesting alternative for integrated pest management of B. tabaci nymphs. [ABSTRACT FROM AUTHOR]

The growing demand for raw materials in the forestry sector and the imperative to conserve native forests have spurred the expansion of forest areas planted globally, particularly in Brazil. Eucalyptus stands out as the primary genus employed in the Brazilian forestry industry. Addressing the need for new clones due to expanding exploitation and changing climate conditions poses a considerable challenge. The evaluation of genotypes in multi-environment trials (MET) is complicated by their varying behavior. Factor analytic mixed models (FAMM) are presently employed for MET analyses, enabling the modeling of genotype-by-environment interactions without a substantial increase in parameters. However, existing tools for assessing genotype stability and adaptability within FAMM are unsuitable for scenarios involving a large number of Eucalyptus clones, typical in intermediate clonal testing stages. To address this gap, a methodology for clonal selection in Eucalyptus is required. FAMM offers a way to summarize clone responses across environments through scores. Utilizing the genotype-ideotype (GI) distance based on these scores facilitates the ranking of clones. This study aims to propose and assess the use of genotype-ideotype distance in conjunction with FAMM for selecting Eucalyptus clones in multi-environment trials. The combined use of FAMM and genotype-ideotype distance enables the ranking of clones based on broad adaptability. This approach balances the simplicity of a single parameter's interpretability with the capability to handle a large number of clones effectively. [ABSTRACT FROM AUTHOR]

The frequency, duration, and size of wildfires have been increasing, and the inhalation of wildfire smoke particles poses a significant risk to human health. Epidemiological studies have shown that wildfire smoke exposure is positively associated with cognitive and neurological dysfunctions. However, there is a significant gap in knowledge on how wildfire smoke exposure can affect the blood–brain barrier and cause molecular and cellular changes in the brain. Our study aims to determine the acute effect of smoldering eucalyptus wood smoke extract (WSE) on brain endothelial cells for potential neurotoxicity in vitro. Primary human brain microvascular endothelial cells (HBMEC) and immortalized human brain endothelial cell line (hCMEC/D3) were treated with different doses of WSE for 24 h. WSE treatment resulted in a dose-dependent increase in IL-8 in both HBMEC and hCMEC/D3. RNA-seq analyses showed a dose-dependent upregulation of genes involved in aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2-related factor 2 (NRF2) pathways and a decrease in tight junction markers in both HBMEC and hCMEC/D3. When comparing untreated controls, RNA-seq analyses showed that HBMEC have a higher expression of tight junction markers compared to hCMEC/D3. In summary, our study found that 24 h WSE treatment increases IL-8 production dose-dependently and decreases tight junction markers in both HBMEC and hCMEC/D3 that may be mediated through the AhR and NRF2 pathways, and HBMEC could be a better in vitro model for studying the effect of wood smoke extract or particles on brain endothelial cells. [ABSTRACT FROM AUTHOR]

This study investigates the effectiveness of various chemical methods, both ultrasound-assisted and non-assisted, for extracting cellulose from banana pseudostem (BPS) waste, comparing the results with commercial pine and eucalyptus cellulose fibers. Delignification treatments with NaOH (25% and 30%) and H2O2 (8%) were evaluated, applied with both conventional and focused sonication. Ultrasound-assisted methods, particularly with NaOH, achieved cellulose percentages as high as 99.5%. X-ray diffraction (XRD) analysis revealed that NaOH treatments significantly increased the cellulose crystallinity index, reaching up to 67.9%, surpassing commercial fibers. Scanning electron microscopy (SEM) results showed that NaOH treatments, especially at 30%, improved fiber morphology and exposure. Thermogravimetric analysis (TGA) indicated that methods using NaOH and focused sonication enhanced the thermal stability of the cellulose. Compared to commercial fibers, some samples obtained with the proposed methods demonstrated higher purity, yield, and thermal stability, highlighting the effectiveness of ultrasound-assisted and NaOH methods. [ABSTRACT FROM AUTHOR]

Leaf area varies within and between species, and previous work has linked this variation to environment and evolutionary history. However, many previous studies fail to examine both these factors and often are data‐limited.To address this, our study developed a new workflow using machine learning to automate the extraction of leaf area from herbarium collections of Australian eucalypts (Eucalyptus, Angophora and Corymbia). This dataset included 136,599 measurements, expanding existing data on this taxon's leaf area by roughly 50‐fold. Our methods were validated using field standard metrics of accuracy, and comparisons to manual measurements both from the present study and existing datasets.With this dataset for the eucalypt clade, we observed positive relationships between leaf area and mean annual temperature and precipitation similar to those reported for the global flora. However, these relationships were not consistently observed within species, potentially due to gene flow suppressing local adaptation. When we examined these relationships at different phylogenetic levels, the slope of trait–climate associations within lineages converged towards the overall eucalypt slope at shallow phylogenetic scales (5–12 MY), suggesting that effects of gene flow relax just above the species level.The strengthening of trait–climate correlations at evolutionary scales just beyond the intraspecific level may represent a widespread phenomenon across various traits and taxa. Future studies can unveil these relationships with the larger sample sizes of new trait datasets generated through machine learning.Synthesis. Using machine learning, researchers are able to confirm current positive global relationships between leaf area and mean annual temperature and precipitation. Additionally, they were able to take this a step further and examine how it changes across time. Here they saw that at roughly 5–12 million years ago in the phylogenetic tree, the trait–climate slope begins to show significantly less variation. Overall, the study shows the potential of machine learning in ecology, with exciting new potential findings with its use. [ABSTRACT FROM AUTHOR]

Variability in Eucalyptus wood density and chemical properties is crucial to understanding important factors for the forest-based industry, such as sampling methods and wood suitability as raw material. This study aimed to evaluate the basic density and chemical composition of the radial positions of young wood from the Eucalyptus urophylla clone grown under different precipitation levels. Trees from E. urophylla clonal plantations were collected in Inhambupe, Jandaíra and Itanagra, Bahia State, Brazil. Trees' basic density and chemical composition (total extractive, lignin, hemicelluloses and α-cellulose) were determined based on the basal log of each tree, at four radial positions (1, 2, 3 and 4). It was found that the basic density and α-cellulose of wood are influenced by the cambial age and the site rainfall. There was greater increase in sections close to the bark (positions 1 and 4) and in more humid environments (sites Itanagra and Jandaríra). This finding highlights the association between wood basic density and chemical composition, mainly in the holocellulose content. [ABSTRACT FROM AUTHOR]

SUMMARY: Xylan is one of the major hemicelluloses in plant cell walls and its xylosyl backbone is often decorated at O‐2 with glucuronic acid (GlcA) and/or methylglucuronic acid (MeGlcA) residues. The GlcA/MeGlcA side chains may be further substituted with 2‐O‐arabinopyranose (Arap) or 2‐O‐galactopyranose (Gal) residues in some plant species, but the enzymes responsible for these substitutions remain unknown. During our endeavor to investigate the enzymatic activities of Arabidopsis MUR3‐clade members of the GT47 glycosyltransferase family, we found that one of them was able to transfer Arap from UDP‐Arap onto O‐2 of GlcA side chains of xylan, and thus it was named xylan 2‐O‐arabinopyranosyltransferase 1 (AtXAPT1). The function of AtXAPT1 was verified in planta by its T‐DNA knockout mutation showing a loss of the Arap substitution on xylan GlcA side chains. Further biochemical characterization of XAPT close homologs from other plant species demonstrated that while the poplar ones had the same catalytic activity as AtXAPT1, those from Eucalyptus, lemon‐scented gum, sea apple, 'Ohi'a lehua, duckweed and purple yam were capable of catalyzing both 2‐O‐Arap and 2‐O‐Gal substitutions of xylan GlcA side chains albeit with differential activities. Sequential reactions with XAPTs and glucuronoxylan methyltransferase 3 (GXM3) showed that XAPTs acted poorly on MeGlcA side chains, whereas GXM3 could efficiently methylate arabinosylated or galactosylated GlcA side chains of xylan. Furthermore, molecular docking and site‐directed mutagenesis analyses of Eucalyptus XAPT1 revealed critical roles of several amino acid residues at the putative active site in its activity. Together, these findings establish that XAPTs residing in the MUR3 clade of family GT47 are responsible for 2‐O‐arabinopyranosylation and 2‐O‐galactosylation of GlcA side chains of xylan. Significance Statement: Xylan is one of the major hemicelluloses in plant cell walls and its GlcA side chains may be further substituted with 2‐O‐Arap or 2‐O‐Gal residues. We have uncovered the functions of a subgroup of MUR3‐clade GT47 members in catalyzing the transfer of 2‐O‐Arap and/or 2‐O‐Gal onto GlcA side chains of xylan, which expands our understanding of glycosyltransferases involved in xylan substitutions. [ABSTRACT FROM AUTHOR]

Eucalyptus spp. in plantations are negatively affected by canker and wilt diseases caused by several species of Ceratocystis , particularly those in the Latin American Clade (LAC). Ceratocystis eucalypticola and Ceratocystis manginecans are of particular concern where disease epidemics are reported globally, with recent outbreaks emerging in South African and Indonesian Eucalyptus plantations. Consequently, a rapid screening protocol is required for these pathogens. In this study, a high-resolution melting curve analysis (HRMA) was developed to detect C. eucalypticola and C. manginecans that bypasses time-consuming isolation and post-PCR procedures. Primers targeting a 172 bp region of the cerato-platanin (CP) gene were designed. Using these primers, the accuracy of HRMA to detect and distinguish between these two LAC species was assessed using pure fungal DNA, and DNA extracted directly from Eucalyptus samples naturally infected with C. eucalypticola. The assay accurately detected the presence of C. eucalypticola and C. manginecans and quantifies their DNA, both from cultures, and directly from wood samples. HRMA further differentiated these two species from all other tested LAC individuals. This assay was also able to detect the presence of all the tested LAC species and distinguish seven of these, including C. fimbriata, to species level. Ceratocystis polyconidia was the only non-LAC off-target species detected. Based on these results, the developed assay can be used to rapidly identify C. eucalypticola and C. manginecans directly from infected plant material or fungal cultures, with the potential to also screen for several other LAC species. • Rapid diagnostic assay to detect and differentiate C. eucalypticola and C. manginecans in the form of a qPCR-HRMA assay. • The assay can identify C. eucalypticola and C. manginecans from fungal cultures or directly from infected plant material. • The assay shows the potential to be used for other species in the LAC. [ABSTRACT FROM AUTHOR]

Calonectria leaf blight (CLB) is one of the best-known diseases of Eucalyptus spp., particularly in Asia and South America. Recently, typical symptoms of leaf and shoot blight caused by Calonectria spp. Were observed in a Eucalyptus plantation in the YunNan Province of southwestern China. Isolations were made from diseased leaves and top soil collected below the diseased trees to determine the causal agent of the disease and to consider the distribution characteristics of the Calonectria species. This resulted in 417 isolates, of which 228 were from leaves and 189 were from soil. Based on comparisons of DNA sequences for the act (actin), cmdA (calmodulin), his3 (histone H3), rpb2 (the second largest subunit of RNA polymerase), tef1 (translation elongation factor 1-alpha) and tub2 (β-tubulin) gene regions, as well as morphological characteristics, 11 Calonectria species were identified. These included Calonectria aciculata (0.7 %), Ca. colhounii (1.2 %), Ca. eucalypti (10.6 %) and Ca. honghensis (43.2 %) in the Ca. colhounii species complex, and Ca. aconidialis (15.3 %), Ca. asiatica (9.8 %), Ca. hongkongensis (1.0 %), Ca. ilicicola (6.0 %), Ca. kyotensis (0.5 %), and Ca. yunnanensis (11.3 %) in the Ca. kyotensis species complex. In addition, a novel species, accounting for 0.5 % of the isolates, was discovered and is described here as Ca. dianii sp. nov. in the Ca colhounii species complex. Most (99.1 %) of the isolates collected from the leaves resided in the Ca. colhounii species complex and a majority (95.8 %) of those from the soils were in Ca. kyotensis species complex. These results suggest that Calonectria spp. in the Ca. colhounii species complex infecting leaves might be adapted to that niche and that those in the Ca. kyotensis species complex are better adapted to a soil habitat. Calonectria leaf blight (CLB) is one of the best-known diseases of Eucalyptus spp., particularly in Asia and South America. A large number of Calonectria isolates were obtained from diseased leaves and soil samples collected from below the infected Eucalyptus trees in one plantation in China. A rich Calonectria diversity in the sampled Eucalyptus plantation were revealed. There were clear differences in species diversity and distribution relating to either the leaf or soil environments where they were found. It is becoming increasingly apparent that some species are predominantly soil inhabitants and different to those that cause plant diseases. [ABSTRACT FROM AUTHOR]

Smallholder farmers are increasingly planting eucalyptus trees as an important farm product in many rural areas of Ethiopia including the study area - Gurage Zone. This study analyzed the contribution of eucalyptus trees to rural households' livelihood and factors that influence the share of land allocated to eucalyptus by smallholder farmers in the study area. The study mainly used household survey, key informant interviews as well as Focus Group Discussions to generate the required data for the study. The descriptive analysis indicated that eucalyptus tree is an important farm product as a source of households' energy in addition to other economic and social benefits. In addition to being the most reliable source of finance during times of emergency, it was found to contribute almost 31% of total annual household income. Furthermore, the fraction logit estimation indicated factors such as total household income, household heads' perception towards eucalyptus trees, livestock holdings as well as distance from main roads to be important factors in determining the share of land allocated to eucalyptus trees. We recommend government officials and experts to assist smallholder farmers to use rural land in the most sustainable way by developing and implementing appropriate land use policy. [ABSTRACT FROM AUTHOR]

Silvopastoral systems (SPS) offer both environmental and economic benefits, including climate change mitigation through carbon sequestration. Important features are tree density and animal stock rate. The objective of this study was to evaluate the long-term trajectory of sustainable livestock carrying capacity and carbon budget developing an Agent-Based Model (ABM) for an SPS. The ABM outputs the performance of animal growth, forage, and trees in several scenarios over 10-year periods. Rotational grazing and forestry presence in paddocks allowed the achievement of a balance among forage availability, cattle demand and trees. The model fit very well in predicting Live weight gain and Live weight (LW) for cattle. The average length of fattening cycles was 258 ± 24 days, and an annual yield of LW exported of the system of 98.7 ± 2.6 kg ha−1. A balance of carbon–neutral or marginally positive in beef production was achieved with a ratio of 380 steers at a 606-ha grazing area with 13% forested surface. Estimated carbon emission exhibited an inverse exponential relationship with weight gain. The average emission was 24.9 kg of CO2e per unit of LWG, for an average gain of 0.388 kg animal−1 day−1. The ABM is a valuable tool for understanding the complexity of these systems, generating emergent properties. The results revealed a conflict between the economic-productive and the environmental dimension. So as to achieve a neutral carbon system, it is necessary to maintain a lower number of livestock heads than the property's potential (0.72 vs 0.79 livestock units per hectare). Future research should include economic and other environmental variables in the model. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of tree shading in silvopastoral systems (SPS) on forage production through long-term experiments, as well as to determine the correlation between dendrometric variables of eucalyptus trees and transmission of photosynthetically active radiation (PAR) to establish thereby the optimum forest cover for effective management in these systems. We evaluated four SPSs in São Carlos, SP (21° 57′ 42″ S, 47° 50′ 28″ W, 854 m.) and Campo Grande, MS (20° 24′ 55″ S, 54° 42′ 26″ W, 530 m.), Brazil, considering various factors such as tree age, management, and density. The systems included pastures with eucalyptus (Eucalyptus urograndis) or corymbia (Corymbia citriodora) trees planted in single rows at densities ranging from 83 to 357 trees ha−1. During the rainy season, from October to March, we analyzed the correlation between PAR transmission and relative forage production (forage production in the SPS/forage production in full sun), as well as the correlation between dendrometric variables, such as diameter at breast height, volume and basal area per unit area and PAR transmission. The results showed a linear reduction in production in the SSPs due to the decrease in PAR transmission. The strongest correlation between tree growth and PAR transmission was obtained with the basal area per hectare variable (r = − 0.91). Thus, this study successfully established a linear relationship between basal area per hectare and PAR transmission, providing insights for the implementation of tree thinning management in SPSs to maintain the productive potential of forage plants in the understory of these systems. [ABSTRACT FROM AUTHOR]

Human population growth constantly requires an increase in the production of food and products from the timber industry. To meet this demand, agriculture and planted forests are advancing over natural areas. In view of this, it is necessary to know the effects of land use for different purposes (grain production, pastures, planted forests, fruit production and among other uses) on the genetic diversity of populations of native species. This knowledge can assist in land use planning as well as in the development of conservation strategies for native species. In this study, we evaluated the effect of land use for agriculture (mainly for cereal production) and planted forests on the genetic diversity of Baccharis crispa Spreng. a herb native to South America. To achieve our goals, we compared population genetic data obtained with three molecular markers (microsatellites, inter-simple sequence repeat and isoenzymes) with data on land use for agriculture and planted forests from 15 different locations. Our results showed that regardless of the molecular marker used, the greater the use of land for agriculture and planted forests, the lower was the genetic diversity of B. crispa populations. Baccharis crispa is a semi-perennial species that needs at least one year to reach its reproductive period, which is prevented in agricultural areas due to the land being turned over or dissected with herbicides every 6 months. In the studied regions, the planted forests are of eucalypt and/or pine, which besides being species with a high production of allelopathic substances, produce strong shading and B. crispa is a species that inhabits open grassland that needs a high incidence of sunlight for development. The data obtained in our study can assist in the decision-making to use land in order to reconcile the production of supplies for humanity and for the conservation of nature. [ABSTRACT FROM AUTHOR]

Eucalyptus urophylla S.T. Blake, an important economic tree species, is widely cultivated as a raw material source for pulpwood, veneer plywood, and sawlog timber in southern China. As a tree in multiple environments, tree-breeding programs can assess genotype by environment (G × E) interactions and identify the suitable genotype for a specific environment. G × E interactions related to growth traits and soil factors have not been adequately studied for clones of Eucalyptus urophylla and its hybrids. To examine this important question, trials containing 20 clones of E. urophylla and its hybrids were established at three sites in southern China: Shankou (SK), Tiantang (TT), and Xiniujiao (XNJ). These sites each have different soil conditions but similar geographical and climatic conditions. With the data across nearly eight years, average phenotypic trends and broad sense repeatability (H2) were modeled, G×E interactions between clones and diverse soil environments were estimated, genetic gains of clones were calculated, and the adaptabilities of E. urophylla clones in different soil environments were compared. Average survival trends for clones tended to show a moderate decrease while growth traits tended to show sharp increases with age. At the same age, sites were ordered for average survival and growth traits as TT>SK>XNJ while H2 values for growth traits by site followed the basic order TT>SK>XNJ. The H2 values for growth traits at SK tended to increase at first, platform, and then smooth with age. The H2 values for growth traits at TT were high and stable across ages, and those at XNJ tended to undulate largely at a relatively low level across ages. Genetic correlations for growth traits between any pair of sites tended to increase at first and then decrease. A genetic correlation was strong between SK and TT, intermediate between SK and XNJ, and weak between TT and XNJ. It was concluded that: (1) clones tended to be adapted better to an environment with acidic and loamy soil with a clay content of about 45.6%, the soil depth from the surface to parent material about 1.5 m, and the previous vegetation of Eucalypts. (2) The G×E interactions between clones and sites are weaker if the environmental conditions between the sites are similar, and which are stronger if the environmental conditions between the sites are different. (3) The optimum selection age for clones ranged from 1.5 to 3.5 years old, while the optimum selection growth trait is individual tree volume. [ABSTRACT FROM AUTHOR]

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