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ABSTRACT Climate change and human influence are transforming mountain ecosystems, significantly impacting species distributions and biodiversity. Among these changes, the upward migration of lowland species into mountain regions stands out. This study examines the ecogeographical niche overlap and genetic diversity among three Leucanthemum species distributed along an altitudinal gradient in the Carpathian Mountains: the lowland L. ircutianum (4x), the montane L. rotundifolium (2x) and the alpine L. gaudinii (2x). By genotyping over 600 individuals using SNP analysis, followed by principal coordinate analysis (PCoA), Neighbour‐Net Network and Structure clustering, we reveal not just distinct genetic groups but also hybridisation across all species, suggesting the potential for triple hybrids. Genetic admixture is further supported by environmental background and niche overlap analyses that reveal substantial overlap among species, particularly in line with their vertical distribution. Climate envelope plots indicate a likely reduction in available habitat for mountainous species due to climate change, leading to an increase in competition and an intensification of hybridisation. Anthropogenic influences are further intensifying these hybridisation trends. Among the studied species, L. gaudinii is most at risk of overwhelming hybridisation, whereas L. ircutianum may experience habitat expansion. By providing a comprehensive genetic and ecological overview, our research highlights the significance of hybridisation in biodiversity conservation and the challenges posed by environmental changes and anthropogenic activities in mountain environments. This study not only contributes to the understanding of genetic diversity in the Carpathians but also underscores the broader implications for molecular ecology and conservation strategies in mountain ecosystems. [ABSTRACT FROM AUTHOR]

Introduction: Yam is an important crop for food security in East and West Africa due to its high market value and customer demand. High tuber quality with yield and disease resistance are the main traits for acceptability of yam cultivars across the tropical zone. There has been limited progress in enhancing the production and quality traits of yams, despite the significant socio-economic significance of this crop. Method: To expedite the development of high-quality yam cultivars in Uganda, traits association study was conducted to identify genomic regions associated with key traits such as disease resistance, high yields, and dry matter content. The association mapping was conducted with multi-random mixed linear model (mrMLM) to compute the associations using five genetic models. Results: A total of 16 significant single nucleotide polymorphisms (SNPs) markers were identified to be associated with the traits studied. Gene identification analysis revealed the presence of key putative genes such as Vicilin-like seed storage protein At2g28490 (ARATH)and Growth-regulating factor 1 involved in a variety of functions ranging from storage and gene regulation for disease resistance. Discussion: The results obtained from this work have significant implications for the in-depth analysis of the genetic structure underlying key traits in yam. Additionally, this study emphasizes the identification of SNP variants and genes that may be utilized for genomic-informed selection in order to enhance yield and disease resistance in yams. [ABSTRACT FROM AUTHOR]

Introduction: Yam is an important crop for food security in East and West Africa due to its high market value and customer demand. High tuber quality with yield and disease resistance are the main traits for acceptability of yam cultivars across the tropical zone. There has been limited progress in enhancing the production and quality traits of yams, despite the significant socio-economic significance of this crop. Method: To expedite the development of high-quality yam cultivars in Uganda, traits association study was conducted to identify genomic regions associated with key traits such as disease resistance, high yields, and dry matter content. The association mapping was conducted with multi-random mixed linear model (mrMLM) to compute the associations using five genetic models. Results: A total of 16 significant single nucleotide polymorphisms (SNPs) markers were identified to be associated with the traits studied. Gene identification analysis revealed the presence of key putative genes such as Vicilin-like seed storage protein At2g28490 (ARATH)and Growth-regulating factor 1 involved in a variety of functions ranging from storage and gene regulation for disease resistance. Discussion: The results obtained from this work have significant implications for the in-depth analysis of the genetic structure underlying key traits in yam. Additionally, this study emphasizes the identification of SNP variants and genes that may be utilized for genomic-informed selection in order to enhance yield and disease resistance in yams. [ABSTRACT FROM AUTHOR]

Background: The shea tree is a well-known carbon sink in Africa that requires a sustainable conservation of its gene pool. However, the genetic structure of its population is not well studied, especially in Côte d’Ivoire. In this study, 333 superior shea tree genotypes conserved in situ in Côte d’Ivoire were collected and genotyped with the aim of investigating its genetic diversity and population structure to facilitate suitable conservation and support future breeding efforts to adapt to climate change effects. Results: A total of 7,559 filtered high-quality single nucleotide polymorphisms (SNPs) were identified using the genotyping by sequencing technology. The gene diversity (HE) ranged between 0.1 to 0.5 with an average of 0.26, while the polymorphism information content (PIC) value ranged between 0.1 to 0.5 with an average of 0.24, indicating a moderate genetic diversity among the studied genotypes. The population structure model classified the 333 genotypes into three genetic groups (GP1, GP2, and GP3). GP1 contained shea trees that mainly originated from the Poro, Tchologo, and Hambol districts, while GP2 and GP3 contained shea trees collected from the Bagoué district. Analysis of molecular variance (AMOVA) identified 55% variance within populations and 45% variance within individuals, indicating a very low genetic differentiation (or very high gene exchange) between these three groups (FST = 0.004, gene flow Nm = 59.02). Morphologically, GP1 displayed spreading tree growth habit, oval nut shape, higher mean nut weight (10.62 g), wide leaf (limb width = 4.63 cm), and small trunk size (trunk circumference = 133.4 cm). Meanwhile, GP2 and GP3 showed similar morphological characteristics: erect and spreading tree growth habit, ovoid nut shape, lower mean nut weight (GP2: 8.89 g; GP3: 8.36 g), thin leaf (limb width = 4.45 cm), and large trunk size (GP2: 160.5 cm, GP3: 149.1 cm). A core set of 100 superior shea trees, representing 30% of the original population size and including individuals from all four study districts, was proposed using the “maximum length sub-tree function” in DARwin v. 6.0.21. Conclusion: These findings provide new knowledge of the genetic diversity and population structure of Ivorian shea tree genetic resources for the design of effective collection and conservation strategies for the efficient use of inbreeding. [ABSTRACT FROM AUTHOR]

Selection is a fundamental part of the plant breeding process, enabling the identification and development of varieties with desirable traits. Thanks to advances in genetics and biotechnology, the selection process has become more precise and efficient, resulting in faster breeding progress and better adaptation of crops to environmental challenges. Genetic parameters related to gene additivity and epistasis play a key role and can influence decisions on the suitability of breeding material. In this study, 188 rapeseed doubled haploid lines were assessed in field conditions for resistance to Leptosphaeria spp. Through next-generation sequencing, a total of 133,764 molecular markers (96,121 SilicoDArT and 37,643 SNP) were obtained. The similarity of the DH lines at the phenotypic and genetic levels was calculated. The results indicate that the similarity at the phenotypic level was markedly different from the similarity at the genetic level. Genetic parameters related to additive gene action effects and epistasis (double and triple) were calculated using two methods: based on phenotypic observations only and using molecular marker observations. All evaluated genetic parameters (additive, additive-additive and additive-additive-additive) were statistically significant for both estimation methods. The parameters associated with the interaction (double and triple) had opposite signs depending on the estimation method. [ABSTRACT FROM AUTHOR]

This study aimed to determine whether using DNA-based markers assigned to individual chromosomes would detect the genetic structures of 446 winter triticale forms originating from two breeding companies more effectively than using the entire pool of markers. After filtering for quality control parameters, 6380 codominant single nucleotide polymorphisms (SNPs) markers and 17,490 dominant diversity array technology (silicoDArT) markers were considered for analysis. The mean polymorphic information content (PIC) values varied depending on the chromosomes and ranged from 0.30 (2R) to 0.43 (7A) for the SNPs and from 0.28 (2A) to 0.35 (6R) for the silicoDArTs. The highest correlation of genetic distance (GD) matrices based on SNP markers was observed among the 5B–5R (0.642), 5B–7B (0.626), and 5A–5R (0.605) chromosomes. When silicoDArTs were used for the analysis, the strongest correlations were found between 5B–5R (0.732) and 2B–5B (0.718). A Bayesian analysis showed that SNPs (total marker pool) allowed for the identification of a more complex structure (K = 4, ΔK = 2460.2) than the analysis based on silicoDArTs (K = 2, ΔK = 128). Triticale lines formed into groups, ranging from two (most of the chromosomes) to four (7A) groups depending on the analyzed chromosome when SNP markers were used for analysis. Linkage disequilibrium (LD) varied among individual chromosomes, ranging from 0.031 for 1A to 0.228 for 7R. [ABSTRACT FROM AUTHOR]

Abstract Background The shea tree is a well-known carbon sink in Africa that requires a sustainable conservation of its gene pool. However, the genetic structure of its population is not well studied, especially in Côte d’Ivoire. In this study, 333 superior shea tree genotypes conserved in situ in Côte d’Ivoire were collected and genotyped with the aim of investigating its genetic diversity and population structure to facilitate suitable conservation and support future breeding efforts to adapt to climate change effects. Results A total of 7,559 filtered high-quality single nucleotide polymorphisms (SNPs) were identified using the genotyping by sequencing technology. The gene diversity (HE) ranged between 0.1 to 0.5 with an average of 0.26, while the polymorphism information content (PIC) value ranged between 0.1 to 0.5 with an average of 0.24, indicating a moderate genetic diversity among the studied genotypes. The population structure model classified the 333 genotypes into three genetic groups (GP1, GP2, and GP3). GP1 contained shea trees that mainly originated from the Poro, Tchologo, and Hambol districts, while GP2 and GP3 contained shea trees collected from the Bagoué district. Analysis of molecular variance (AMOVA) identified 55% variance within populations and 45% variance within individuals, indicating a very low genetic differentiation (or very high gene exchange) between these three groups (F ST = 0.004, gene flow Nm = 59.02). Morphologically, GP1 displayed spreading tree growth habit, oval nut shape, higher mean nut weight (10.62 g), wide leaf (limb width = 4.63 cm), and small trunk size (trunk circumference = 133.4 cm). Meanwhile, GP2 and GP3 showed similar morphological characteristics: erect and spreading tree growth habit, ovoid nut shape, lower mean nut weight (GP2: 8.89 g; GP3: 8.36 g), thin leaf (limb width = 4.45 cm), and large trunk size ( GP2: 160.5 cm, GP3: 149.1 cm). A core set of 100 superior shea trees, representing 30% of the original population size and including individuals from all four study districts, was proposed using the “maximum length sub-tree function” in DARwin v. 6.0.21. Conclusion These findings provide new knowledge of the genetic diversity and population structure of Ivorian shea tree genetic resources for the design of effective collection and conservation strategies for the efficient use of inbreeding.

A validated marker system is crucial to running an effective genomics-assisted breeding program. We used 36 Kompetitive Allele-Specific PCR (KASP) markers to genotype 376 clones from the biofortified cassava pipeline, and fingerprinted 93 of these clones with DArTseq markers to characterize breeding materials and evaluate their relationships. The discriminating ability of the 36-quality control (QC) KASP and 6602 DArTseq markers was assessed using 92 clones genotyped in both assays. In addition, trait-specific markers were used to determine the presence or absence of target genomic regions. Hierarchical clustering identified two major groups, and the clusters were consistent with the breeding program origins. There was moderate genetic differentiation and a low degree of variation between the identified groups. The general structure of the population was similar using both assays. Nevertheless, KASP markers had poor resolution when it came to differentiating the genotypes by seed sources and overestimated the prevalence of duplicates. The trait-linked markers did not achieve optimal performance as all markers displayed variable levels of false positive and/or false negative. These findings represent the initial step in the application of genomics-assisted breeding for the biofortified cassava pipeline, and will guide the use of genomic selection in the future. [ABSTRACT FROM AUTHOR]

Genomic selection (GS) has become an indispensable tool in modern plant breeding, particularly for complex traits. This study aimed to assess the efficacy of GS in predicting rust (Uromyces pisi) resistance in pea (Pisum sativum), using a panel of 320 pea accessions and a set of 26,045 Silico-Diversity Arrays Technology (Silico-DArT)markers. We compared the prediction abilities of different GS models and explored the impact of incorporatingmarker × environment (M×E) interaction as a covariate in the GBLUP (genomic best linear unbiased prediction) model. The analysis included phenotyping data from both field and controlled conditions. We assessed the predictive accuracies of different cross-validation strategies and compared the efficiency of using single traits versus a multi-trait index, based on factor analysis and ideotype-design (FAI-BLUP), which combines traits from controlled conditions. The GBLUP model, particularly when modified to include M×E interactions, consistently outperformed other models, demonstrating its suitability for traits affected by complex genotype-environment interactions (GEI). The best predictive ability (0.635) was achieved using the FAI-BLUP approach within the Bayesian Lasso (BL) model. The inclusion of M×E interactions significantly enhanced prediction accuracy across diverse environments in GBLUP models, although it did not markedly improve predictions for non-phenotyped lines. These findings underscore the variability of predictive abilities due to GEI and the effectiveness of multi-trait approaches in addressing complex traits. Overall, our study illustrates the potential of GS, especially when employing a multi-trait index like FAI-BLUP and accounting for M×E interactions, in pea breeding programs focused on rust resistance. [ABSTRACT FROM AUTHOR]

Blackleg disease, caused by Leptosphaeria spp. fungi, is one of the most important diseases of Brassica napus, responsible for severe yield losses worldwide. Blackleg resistance is controlled by major R genes and minor quantitative trait loci (QTL). Due to the high adaptation ability of the pathogen, R-mediated resistance can be easily broken, while the resistance mediated via QTL is believed to be more durable. Thus, the identification of novel molecular markers linked to blackleg resistance for B. napus breeding programs is essential. In this study, 183 doubled haploid (DH) rapeseed lines were assessed in field conditions for resistance to Leptosphaeria spp. Subsequently, DArTseq-based Genome-Wide Association Study (GWAS) was performed to identify molecular markers linked to blackleg resistance. A total of 133,764 markers (96,121 SilicoDArT and 37,643 SNP) were obtained. Finally, nine SilicoDArT and six SNP molecular markers were associated with plant resistance to Leptosphaeria spp. at the highest significance level, p < 0.001. Importantly, eleven of these fifteen markers were found within ten genes located on chromosomes A06, A07, A08, C02, C03, C06 and C08. Given the immune-related functions of the orthologues of these genes in Arabidopsis thaliana, the identified markers hold great promise for application in rapeseed breeding programs. [ABSTRACT FROM AUTHOR]

Although cowpea mild mottle virus (CPMMV) has been reported in Brazil since 1983, it has only become a significant concern for researchers and farmers in recent years. The objective of this work was to investigate the genetic basis of CPMMV tolerance, mapping and reporting the first loci associated with this trait in common bean (cv. BRS Sublime). Phenotypic assays were carried out on 180 individual plants (F2 generation) and 180 F2:3 progenies comprising 12 plants per family and their parents (BRS Sublime, tolerant parent × CNFCT 16207, susceptible parent). CPMMV was mechanically inoculated and symptoms were evaluated at 35 days after inoculation, using a 1–5 scoring scale. A linkage map was constructed using 1695 single‐nucleotide polymorphism (SNP) and SilicoDArT markers that segregated in the F2 and F2:3 generations as expected. Markers were distributed across 11 common bean chromosomes, resulting in a total length of 2864 cM, with an average distance between markers of 1.8 cM. Phenotypic observations revealed that tolerance in cv. BRS Sublime is controlled by a single dominant gene. The main effect quantitative trait locus (QTL; CPMMV.Pv08) associated with CPMMV tolerance was identified in the terminal region on chromosome 8 (Pv08). This QTL explained approximately 77% of phenotypic variation, indicating that the inheritance of tolerance to CPMMV is monogenic, controlled by a major locus. As far as we know, this study represents the first investigation into the inheritance and genetic mapping of CPMMV tolerance in common bean, with potential for the development of elite lines with multiple virus resistance/tolerance. [ABSTRACT FROM AUTHOR]

Introduction: Genotyping large-scale gene bank collections requires an appropriate sampling strategy to represent the diversity within and between accessions. Methods: A panel of 44 common bean (Phaseolus vulgaris L.) landraces from the Alliance Bioversity and The Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT) gene bank was genotyped with DArTseq using three sampling strategies: a single plant per accession, 25 individual plants per accession jointly analyzed after genotyping (in silico-pool), and by pooling tissue from 25 individual plants per accession (seq-pool). Sampling strategies were compared to assess the technical aspects of the samples, the marker information content, and the genetic composition of the panel. Results: The seq-pool strategy resulted inmore consistent DNA libraries for quality and call rate, although with fewer polymorphic markers (6,142 single-nucleotide polymorphisms) than the in silico-pool (14,074) or the single plant sets (6,555). Estimates of allele frequencies by seq-pool and in silico-pool genotyping were consistent, but the results suggest that the difference between pools depends on population heterogeneity. Principal coordinate analysis, hierarchical clustering, and the estimation of admixture coefficients derived froma single plant, in silico-pool, and seq-pool successfully identified the well-known structure of Andean and Mesoamerican gene pools of P. vulgaris across all datasets. Conclusion: In conclusion, seq-pool proved to be a viable approach for characterizing common bean germplasm compared to genotyping individual plants separately by balancing genotyping effort and costs. This study provides insights and serves as a valuable guide for gene bank researchers embarking on genotyping initiatives to characterize their collections. It aids curators in effectively managing the collections and facilitates marker-trait association studies, enabling the identification of candidate markers for key traits. [ABSTRACT FROM AUTHOR]

Leafless Bossiaea species are a unique group of plants endemic to Australia that present intriguing challenges in taxonomy and conservation because of their morphological simplicity and often small, disjunct populations. We employed whole genome reduced representation sequencing (DArTseq) to enhance our understanding of the population dynamics, diversity and taxonomy of leafless Bossiaea species. Our dataset comprised 52,539 single-nucleotide polymorphisms across 283 samples from 7 leafless Bossiaea species, including 6 listed threatened species. We examined population structure, phylogenetic relationships, kinship and gene flow within and among populations. On the basis of our population-genomic analyses, we propose recognition of the novel taxon Bossiaea vombata subsp. orientalis and a change in status from species (B. milesiae) to subspecies for B. fragrans subsp. milesiae. Additionally, we show extensive clonal reproduction across species and limited gene flow at distances of >1 km, shedding light on the challenges faced by these species. We advocate a coordinated approach to conservation, focusing on restoring self-sustaining populations and leveraging genetic rescue strategies. By addressing the population dynamics of multiple species simultaneously in taxonomically challenging lineages, we can make informed choices to safeguard biodiversity and evolutionary potential. This study investigates the population dynamics, diversity and taxonomy of leafless Bossiaea species, a distinctive group of Australian plants, by using whole-genome single-nucleotide polymorphism data. The findings suggest recognition of a new subspecies, Bossiaea vombata subsp. orientalis , and a change in status for B. milesiae to B. fragrans subsp. milesiae. We also highlight challenges in reproduction and gene flow among Bossiaea populations, emphasising the need for coordinated conservation efforts. (Image credit: Keith McDougall.) [ABSTRACT FROM AUTHOR]

IntroductionYam is an important crop for food security in East and West Africa due to its high market value and customer demand. High tuber quality with yield and disease resistance are the main traits for acceptability of yam cultivars across the tropical zone. There has been limited progress in enhancing the production and quality traits of yams, despite the significant socio-economic significance of this crop.MethodTo expedite the development of high-quality yam cultivars in Uganda, traits association study was conducted to identify genomic regions associated with key traits such as disease resistance, high yields, and dry matter content. The association mapping was conducted with multi-random mixed linear model (mrMLM) to compute the associations using five genetic models.ResultsA total of 16 significant single nucleotide polymorphisms (SNPs) markers were identified to be associated with the traits studied. Gene identification analysis revealed the presence of key putative genes such as Vicilin-like seed storage protein At2g28490 (ARATH)and Growth-regulating factor 1 involved in a variety of functions ranging from storage and gene regulation for disease resistance.DiscussionThe results obtained from this work have significant implications for the in-depth analysis of the genetic structure underlying key traits in yam. Additionally, this study emphasizes the identification of SNP variants and genes that may be utilized for genomic-informed selection in order to enhance yield and disease resistance in yams.

Crater lake fishes are common evolutionary model systems, with recent studies suggesting a key role for gene flow in promoting rapid adaptation and speciation. However, the study of these young lakes can be complicated by human-mediated extinctions. Museum genomics approaches integrating genetic data from recently extinct species are, therefore, critical to understanding the complex evolutionary histories of these fragile systems. Here, we examine the evolutionary history of an extinct Southern Hemisphere crater lake endemic, the rainbowfish Melanotaenia eachamensis. We undertook a comprehensive sampling of extant rainbowfish populations of the Atherton Tablelands of Australia alongside historical museum material to understand the evolutionary origins of the extinct crater lake population and the dynamics of gene flow across the ecoregion. The extinct crater lake species is genetically distinct from all other nearby populations due to historic introgression between 2 proximate riverine lineages, similar to other prominent crater lake speciation systems, but this historic gene flow has not been sufficient to induce a species flock. Our results suggest that museum genomics approaches can be successfully combined with extant sampling to unravel complex speciation dynamics involving recently extinct species. [ABSTRACT FROM AUTHOR]

Morphological variation is common within widely distributed plant species and often raises interesting taxonomic and evolutionary questions. We sampled eight typical inland populations and two coastal dwarf populations of Banksia occidentalis to assess whether the coastal variant warrants taxonomic recognition. Genomic (single nucleotide polymorphisms) and morphometric analyses were undertaken to assess the variation within and between variants. Genetically, the coastal populations were more closely related to geographically adjacent populations of the typical variant than they were to each other, indicating that each coastal population has originated independently. Morphologically, the coastal populations also did not represent a cohesive phenotypic group, with both falling outside the range of variation for the typical variant, but also not overlapping each other. Wide morphological, but not genomic, variation was identified along a coastal–inland transect. Combined, these data indicate that the morphological variation in these coastal populations is the result of parallel ecotype evolution from experiencing similar environmental conditions and does not represent the diversification of a distinct evolutionary lineage that would have warranted taxonomic recognition. Our study highlights the consequences of strong selection pressures in marginal environments and provides fascinating insight to the long evolutionary history of the flora in this ancient Australian landscape. [ABSTRACT FROM AUTHOR]

Faba bean (Vicia faba L.) is a legume crop grown in diverse climates worldwide. It has a high potential for increased cultivation to meet the need for more plantbased proteins in human diets, a prerequisite for a more sustainable food production system. Characterization of diversity panels of crops can identify variation in and genetic markers for target traits of interest for plant breeding. In this work, we collected a diversity panel of 220 accessions of faba bean from around the world consisting of gene bank material and commercially available cultivars. The aims of this study were to quantify the phenotypic diversity in target traits to analyze the impact of breeding on these traits, and to identify genetic markers associated with traits through a genome-wide association study (GWAS). Characterization under field conditions at Nordic latitude across two years revealed a large genotypic variation and high broad-sense heritability for eleven agronomic and seed quality traits. Pairwise correlations showed that seed yield was positively correlated to plant height, number of seeds per plant, and days to maturity. Further, susceptibility to bean weevil damage was significantly higher for early flowering accessions and accessions with larger seeds. In this study, no yield penalty was found for higher seed protein content, but protein content was negatively correlated to starch content. Our results showed that while breeding advances in faba bean germplasm have resulted in increased yields and number of seeds per plant, they have also led to a selection pressure towards delayed onset of flowering and maturity. DArTseq genotyping identified 6,606 single nucleotide polymorphisms (SNPs) by alignment to the faba bean reference genome. These SNPs were used in a GWAS, revealing 51 novel SNP markers significantly associated with ten of the assessed traits. Three markers for days to flowering were found in predicted genes encoding proteins for which homologs in other plant species regulate flowering. Altogether, this work enriches the growing pool of phenotypic and genotypic data on faba bean as a valuable resource for developing efficient breeding strategies to expand crop cultivation. [ABSTRACT FROM AUTHOR]

Common wheat (Triticum aestivum L.) is one of the most important species of crops. It is the most common cereal grown on all continents. Every year the yield of wheat on plantations all over the world is hugely reduced by yellow rust caused by the Puccinia striformis f. sp. tritici fungus. Apart from the yield potential and grain quality, resistance to diseases has become an important breeding goal. The identification and use of new sources of resistance is essential to improve the resistance of wheat plants to yellow rust. In this study, we performed a genome wide association study (GWAS) for the derived mapping population. The aim of this study was to find the silicoDArT and SNP markers coupled with the genes determining resistance to Puccinia striformis f. sp. tritici, which could be used to select yellow rust-resistant cultivars. Long-term observations resulted in the identification of a cultivar (Tobak) with very high resistance to infestation with yellow rust. This cultivar was crossed with a yellow rust-susceptible cultivar and a mapping population was derived and subjected to next-generation sequencing (NGS). As a result of the DArTseq analysis, 10,586 silicoDArT markers and 8,423 SNP markers were obtained. The obtained genotyping data was used for association mapping, which was performed using the GWAS method. The largest number of sequences similar to the sequences of the silicoDArT and SNP markers determined in the GWAS analysis were located on chromosome 2B. Further analyses resulted in the identification of region 36838943-536815801 on chromosome 2B, which contained three sequences related with resistance to diseases. Disease resistance genes involved in the plant defense system, such as the disease resistance proteins RAG1, RAG2 and RPP8, have been identified. [ABSTRACT FROM AUTHOR]

The genus Salix, comprising some 400–500 species, is important in various alluvial or wet habitats of the northern hemisphere. It is a promising crop for applications such as biomass production, biofuels, or environmental projects. Clear species delimitation is crucial in ecology, biotechnology, and horticulture. DArTseq markers, a genome-wide technique, were tested for species and hybrid identification. A total of 179 willow samples were analysed, including six species of Salix subgen. Salix and four species of Salix subgen. Vetrix, including those used in biomass crop production, representing important European taxa. Identification of species-specific markers, clustering analyses (principal coordinate analysis, neighbor-joining) and Bayesian methods (Structure) unambiguously identified putative hybrids. In addition to demonstrating the high efficiency of DArT-seq markers in identifying willow hybrids, we also opened-up new questions about hybridisation processes and systematics. We detected unidirectional hybridisation between S. alba and S. fragilis, forming backcross hybrids, and we rejected the hypothesis that S. fragilis does not occur naturally in Europe. Further, the isolated position of Salix triandra within the genus was confirmed. [ABSTRACT FROM AUTHOR]

Identifying sex-linked markers from genomic data has both theoretical and applied importance, especially in conservation. Yet, few methods and tools exist to detect such markers from Restriction-site-Associated DNA sequencing reads and even fewer tools can identify sex-linked markers from existing genotyped data. Here, we describe a new R function that can identify sex-linked markers in species with partially non-recombining sex chromosomes. We test the accuracy and speed of our function with an example dataset from a species of conservation concern, the White Shark, Carcharodon carcharias. We further compare our method against other approaches and find that our method detects more sex-linked markers that can be reliably mapped to reference genomes. Overall, we provide a conservation and fisheries-relevant tool that can reliably and efficiently assign sex from genetic data in species with a heterogametic sex and we demonstrate its utility by developing a sex-identification PCR test for White Sharks. [ABSTRACT FROM AUTHOR]

Genomic selection (GS) has become an indispensable tool in modern plant breeding, particularly for complex traits. This study aimed to assess the efficacy of GS in predicting rust (Uromyces pisi) resistance in pea (Pisum sativum), using a panel of 320 pea accessions and a set of 26,045 Silico-Diversity Arrays Technology (Silico-DArT) markers. We compared the prediction abilities of different GS models and explored the impact of incorporating marker × environment (M×E) interaction as a covariate in the GBLUP (genomic best linear unbiased prediction) model. The analysis included phenotyping data from both field and controlled conditions. We assessed the predictive accuracies of different cross-validation strategies and compared the efficiency of using single traits versus a multi-trait index, based on factor analysis and ideotype-design (FAI-BLUP), which combines traits from controlled conditions. The GBLUP model, particularly when modified to include M×E interactions, consistently outperformed other models, demonstrating its suitability for traits affected by complex genotype-environment interactions (GEI). The best predictive ability (0.635) was achieved using the FAI-BLUP approach within the Bayesian Lasso (BL) model. The inclusion of M×E interactions significantly enhanced prediction accuracy across diverse environments in GBLUP models, although it did not markedly improve predictions for non-phenotyped lines. These findings underscore the variability of predictive abilities due to GEI and the effectiveness of multi-trait approaches in addressing complex traits. Overall, our study illustrates the potential of GS, especially when employing a multi-trait index like FAI-BLUP and accounting for M×E interactions, in pea breeding programs focused on rust resistance.

IntroductionGenotyping large-scale gene bank collections requires an appropriate sampling strategy to represent the diversity within and between accessions.MethodsA panel of 44 common bean (Phaseolus vulgaris L.) landraces from the Alliance Bioversity and The Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT) gene bank was genotyped with DArTseq using three sampling strategies: a single plant per accession, 25 individual plants per accession jointly analyzed after genotyping (in silico–pool), and by pooling tissue from 25 individual plants per accession (seq-pool). Sampling strategies were compared to assess the technical aspects of the samples, the marker information content, and the genetic composition of the panel.ResultsThe seq-pool strategy resulted in more consistent DNA libraries for quality and call rate, although with fewer polymorphic markers (6,142 single-nucleotide polymorphisms) than the in silico–pool (14,074) or the single plant sets (6,555). Estimates of allele frequencies by seq-pool and in silico–pool genotyping were consistent, but the results suggest that the difference between pools depends on population heterogeneity. Principal coordinate analysis, hierarchical clustering, and the estimation of admixture coefficients derived from a single plant, in silico–pool, and seq-pool successfully identified the well-known structure of Andean and Mesoamerican gene pools of P. vulgaris across all datasets.ConclusionIn conclusion, seq-pool proved to be a viable approach for characterizing common bean germplasm compared to genotyping individual plants separately by balancing genotyping effort and costs. This study provides insights and serves as a valuable guide for gene bank researchers embarking on genotyping initiatives to characterize their collections. It aids curators in effectively managing the collections and facilitates marker-trait association studies, enabling the identification of candidate markers for key traits.

This study aimed to determine whether using DNA-based markers assigned to individual chromosomes would detect the genetic structures of 446 winter triticale forms originating from two breeding companies more effectively than using the entire pool of markers. After filtering for quality control parameters, 6380 codominant single nucleotide polymorphisms (SNPs) markers and 17,490 dominant diversity array technology (silicoDArT) markers were considered for analysis. The mean polymorphic information content (PIC) values varied depending on the chromosomes and ranged from 0.30 (2R) to 0.43 (7A) for the SNPs and from 0.28 (2A) to 0.35 (6R) for the silicoDArTs. The highest correlation of genetic distance (GD) matrices based on SNP markers was observed among the 5B–5R (0.642), 5B–7B (0.626), and 5A–5R (0.605) chromosomes. When silicoDArTs were used for the analysis, the strongest correlations were found between 5B–5R (0.732) and 2B–5B (0.718). A Bayesian analysis showed that SNPs (total marker pool) allowed for the identification of a more complex structure (K = 4, ΔK = 2460.2) than the analysis based on silicoDArTs (K = 2, ΔK = 128). Triticale lines formed into groups, ranging from two (most of the chromosomes) to four (7A) groups depending on the analyzed chromosome when SNP markers were used for analysis. Linkage disequilibrium (LD) varied among individual chromosomes, ranging from 0.031 for 1A to 0.228 for 7R.

Habitat fragmentation can increase the chance of population bottlenecks and inbreeding, and may ultimately lead to reduced fitness and local extinction. Notelaea lloydii is a native olive species endemic to Australia and listed as vulnerable due to its restricted distribution. A recent molecular systematics study has revealed there might be some geographic structuring among N. lloydii populations. Therefore, we undertook a genome‐wide single nucleotide polymorphism (SNP) analysis to determine levels and patterns of genetic diversity, inbreeding and gene flow within and among N. lloydii populations in south‐eastern Queensland. Furthermore, as the reproductive phase of a plant's life history has a profound influence on genetic diversity, life history reproductive traits were also studied. Our SNP analysis revealed low genetic diversity, inbreeding and significant genetic structuring even among proximate populations. Results of a flower and fruit bagging experiment in two consecutive seasons revealed that N. lloydii produced many flowers but only a few fruits survived to maturity. There were no differences in bagged and un‐bagged flowering and fruiting rates, and therefore, we conclude that the high fruit abortion rate was probably due to inbreeding depression and/or suboptimal conditions, rather than pollinator availability and insect attack. Overall, results of this study indicate that the populations of N. lloydii are small, inbred and genetically isolated and represent unique management units that require local conservation management due to ongoing threats associated with urbanisation. [ABSTRACT FROM AUTHOR]

Genetic improvement of tea for both health and economic benefit requires proper genetic characterization of sequence variation present in tea accession especially those conserved in the ex-situ genebanks. Here, we studied the genetic variation and population structure of 376 tea germplasm at Rwebitaba Tea Research Centre (RTRC), a tea research station with the largest collections of tea germplasm in East Africa. The study was conducted using 8480 (22.7%) diversity array technology (DArT) SNP markers. These markers had a high call rate of 77% with mean polymorphic information content (P.I.C) of 0.12 and minor allelic frequency of 0.08. The expected heterozygosity (He) varied from 0.05 to 0.15 while the observed heterozygosity (Ho) varied from 0.01 to 0.26. The overall inbreeding coefficient (FIS) was 0.45, with some populations showing a high level of outcrossing (FIS = − 0.035). Analysis of molecular variance revealed a high within-population variance (88.9%) showing weak genetic differentiation between populations (PhiPT = 0.111). Structure analysis showed the presence of eight clusters, with all sub-populations highly admixed except for a few tea clones such as Ch-06 and Ch-07. Phylogenetic analysis confirmed the clustering, showing interrelatedness between different tea genotypes, which will facilitate the selection of parents for increased genetic gain and breeding efficiency in tea breeding. In general, the genetic diversity of tea genotypes is relatively low, with high variation within the existing tea populations. These results showed that the existing variation can be exploited for the development of unique tea genotypes in Uganda. [ABSTRACT FROM AUTHOR]

Faba bean is a major legume crop that contains a substantial amount of nutritious compounds that our bodies require for maintenance and is also a valuable crop in various other aspects. The present study aimed to investigate agronomic trait diversity in Turkish faba bean germplasm. A total of 372 faba bean genotypes and 3 commercial cultivars were used as plant material and field experiments were conducted in three Turkish provinces (Adana, Izmir, and Sivas) over the two growing seasons 2016–2017 and 2017–2018 according to the augmented block design. A total of 14 agronomic traits were observed and analysis of variance elucidated that the examined factors had a high and significant effect on the most morphological traits (p < 0.0001), Furthermore the results showed a high degree of variation in the first pod height (21.68–38.74 cm), plant height (57.18–71.41 cm), pod length (5.66–7.53 cm), days to flowering (51.00–61.33), pod weight (57.51–70.68 g), 100 seed weight (62.56–231.04 g), biological yield (31.13–44.56 g/plant), grain yield per plant (31.21–41.39 g) and grain yield (227.14–270.78 kg/Da) traits. Correlation analysis showed a positive and significant relationship between the yield per plant, the days to flowering, the number of seeds per pod and with 100 seed weight, the number of pods per plant, pod length and pod weight, and finally, pod length and pod weight. Genotyping by sequencing (GBS) analysis was performed and resulted in 23,661 DArTseq markers. Marker-trait association was performed using MLM (Kinship + PCA) approach that revealed a total of 34 markers for the evaluated traits. We think that resulted markers will be helpful for the future marker-assisted breeding of faba bean. [ABSTRACT FROM AUTHOR]

Context: Wild sorghum taxa (Sorghum Moench) cover much of the northern Australian landscape and harbour potentially useful traits for crop improvement. Specialised metabolites such as phenolics, silicon and cyanogenic glucosides (which are toxic to grazing animals) are present in Sorghum and have been associated with drought tolerance. However, these taxa remain poorly studied, especially regarding intraspecific variation. Aims: To investigate the intraspecific diversity of wild sorghums growing along aridity clines, including morphology, biochemistry and genotype. We hypothesised that genotypic and phenotypic diversity would co-vary with niche diversity. Methods: Multiple accessions of Sorghum plumosum , S. stipoideum and S. timorense were grown under common conditions for 10 weeks. Concentrations of cyanogenic glucosides, phenolics and silicon were measured alongside five morphological traits. Accessions were genotyped using single-nucleotide polymorphisms. Key results: Several traits varied significantly within species, but no trait consistently co-varied with aridity across species. In S. timorense , there appeared to be genotypic differentiation among accessions, but this was not translated into phenotypic differences, which was likely to be due to similarities in climate. Conclusions: Our results challenge assumptions that phenotypic and genotypic diversity correlate with niche diversity and support the hypothesis that mature Australian wild sorghums store most of their cyanogenic glucosides in their roots. Implications: Wild sorghums harbour advantageous traits for crop improvement, such as niche diversity and low toxicity. Future wild sorghum research must acknowledge intraspecific diversity, and as many populations as possible should be conserved, because genetic diversity is not necessarily discernible from phenotype or provenance alone. Accessions of three wild sorghum species collected in Australia. Wild Sorghum species dominate parts of northern Australia and contain potentially useful traits for crop improvement, but the diversity within these species has not been sufficiently examined. We assessed phenotypic and genotypic diversity of three Sorghum species and found unexpected complexity in the relationships among the environment, genotype and phenotype. Our results challenge assumptions that diversity levels can be assumed from phenotype or environment alone, with implications for conservation and crop improvement. Photograph by Jack McCausland. [ABSTRACT FROM AUTHOR]

Cowpea is a grain legume that is commonly grown in Sub-Saharan Africa (SSA) for a variety of uses including food, feed, and soil fertility enhancement through nitrogen fixation. Genetic improvement in cowpea can be accomplished by creating breeding populations from high-performing but genetically diverse parental lines. The goal of this study was to use single nucleotide polymorphic markers (SNPs) to estimate genetic diversity and population stratification among cowpea parental genotypes from five countries. A total of 2,746 SNP markers were used to analyze 62 cowpea genotypes that differed in key characteristics. Only 55% of the SNP markers were polymorphic across the 62 genotypes and met the selection requirement. The gene diversity varied from 0.52 to 0.57 with an average of 0.55, while the polymorphic information content ranged from 0.46 to 0.51 with an average of 0.49, showing that the cowpea parental lines are genetically diverse. The analysis of molecular variance (AMOVA) found high significant (p < 0.001) variation among genotypes and non-significant variation across genotypes depending on country of origin. The cluster analysis for the 62 genotypes using the unweighted pair group procedure with arithmetic mean approach divided the genotypes into two distinct groups. Genotypes from the same geographical regions tended to cluster together and there was a significant level of genetic variation among genotypes from Uganda and Nigeria. The SNP markers utilized in this study were effective at distinguishing genotypes and may be used to estimate the diversity in the cowpea core collection. The genetic diversity in this collection is important for future development of improved varieties of cowpea in Uganda. [ABSTRACT FROM AUTHOR]

A validated marker system is crucial to running an effective genomics-assisted breeding program. We used 36 Kompetitive Allele-Specific PCR (KASP) markers to genotype 376 clones from the biofortified cassava pipeline, and fingerprinted 93 of these clones with DArTseq markers to characterize breeding materials and evaluate their relationships. The discriminating ability of the 36-quality control (QC) KASP and 6602 DArTseq markers was assessed using 92 clones genotyped in both assays. In addition, trait-specific markers were used to determine the presence or absence of target genomic regions. Hierarchical clustering identified two major groups, and the clusters were consistent with the breeding program origins. There was moderate genetic differentiation and a low degree of variation between the identified groups. The general structure of the population was similar using both assays. Nevertheless, KASP markers had poor resolution when it came to differentiating the genotypes by seed sources and overestimated the prevalence of duplicates. The trait-linked markers did not achieve optimal performance as all markers displayed variable levels of false positive and/or false negative. These findings represent the initial step in the application of genomics-assisted breeding for the biofortified cassava pipeline, and will guide the use of genomic selection in the future.

Abstract Habitat fragmentation can increase the chance of population bottlenecks and inbreeding, and may ultimately lead to reduced fitness and local extinction. Notelaea lloydii is a native olive species endemic to Australia and listed as vulnerable due to its restricted distribution. A recent molecular systematics study has revealed there might be some geographic structuring among N. lloydii populations. Therefore, we undertook a genome‐wide single nucleotide polymorphism (SNP) analysis to determine levels and patterns of genetic diversity, inbreeding and gene flow within and among N. lloydii populations in south‐eastern Queensland. Furthermore, as the reproductive phase of a plant's life history has a profound influence on genetic diversity, life history reproductive traits were also studied. Our SNP analysis revealed low genetic diversity, inbreeding and significant genetic structuring even among proximate populations. Results of a flower and fruit bagging experiment in two consecutive seasons revealed that N. lloydii produced many flowers but only a few fruits survived to maturity. There were no differences in bagged and un‐bagged flowering and fruiting rates, and therefore, we conclude that the high fruit abortion rate was probably due to inbreeding depression and/or suboptimal conditions, rather than pollinator availability and insect attack. Overall, results of this study indicate that the populations of N. lloydii are small, inbred and genetically isolated and represent unique management units that require local conservation management due to ongoing threats associated with urbanisation.

In marginal, arid, and semi-arid areas of Morocco, crops are often exposed to multiple abiotic and biotic stresses that have a major impact on yield. Farmer-maintained Moroccan landraces have been shaped by the impact of very strong selection pressures, gradually adapting to the local ecosystem and obsolete low-input agricultural practices without improvement towards high yield and quality. Considering the increasing threat of drought in Poland, it is necessary to introduce germplasm with tolerance to water deficit into barley breeding programs. The aim of this research was a DArTseq-based genetic characterization of a collection of germplasm of Moroccan origin, conserved in the Polish genebank. The results showed that all conserved landraces have a high level of heterogeneity and their gene pool is different from the material developed by Polish breeders. Based on the analysis of eco-geographical data, locations with extremely different intensities of drought stress were selected. A total of 129 SNPs unique to accessions from these locations were identified. In the neighborhood of the clusters of unique SNPs on chromosomes 5H and 6H, genes that may be associated with plant response to drought stress were identified. The results obtained may provide a roadmap for further research to support Polish barley breeding for increased drought tolerance. [ABSTRACT FROM AUTHOR]

Barley is one of the economically important crop species and the net form of net blotch (NFNB) caused by Pyrenophora teres f. teres has a significant impact on the quantity and quality of grain yield. Selection and inbreeding have resulted in a lack of genetic diversity in elite barley accessions. Old varieties often possess unique genetic traits that may have been lost in modern crop breeding. Therefore, the aim of the current study was to identify sources of resistance to barley NFNB in the collection of European old varieties. In this study, 431 European barley accessions were evaluated phenotypically under field conditions scoring APR to NFNB and genotypically using DArTseq. The range of adult plant resistance (APR) variability at the HA growth stage was sufficient to determine marker–trait associations (MTAs). The net form of net blotch at the HA stage was scored with a range of 1.0–4.0 according to a scale of 1–9, and GWAS identified 10 marker–trait associations (MTAs) for NFNB resistance. In the HA stage, two MTAs were identified on each chromosome 1H, 3H, 5H and 6H. Moreover, one was identified on the chromosome 7H and un. One of these MTA is localized on chromosome 6H, corresponding with findings from other studies, and could contribute to the exploration of genetic resistance of barley to NFNB. Additionally, the results of this study will be utilized to establish a Polish Gene Bank platform for precise breeding programs. [ABSTRACT FROM AUTHOR]

Spectacular scientific advances in the area of molecular biology and the development of modern biotechnological tools have had a significant impact on the development of maize heterosis breeding. One technology based on next-generation sequencing is DArTseq. The plant material used for the research consisted of 13 hybrids resulting from the crossing of inbred maize lines. A two-year field experiment was established at two Polish breeding stations: Smolice and Łagiewniki. Nine quantitative traits were observed: cob length, cob diameter, core length, core diameter, number of rows of grain, number of grains in a row, mass of grain from the cob, weight of one thousand grains, and yield. The isolated DNA was subjected to DArTseq genotyping. Association mapping was performed using a method based on the mixed linear model. A total of 81602 molecular markers (28571 SNPs and 53031 SilicoDArTs) were obtained as a result of next-generation sequencing. Out of 81602, 15409 (13850 SNPs and 1559 SilicoDArTs) were selected for association analysis. The 105 molecular markers (8 SNPs and 97 SilicoDArTs) were associated with the heterosis effect of at least one trait in at least one environment. A total of 186 effects were observed. The number of statistically significant relationships between the molecular marker and heterosis effect varied from 8 (for cob length) and 9 (for yield) to 42 (for the number of rows of grain). Of particular note were three markers (2490222, 2548691 and 7058267), which were significant in 17, 8 and 6 cases, respectively. Two of them (2490222 and 7058267) were associated with the heterosis effects of yield in three of the four environments.

Ascochyta lentis, the causal organism of Ascochyta blight (AB) of lentil (Lens culinaris), has been shown to produce an avirulence effector protein that mediates AB resistance in certain lentil cultivars. The two known forms of the effector protein were identified from a biparental mapping population between isolates that have reciprocal virulence on 'PBA Hurricane XT' and 'Nipper'. The effector AlAvrl-1 was described for the PBA Hurricane XT-avirulentisolate P94-24 and Al Avrl-2 characterized in the PBA Hurricane XT-virulent isolate A/Kewell. Here, we performed a genome-wide association study to identify other loci associated with AB for a differential set of lentil cultivars from a diverse panel of isolates collected in the Australian lentil-growing regions from 2013 to 2020. The chromosome 3 AlAvrl locus was strongly associated with the PBA Hurricane XT, 'Indianhead', and Nipper disease responses, but one other genomic region on chromosome 11 was also associated with the Nipper disease trait. Our results corroborate earlier work that identified the AlAvrl locus for field-collected isolates that span the period before release and after widespread adoption of PBA Hurricane XT. A multiplex PCR assay was developed to differentiate the genes AlAvrl-1 and AlAvrl-2 to predict PBA Hurricane XT avirulence and pathotype designation in the diversity panel. Increasing numbers of the PBA Hurricane XT-virulent pathotype 2 isolates across that time indicate strong selection for isolates with the AlAvrl-2 allele. Furthermore, one other region of the A. lentis genome may contribute to the pathogen-host interaction for lentil AB. [ABSTRACT FROM AUTHOR]

Introduction: Common bean is one of the widely consumed food security crop in Africa, Asia, and South America. Understanding genetic diversity and population structure is crucial for designing breeding strategies. Materials: Two hundred and eighty-nine germplasm were recently collected from different regions of Ethiopia and introduced from CIAT to estimate genetic diversity and population structure using 11,480 DArTSeq SNP markers. Results: The overall mean genetic diversity and polymorphic information content (PIC) were 0.38 and 0.30, respectively, suggested the presence of adequate genetic diversity among the genotypes. Among the geographical regions, landraces collected from Oromia showed the highest diversity (0.39) and PIC (0.30). The highest genetic distance was observed between genotypes collected from SNNPR and CIAT (0.49). In addition, genotypes from CIAT were genetically more related to improved varieties than the landraces which could be due to sharing of parents in the improvement process. The analysis of molecular variance revealed that the largest proportion of variation was due to within the population both in geographical region (63.67%) and breeding status (61.3%) based classification. Model-based structure analysis delineated the 289 common bean genotypes into six hypothetical ancestoral populations. Conclusions: The genotypes were not clustered based on geographical regions and they were not the main drivers for the differentiation. This indicated that selection of the parental lines should be based on systematic assessment of the diversity rather than geographical distance. This article provides new insights into the genetic diversity and population structure of common bean for association studies, designing effective collection and conservation for efficient utilization for the improvement of the crop. [ABSTRACT FROM AUTHOR]

Understanding the genetic diversity and population structure of rice is crucial for breeding programs, conservation efforts, and the development of sustainable agricultural practices. This study aimed to assess the genetic diversity and population structure of 94 rice (Oryza sativa L.) genotypes from the Democratic Republic of Congo using a set of 8389 high-quality DArTseq-based single nucleotide polymorphism (SNP) markers. The average polymorphic information content (PIC) of the markers was 0.25. About 42.4% of the SNPs had a PIC value between 0.25 and 0.5, which were moderately informative. The ADMIXTURE program was used for structure analysis, which revealed five sub-populations (K = 5), with admixtures. In principal component analysis (PCA), the first three principal components accounted for 36.3% of the total variation. Analysis of molecular variance revealed significant variation between sub-populations (36.09%) and within genotypes (34.04%). The low overall number of migrants (Nm = 0.23) and high fixation index (Fst = 0.52) indicated limited gene flow and significant differentiation between the sub-populations. Observed heterozygosity (Ho = 0.08) was lower than expected heterozygosity (He = 0.14) because of the high inbreeding (Fis = 0.52) nature of rice. A high average Euclidean genetic distance (0.87) revealed the existence of genetic diversity among the 94 genotypes. The significant genetic diversity among the evaluated rice genotypes can be further explored to obtain potentially desirable genes for rice improvement. [ABSTRACT FROM AUTHOR]

Conservation decision‐making and prioritization of management actions for taxa at high risk of extinction require a clear understanding of systematic relationships and species boundaries. Taxonomic uncertainty surrounds two threatened species of native olive (genus Notelaea) endemic to Australia. Notelaea ipsviciensis is known from only one small population and is listed as critically endangered under Australian and Queensland legislation, while Notelaea lloydii is listed as vulnerable due to its restricted distribution in south‐east Queensland, Australia. Notelaea ipsviciensis occurs in sympatry with N. lloydii, at the only site where it is found, and exhibits intermediate morphology between N. lloydii and Notelaea ovata raising speculation that it is a natural hybrid of the two. To address this uncertainty, we have reconstructed the molecular phylogeny of the genus Notelaea using both single‐gene sequencing and single nucleotide polymorphism (SNP) data. While the chloroplast DNA markers were not found to be informative, the genome‐wide SNPs used in this study have unequivocally resolved the long‐standing question of the hybrid origin of N. ipsviciensis. Results of the phylogenetics and hybrid analyses of SNP data show that N. ipsviciensis is a natural hybrid of N. lloydii and N. ovata, and the taxon's circumscription needs to be re‐evaluated. Our results also revealed unclear species boundaries among numerous other Notelaea species, including the threatened N. lloydii, indicating that further investigation and taxonomic revision may be necessary. [ABSTRACT FROM AUTHOR]

Common bean is one of the widely consumed food security crop in Africa, Asia and South America. It is a rich source of protein, minerals and micronutrients. High genotype by environment interaction is one of the main challenge in breeding for high grain micronutrient concentration. The objective of this study was to estimate SNP markers associated with grain Fe and Zn concentration using 289 common bean genotypes and 11,480 SNP markers. The study revealed that 43 quantitative trait loci (QTLs) were associated with grain Fe and Zn concentration. Five quantitative trait nucleotides (QTNs), that is, QTN Fe_1.1, QTN Fe_6.3, QTN Fe_6.5, QTN Fe_10.3 and QTN Fe_11.6 were detected both at Haramaya and Melkassa locations. Two of the markers, that is, QTN Fe_6.3 and QTN Fe_6.5, were located on chromosome 06 while QTN Fe_1.1, QTN Fe_10.3 and QTN Fe_ 11.6 were residing on chromosomes 01, 10 and 11, respectively. Among these, QTN Fe_11.6 had a large and positive consistent effect across locations. The five stable QTNs along with the potential candidate genes could be used for Fe biofortification through marker assisted selection. [ABSTRACT FROM AUTHOR]

Festuca is one of the largest genera within the Poaceae family. Molecular phylogenies demonstrate that Festuca s.l. comprises two groups: broad‐ and fine‐leaved species. The latter is the species‐richest and taxonomically complicated group due to being paraphyletic. Here, we provide the first insight into the phylogeny of 17 fine‐leaved species of Altai fescues. Based on genome‐wide genotyping, the examined taxa were divided into three markedly differentiated clusters. The first cluster comprises species from the F. rubra complex, the second cluster includes the F. brachyphylla complex, and the third cluster contains taxa from the groups F. ovina, F. valesiaca, and F. kryloviana. Importantly, we detected a complex genetic pattern within the groups of F. valesiaca and F. kryloviana. Moreover, our findings underline a discrepancy between morphological and molecular data for some species distributed within the Altai Mountain Country. We suggest that in order to validate the current findings on the fine‐leaved fescues, additional comprehensive research including morphological, karyological, and molecular methods is required. Nonetheless, our work provides a baseline for further investigations on the genus and studies on the floral diversity of Asia. [ABSTRACT FROM AUTHOR]

This study was undertaken to investigate the diversity and population structure of 487 oat accessions, including breeding lines from the ongoing programs of the three largest Polish breeding companies, along with modern and historical Polish and foreign cultivars. The analysis was based on 7411 DArTseq-derived SNPs distributed among three sub-genomes (A, C, and D). The heterogeneity of the studied material was very low, as only cultivars and advanced breeding lines were examined. Principal component analysis (PCA), principal coordinate analysis (PCoA), and cluster and STRUCTURE analyses found congruent results, which show that most of the examined cultivars and materials from Polish breeding programs formed major gene pools, that only some accessions derived from Strzelce Plant Breeding, and that foreign cultivars were outside of the main group. During the 120 year oat breeding process, only 67 alleles from the old gene pool were lost and replaced by 67 new alleles. The obtained results indicate that no erosion of genetic diversity was observed within the Polish native oat gene pool. Moreover, current oat breeding programs have introduced 673 new alleles into the gene pool relative to historical cultivars. The analysis also showed that most of the changes in relation to historical cultivars occurred within the A sub-genome with emphasis on chromosome 6A. The targeted changes were the rarest in the C sub-genome. This study showed that Polish oat breeding based mainly on traditional breeding methods—although focused on improving traits typical to this crop, i.e., enhancing the grain yield and quality and improving adaptability—did not significantly narrow the oat gene pool and in fact produced cultivars that are not only competitive in the European market but are also reservoirs of new alleles that were not found in the analyzed foreign materials. [ABSTRACT FROM AUTHOR]

The Coffea canephora germplasm, found in old seed crops in southern Espírito Santo, Brazil, represents a valuable genetic resource for coffee breeding programs. However, the renewal of these crops by clonal cultivars can narrow down the genetic base. Thus, this study aims to characterize the genetic diversity and population structure of 280 C. canephora genotypes from selected matrices in old (15–46-year-old) seed crops from southern Espírito Santo using Single Nucleotide Polymorphism (SNP) markers. Out of the 9491 SNPs retrieved from the Diversity Array Technology™ sequencing, 2542 high-quality SNPs were used for diversity and population STRUCTURE analyses, which detected two genetic pools. Cluster analysis revealed six clusters, some of which showed a high frequency of expected heterozygotes (HE), an indicative of the genetic diversity (GD) within this population. Clusters 4, 5, and 6, especially, harbor an abundance of heterozygous loci. High FST values were detected between clusters 4 and 2 (0.60), 2 and 5 (0.60), and 4 and 3 (0.50) and between the two genetic pools (0.59). This population's higher GD indices demonstrate that the old seed crops from southern Espírito Santo constitute a noticeably rich germplasm bank. This valuable source must be maintained and conserved to ensure coffee crop sustainability since it can broaden the genetic base once reduced by the replacement of crops with clonal cultivars. [ABSTRACT FROM AUTHOR]

The genus Salix, comprising some 400–500 species, is important in various alluvial or wet habitats of the northern hemisphere. It is a promising crop for applications such as biomass production, biofuels, or environmental projects. Clear species delimitation is crucial in ecology, biotechnology, and horticulture. DArTseq markers, a genome-wide technique, were tested for species and hybrid identification. A total of 179 willow samples were analysed, including six species of Salix subgen. Salix and four species of Salix subgen. Vetrix, including those used in biomass crop production, representing important European taxa. Identification of species-specific markers, clustering analyses (principal coordinate analysis, neighbor-joining) and Bayesian methods (Structure) unambiguously identified putative hybrids. In addition to demonstrating the high efficiency of DArT-seq markers in identifying willow hybrids, we also opened-up new questions about hybridisation processes and systematics. We detected unidirectional hybridisation between S. alba and S. fragilis, forming backcross hybrids, and we rejected the hypothesis that S. fragilis does not occur naturally in Europe. Further, the isolated position of Salix triandra within the genus was confirmed.

The genus Stipa is one of the largest genera of Poaceae. The phylogeny of the genus is still poorly resolved, and one of the main problems is linked to the extensive inter and intrasectional hybridization. Disclosure of hybridization processes is a key to understanding relationships between species within the genus. During a floristic study in feathergrass steppe ecosystems of central Asia, we found challenging specimens of Stipa with an interesting combination of morphological characters suggesting their origination through hybridization between morphologically and phylogenetically distant species. To confirm our hypothesis, we applied a combination of classical morphological and genome-wide SNP genotyping methods. Using such an approach, we determined that the new taxon named Stipa × smelanskyi arose from crossing S. richteriana and S. drobovii and confirmed that it is an F1 hybrid. Moreover, we found a S. drobovii specimen with a minor admixture of S. richteriana loci that may indicate putative introgression events among these taxa.

Introduction: Bambara groundnut (BG) (Vigna subterranea [L.] Verdc) is an indigenous, resilient, but underutilized leguminous crop that occurs mostly as genetically heterogeneous landraces with limited information on the drought tolerant attributes. This study elucidates the associations between sequencing-based diversity array technology (DArTseq) and phenotypic character as well as differing indices related to drought tolerance in one hundred accessions of Bambara groundnut. Methods: The field experiments were conducted at IITA research stations in Kano and Ibadan between 2016 and 2018 planting seasons. The experiments were arranged in randomised complete block design with three replications, under the different water regimes. The phenotypic traits evaluated was further to construct the dendrogram. Genome-wide association mapping was conducted based on 5927 DArTs loci with < 20% missing data. Results and Discussions: The genome wide association study predicted drought tolerance in Bambara accessions for geometric mean productivity (GMP) and stress tolerance index (STI). TVSu-423 had the highest GMP and STI values (28.50, 2.40), while TVSu-2017 had the lowest at GMP (1.74) and STI (0.01) respectively. The relative water content (%) was significantly higher for accessions; TVSu-266 (60.35, 61.49), TVSu-2 (58.29, 53.94), and TVSu-411 (55.17, 58.92) in 2016/2017 and 2017/2018, respectively. The phenotypic characters studied delineated the accessions into two major clusters and five distinct sub-clusters, indicating variations across all the geographical locations. The 5,927 DArTseq genomic markers in association with STI further grouped the 100 accessions into two main clusters. TVSu-1897 from Botswana (Southern Africa) was in the first cluster, while the remaining 99 accessions from Western, Central, and Eastern Africa made up the second cluster. The eight significant Quantitative Trait Loci (QTLs) (24346377|F|0-22:A>G-22:A>G, 24384105| F|0-56:A>G33 :A> G, 24385643|F|0-53:G>C-53:G>C, 24385696|F|0-43:A>G-43: A>G, 4177257|F|0-44:A>T-44:A>T, 4182070|F|0-66:G>A-66:G>A, 4183483|F|0-24: G>A-24:G>A, 4183904|F|0-11:C>T-11:C>T) identified with Bonferroni threshold was in association with STI, indicative of variations under the drought-stressed condition. The observation of consistent SNPs in the 2016 and 2017 planting seasons, as well as in combination with the 2016 and 2017 planting seasons, led to the designation of these QTLs as significant. The drought selected accessions could form basis for hybridization breeding. The identified quantitative trait loci could be useful in marker-assisted selection in drought molecular breeding programs. [ABSTRACT FROM AUTHOR]

The Bull Shark (Carcharhinus leucas) faces varying levels of exploitation around the world due to its coastal distribution. Information regarding population connectivity is crucial to evaluate its conservation status and local fishing impacts. In this study, we sampled 922 putative Bull Sharks from 19 locations in the first global assessment of population structure of this cosmopolitan species. Using a recently developed DNA‐capture approach (DArTcap), samples were genotyped for 3400 nuclear markers. Additionally, full mitochondrial genomes of 384 Indo‐Pacific samples were sequenced. Reproductive isolation was found between and across ocean basins (eastern Pacific, western Atlantic, eastern Atlantic, Indo‐West Pacific) with distinct island populations in Japan and Fiji. Bull Sharks appear to maintain gene flow using shallow coastal waters as dispersal corridors, whereas large oceanic distances and historical land‐bridges act as barriers. Females tend to return to the same area for reproduction, making them more susceptible to local threats and an important focus for management actions. Given these behaviors, the exploitation of Bull Sharks from insular populations, such as Japan and Fiji, may instigate local decline that cannot readily be replenished by immigration, which can in turn affect ecosystem dynamics and functions. These data also supported the development of a genetic panel to ascertain the population of origin, which will be useful in monitoring the trade of fisheries products and assessing population‐level impacts of this harvest. [ABSTRACT FROM AUTHOR]

Peas (Pisum sativum) are the fourth most cultivated pulses worldwide and a critical source of protein in animal feed and human food. Developing pea core collections improves our understanding of pea evolution and may ease the exploitation of their genetic diversity in breeding programs. We carefully selected a highly diverse pea core collection of 325 accessions and established their genetic diversity and population structure. DArTSeq genotyping provided 35,790 polymorphic DArTseq markers, of which 24,279 were SilicoDArT and 11,511 SNP markers. More than 90% of these markers mapped onto the pea reference genome, with an average of 2787 SilicoDArT and 1644 SNP markers per chromosome, and an average LD50 distance of 0.48 and 1.38 Mbp, respectively. The pea core collection clustered in three or six subpopulations depending on the pea subspecies. Many admixed accessions were also detected, confirming the frequent genetic exchange between populations. Our results support the classification of Pisum genus into two species, P. fulvum and P. sativum (including subsp. sativum, arvense, elatius, humile, jomardii and abyssinicum). In addition, the study showed that wild alleles were incorporated into the cultivated pea through the intermediate P. sativum subsp. jomardii and P. sativum subsp. arvense during pea domestication, which have important implications for breeding programs. The high genetic diversity found in the collection and the high marker coverage are also expected to improve trait discovery and the efficient implementation of advanced breeding approaches. [ABSTRACT FROM AUTHOR]

Habitat loss and fragmentation contribute significantly to the decline of arboreal mammal populations. As populations become fragmented and isolated, a reduction in gene flow can result in a loss of genetic diversity and have an overall impact upon long-term persistence. Creating wildlife corridors can mitigate such effects by increasing the movement and dispersal of animals, thus acting to reduce population isolation. To evaluate the success of a corridor, a before–after experimental research framework can be used. Here, we report the genetic diversity and structure of sugar glider (Petaurus breviceps) sampling locations within a fragmented landscape prior to the implementation of a wildlife corridor. This study used 5999 genome-wide SNPs from 94 sugar gliders caught from 8 locations in a fragmented landscape in south-eastern New South Wales, Australia. Overall genetic structure was limited, and gene flow was detected across the landscape. Our findings indicate that the study area contains one large population. A major highway dissecting the landscape did not act as a significant barrier to dispersal, though this may be because of its relatively new presence in the landscape (completed in 2018). Future studies may yet indicate its long-term impact as a barrier to gene flow. Future work should aim to repeat the methods of this study to examine the medium-to-long-term impacts of the wildlife corridor on sugar gliders, as well as examine the genetic structure of other native, specialist species in the landscape. [ABSTRACT FROM AUTHOR]

Research into the systematics of Prostanthera recently revealed close evolutionary relationship among P. phylicifolia sens. str. , the critically endangered P. gilesii , and a population of uncertain identity from the Central Tablelands of New South Wales (NSW), Australia. Previous analyses were unable to establish whether genetic boundaries separated these taxa. This study assessed species boundaries among these three taxa by using a combination of single-nucleotide polymorphisms (SNPs) sampled at the population-scale and multivariate analysis of morphological characters. Ordination, model-based clustering, F -statistics, neighbour-network analysis, phylogenetic analysis, and ancestry coefficient estimates all provided support for discrete genetic differences among the three taxa. Morphological phenetic analysis recovered congruent morphological clusters and identified a suite of corresponding diagnostic characters. This congruence of molecular and morphological evidence supports the presence of three independently evolving lineages, two of which correspond with the previously described P. gilesii and P. phylicifolia sens. str. The third taxon, represented by a single population from the Central Tablelands of NSW, is here described as P. volucris R.P.O'Donnell. A detailed description, diagnostic line drawings and photographs are provided. We evaluate P. volucris as satisfying criteria to be considered Critically Endangered. Recent molecular studies of Prostanthera (Lamiaceae) showed a close evolutionary relationship among P. phylicifolia s. str. , the critically endangered P. gilesii and a population of uncertain identity from New South Wales. In this study, analyses of genomic and morphological data identified the presence of three discrete entities that warrant specific recognition. A new species of immediate and critical conservation concern is identified, and methods for conservation are reviewed. [ABSTRACT FROM AUTHOR]