Soybean seed protein content (PC) and oil content (OC) have important economic value. Detecting the loci/gene related to PC and OC is important for the marker-assisted selection (MAS) breeding of soybean. To detect the stable and new loci for PC and OC, a total of 320 soybean accessions collected from the major soybean-growing countries were used to conduct a genome-wide association study (GWAS) by resequencing. The PC ranged from 37.8% to 46.5% with an average of 41.1% and the OC ranged from 16.7% to 22.6% with an average of 21.0%. In total, 23 and 29 loci were identified, explaining 3.4%–15.4% and 5.1%–16.3% of the phenotypic variations for PC and OC, respectively. Of these, eight and five loci for PC and OC, respectively, overlapped previously reported loci and the other 15 and 24 loci were newly identified. In addition, nine candidate genes were identified, which are known to be involved in protein and oil biosynthesis/metabolism, including lipid transport and metabolism, signal transduction, and plant development pathway. These results uncover the genetic basis of soybean protein and oil biosynthesis and could be used to accelerate the progress in enhancing soybean PC and OC.

Processing quality is an important economic wheat trait. The marker-assisted selection (MAS) method plays a vital role in accelerating genetic improvement of processing quality. In the present study, processing quality in a panel of 165 cultivars grown in four environments was evaluated by mixograph. An association mapping analysis using 90 K and 660 K single nucleotide polymorphism (SNP) arrays identified 24 loci in chromosomes 1A, 1B (4), 1D, 2A, 2B (2), 3A, 3B, 3D (2), 4A (3), 4B, 5D (2), 6A, 7B (2) and 7D (2), explaining 10.2–42.5% of the phenotypic variances. Totally, 15 loci were stably detected in two or more environments. Nine loci coincided with known genes or QTL, whereas the other fifteen were novel loci. Seven candidate genes encoded 3-ketoacyl-CoA synthase, lipoxygenase, pyridoxal phosphate-dependent decarboxylase, sucrose synthase 3 and a plant lipid transfer protein/Par allergen. SNPs significantly associated with processing quality and accessions with more favorable alleles can be used for marker-assisted selection.

Common vetch (Vicia sativa L.) is a globally green manure and forage crop, cultivated extensively worldwide. Its seeds serve as an important concentrated feed. Due to the late release of the reference genome, few studies were conducted to analyze the genetic mechanisms of grain yield, which hindered the progress of common vetch breeding. Marker-assisted selection (MAS) is the best and most effective way to accelerate the genetic improvement of grain yield-related traits in common vetch. In this study, we performed a genome-wide association study (GWAS) using the high-density single nucleotide polymorphism (SNP) data obtained through re-sequencing to better understand the genetic basis of grain yield-related traits. In total, six grain yield-related traits were evaluated in 172 accessions mainly sourced from China and Russia, across four environments, including branches per plant (NB), pod length (PL), number of pods per plant (NP), number of grains per pod (NG), hundred-grain weight (HGW), and grain yield (GY). Population structure analysis of the 172 accessions revealed four distinct subpopulations, exhibiting strong geographical correlation. In total, 38 loci have been identified as significantly associated with six grain yield-related traits, accounting for 13.3–31.7% of the phenotypic variances. Among them, qGY1.1 and qNG1.1, qNG2.2 and qPL2.1, qNG3.2 and qGY3.2, qNG4.1 and qPL4.1, qGY4.1 and qHGW4.1, qNG6.1 and qPL6.1, and qNB6.2 and qGY6.2 exhibit overlapping regions, suggesting that these regions are pleiotropic and should be prioritized for further research and breeding. In total, 12 candidate genes encoding auxin response factor, F-box repeat protein, gibberellin receptor, serine/threonine-protein kinase-like protein, and cellulose synthase-like protein were identified. Furthermore, we successfully developed and verified a kompetitive allele-specific PCR (KASP) marker (Kasp-NB6.2) for the number of branches. These findings provide molecular insights into grain yield-related traits in common vetch and offer valuable loci and molecular tools for MAS breeding.

The dissection of the genetic architecture and the detection of the loci for adaptive traits are important for marker-assisted selection (MAS) for breeding. A spring wheat diversity panel with 251 cultivars, mainly from China, was obtained to conduct a genome-wide association study (GWAS) to detect the new loci, including the heading date (HD), maturating date (MD), plant height (PH), and lodging resistance (LR). In total, 41 loci existing in all 21 chromosomes, except for 4A and 6B, were identified, and each explained 4.3–18.9% of the phenotypic variations existing in two or more environments. Of these, 13 loci are overlapped with the known genes or quantitative trait loci (QTLs), whereas the other 28 are likely to be novel. The 1A locus (296.9–297.7 Mb) is a multi-effect locus for LR and PH, whereas the locus on chromosome 6D (464.5–471.0 Mb) affects both the HD and MD. Furthermore, four candidate genes for adaptive traits were identified, involved in cell division, signal transduction, and plant development. Additionally, two competitive, allele-specific PCR (KASP) markers, Kasp_2D_PH for PH and Kasp_6D_HD for HD, were developed and validated in another 162 spring wheat accessions. Our study uncovered the genetic basis of adaptive traits and provided the associated SNPs and varieties with more favorable alleles for wheat MAS breeding.

Elymus sibiricus, valued for its perennial nature, broad adaptability, strong cold tolerance, and high economic value in forage production, plays a crucial role in combating grassland degradation, desertification, and salinization. Using morphological and cytogenetic methods, this study evaluated the cold tolerance, post-harvest regeneration capacity, and perennial characteristics of the E. sibiricus accession 20HSC-Z9 in the Harbin region of China from 2020 to 2023. This accession exhibited a germination rate of over 90% and a 100% green-up rate, with purple coleoptiles indicating its strong cold tolerance. Over the three growing seasons, 20HSC-Z9 maintained stable green-up and regeneration rates, confirming its perennial nature. Morphologically, 20HSC-Z9 had an average tiller count ranging from 56 to 74, similar to that of the control accession 20HSC-ES, and its plant height was significantly lower than that of 20HSC-IWG. Furthermore, 20HSC-Z9 produced over 100 grains per spike, with a seed setting rate exceeding 90%, and a thousand-grain weight comparable to that of 20HSC-IWG. The grain protein content of 20HSC-Z9 reached a maximum of 21.19%, greater than that of the control accessions (15.6% and 18.5%). Chromosome composition analysis, using sequential multicolor genomic in situ hybridization and multicolor fluorescence in situ hybridization, confirmed the StStHH genomic constitution of 20HSC-Z9 and revealed translocations between the St and H subgenome chromosomes. These results suggest that 20HSC-Z9 has significant potential as a new perennial forage grass germplasm for cold regions, suitable for further domestication and breeding efforts.

Background/Objectives: Common vetch (Vicia sativa L.) is a globally cultivated leguminous crop, valued for its high nutritional content and role in sustainable agriculture. Methods: To identify loci or genes significantly associated with salt tolerance, we conducted a genome-wide association study (GWAS) using 172 common vetch accessions primarily from diverse geographic regions. Single-nucleotide polymorphisms (SNPs) were obtained through re-sequencing, and five salt tolerance-related traits, including the germination rate (GR), germination potential (GP), germination index (GI), shoot length (SL), and root length (RL), were evaluated under salt stress conditions. We have identified 20 loci significantly associated with salt tolerance-related traits, and explaining 9.7–21.8% of the phenotypic variation. Notably, 13 loci exhibited pleiotropic effects on multiple traits; include qST1.1 (associated with SL, GR, GI), qST1.3 (RL, SL, GP), qST2.5 (SL, GR, GI, GP), and qST2.7 (SL, RL, GP, GI), and should be prioritized in future breeding programs. All 20 loci are novel compared to previous reports. Furthermore, we identified 7 candidate genes encoding key regulatory proteins, including a zinc finger MYM-type protein, ubiquitin-like domain-containing protein, transcription factor bHLH, ethylene-responsive transcription factor, auxin-responsive protein, and serine/threonine-protein kinase, as potential regulators of salt tolerance. Conclusions: This study advances our understanding of the genetic basis of salt tolerance in common vetch and provides valuable loci, molecular tools, and elite accessions. HZMC1352, GLF303, GLF301, HZMC1387, GLF306, GLF368, GLF342, HZMC1384, HZMC1355, GLF307, HZMC1366 are used for improving salt tolerance in breeding programs.