Western Crop Genetics Alliance, Agricultural Sciences, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, Perth, WA, Australia.
Department of Primary Industries and Regional Development, Perth, WA, Australia.
Theor Appl Genet. 2022 Sep;135(9):3087-3102. doi: 10.1007/s00122-022-04169-x. Epub 2022 Jul 25.
Key genes controlling flowering and interactions of different photoperiod alleles with various environments were identified in a barley MAGIC population. A new candidate gene for vernalisation requirements was also detected. Optimal flowering time has a major impact on grain yield in crop species, including the globally important temperate cereal crop barley (Hordeum vulgare L.). Understanding the genetics of flowering is a key avenue to enhancing yield potential. Although bi-parental populations were used intensively to map genes controlling flowering, their lack of genetic diversity requires additional work to obtain desired gene combinations in the selected lines, especially when the two parental cultivars did not carry the genes. Multi-parent mapping populations, which use a combination of four or eight parental cultivars, have higher genetic and phenotypic diversity and can provide novel genetic combinations that cannot be achieved using bi-parental populations. This study uses a Multi-parent advanced generation intercross (MAGIC) population from four commercial barley cultivars to identify genes controlling flowering time in different environmental conditions. Genome-wide association studies (GWAS) were performed using 5,112 high-quality markers from Diversity Arrays Technology sequencing (DArT-seq), and Kompetitive allele-specific polymerase chain reaction (KASP) genetic markers were developed. Phenotypic data were collected from fifteen different field trials for three consecutive years. Planting was conducted at various sowing times, and plants were grown with/without additional vernalisation and extended photoperiod treatments. This study detected fourteen stable regions associated with flowering time across multiple environments. GWAS combined with pangenome data highlighted the role of CEN gene in flowering and enabled the prediction of different CEN alleles from parental lines. As the founder lines of the multi-parental population are elite germplasm, the favourable alleles identified in this study are directly relevant to breeding, increasing the efficiency of subsequent breeding strategies and offering better grain yield and adaptation to growing conditions.
在大麦 MAGIC 群体中鉴定出控制开花的关键基因和不同光周期等位基因与各种环境的相互作用。还检测到一个新的春化要求候选基因。开花时间的优化对包括全球重要的温带谷类作物大麦（Hordeum vulgare L.）在内的作物品种的籽粒产量有重大影响。了解开花的遗传学是提高产量潜力的关键途径。尽管双亲群体被广泛用于绘制控制开花的基因图谱，但它们缺乏遗传多样性，需要额外的工作来在选定的系中获得所需的基因组合，特别是当两个亲本品种不携带这些基因时。使用四个或八个亲本品种组合的多亲本作图群体具有更高的遗传和表型多样性，可以提供无法通过双亲群体获得的新的遗传组合。本研究使用来自四个商业大麦品种的多亲本高级世代互交（MAGIC）群体，鉴定不同环境条件下控制开花时间的基因。使用来自多样性阵列技术测序（DArT-seq）的 5112 个高质量标记进行全基因组关联研究（GWAS），并开发了 Kompetitive allele-specific polymerase chain reaction（KASP）遗传标记。连续三年从十五个不同的田间试验中收集表型数据。在不同的播种时间进行种植，并对植物进行春化和延长光周期处理。本研究在多个环境中检测到与开花时间相关的十四个稳定区域。GWAS 结合泛基因组数据突出了 CEN 基因在开花中的作用，并能够从亲本系中预测不同的 CEN 等位基因。由于多亲群体的原始系是优良的种质，因此本研究中鉴定的有利等位基因直接与育种相关，提高了后续育种策略的效率，并提供了更好的籽粒产量和对生长条件的适应能力。
