Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
Ethiopian Institute of Agricultural Research, P.O. Box 2003, Addis Ababa, Ethiopia.
Plant Genome. 2020 Nov;13(3):e20055. doi: 10.1002/tpg2.20055. Epub 2020 Sep 17.
Understanding population genetic structure and diversity of a crop is essential in designing selection strategies in plant breeding. About 2010 Ethiopian sorghum accessions were phenotyped for different traits at multiple locations. A subset of the collection, 1628 accessions, predominantly landraces, some improved varieties, and inbred lines were genotyped by sequencing. Phenotypic data revealed association of important traits with different sorghum growing agro-climatic regions, high genetic diversity and the presence of rare natural variation in the Ethiopian sorghum germplasm. Subsequent genotypic analysis determined optimum number of sub-populations, distinct cluster groups and ancestries of each sorghum accessions. To improve utilization of germplasm, a core subset of 387 lines were selected following posteriori grouping of genotypes based on cluster groups obtained through GBS analysis followed by stratified random sampling using quantitative traits. In order to evaluate how well this new sorghum and millet innovation lab (SMIL) collection from Ethiopia is represented within the largest world sorghum collection at United States Department of Agriculture - National Plant Germplasm System (USDA-NPGS) and the sorghum association panel (SAP), comparisons were conducted based on SNP data. The SMIL collection displayed high genetic diversity with some redundancy with the USDA-NPGS germplasm but SAP showed clear distinction. Furthermore, genome-environment association analysis identified candidate genes associated with adaptation to abiotic factors, that will be important for exploitation of adaptive potential to different environments. In summary, our results described the diversity and relationship of sorghum collections, representativeness of developed core and provide novel insights into candidate genes associated to abiotic stress tolerance.
了解作物的群体遗传结构和多样性对于植物育种中的选择策略设计至关重要。大约 2010 年，埃塞俄比亚高粱品种在多个地点对不同性状进行了表型鉴定。该品种集合的一个子集，即 1628 个品种，主要是地方品种、一些改良品种和自交系，通过测序进行了基因型鉴定。表型数据显示，重要性状与不同的高粱种植农业气候区相关，埃塞俄比亚高粱种质中存在高度遗传多样性和罕见的自然变异。随后的基因型分析确定了每个高粱品种的最佳亚群体数量、不同聚类群体和祖源。为了提高种质的利用效率，根据基于 GBS 分析获得的聚类群体对基因型进行事后分组，然后使用数量性状进行分层随机抽样，选择了 387 个核心品种。为了评估埃塞俄比亚新的高粱和小米创新实验室（SMIL）收集品在美国农业部 - 国家植物种质系统（USDA-NPGS）和高粱协会面板（SAP）中最大的世界高粱收集品中的代表性，根据 SNP 数据进行了比较。SMIL 收集品显示出高度的遗传多样性，与 USDA-NPGS 种质有一定的冗余，但 SAP 显示出明显的区别。此外，全基因组-环境关联分析鉴定出与非生物因素适应相关的候选基因，这对于利用不同环境的适应潜力非常重要。总之，我们的研究结果描述了高粱品种的多样性和关系、核心品种的代表性，并提供了与非生物胁迫耐受性相关的候选基因的新见解。
