Genetic Diversity, Population Structure, and Linkage Disequilibrium in U.S. Elite Winter Wheat
Genetic Diversity, Population Structure, and Linkage Disequilibrium in U.S. Elite Winter Wheat
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DOI：
10.3835/plantgenome2010.03.0004
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发表时间：
2010-09
期刊：
影响因子：
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通讯作者：
Dadong Zhang;G. Bai;Chengsong Zhu;Jianming Yu;B. Carver
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文献类型：
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作者：
Dadong Zhang;G. Bai;Chengsong Zhu;Jianming Yu;B. Carver
小麦优良品种的遗传多样性和群体结构研究育种系促进了遗传资源的有效利用。我们使用245个小麦基因组标记分析了来自美国主要冬小麦育种计划的205个优良小麦育种系。每个位点的等位基因数（7.2）和多态性信息含量（0.54）反映了该集合显示出高水平的遗传多样性。然而，美国现代小麦的多样性似乎低于以前报道的全球种质资源的多样性水平。正如预期的那样，这个集合是根据地理来源和市场等级高度结构化的，软小麦和硬小麦彼此明显分开。硬粒小麦可进一步分为3个亚群。连锁不平衡（LD）主要分布在着丝粒区域。平均全基因组LD衰减估计值为10 cM（r2 > 0.1），尽管LD的程度在整个基因组中高度可变。我们对不同基因库的遗传多样性和LD分布的研究结果有助于小麦遗传资源的有效利用和基因定位及标记辅助育种中标记密度的选择。
Information on genetic diversity and population structure of elite wheat (Triticum aestivum L.) breeding lines promotes effective use of genetic resources. We analyzed 205 elite wheat breeding lines from major winter wheat breeding programs in the USA using 245 markers across the wheat genomes. This collection showed a high level of genetic diversity as reflected by allele number per locus (7.2) and polymorphism information content (0.54). However, the diversity of U.S. modern wheat appeared to be lower than previously reported diversity levels in worldwide germplasm collections. As expected, this collection was highly structured according to geographic origin and market class with soft and hard wheat clearly separated from each other. Hard wheat accessions were further divided into three subpopulations. Linkage disequilibrium (LD) was primarily distributed around centromere regions. The mean genome‐wide LD decay estimate was 10 cM (r2 > 0.1), although the extent of LD was highly variable throughout the genome. Our results on genetic diversity of different gene pools and the distribution of LD facilitates the effective use of genetic resources for wheat breeding and the choice of marker density in gene mapping and marker‐assisted breeding.