小麦骨干亲本繁6产量相关性状关键基因组区段的遗传效应

Genetic Effects of Key Genomic Regions Controlling Yield-Related Traits in Wheat Founder Parent Fan 6

繁6是中国小麦育种最重要的骨干亲本之一,明确其优良特性的遗传机制对小麦育种具有重要意义。本研究鉴定了39个繁6衍生品种的7个产量相关性状,并利用全基因组SSR标记分析了繁6中控制这些性状重要遗传区段和基因位点在子代中的遗传效应。表型鉴定结果表明,繁6产量相关性状在不同世代衍生品种中表现无显著差异,表明这些性状在衍生品种选育过程中受到选择并稳定遗传。利用已获得的控制小麦产量相关"一致性"QTL区段的417个SSR标记进行分子扫描,发现11个繁6特异SSR标记在其衍生后代中被高频率遗传。性状–标记关联分析表明,21个来自繁6的特异SSR标记与产量相关性状极显著关联(P<0.01)。同时鉴定出分别位于2A和5A染色体的Xgdm93.3–Xgwm526.2和Xbarc100–Xgwm156.1区段,前者控制株高和小穗数,后者控制千粒重。本研究证实,上述两个与小麦产量相关性状关联的位点或区段在小麦产量育种进程中受到强烈的人为定向连续选择,并在四川乃至西南麦区小麦产量育种中发挥了重要作用。

Fan 6 is an important wheat founder parent in China. A deep understanding on the genetic mechanism for excellent agronomic traits in Fan 6 will facilitate its utilization in wheat breeding. In this study, seven yield-related traits were investigated in Fan 6 and its 39 derived varieties and trait-associated chromosomal regions were scanned with genome-wide SSR markers. The traits investigated showed no significant differences between Fan 6 and its derived varieties, indicating that these traits have been subjected to directive selection and inherited stably from Fan 6 to its offspring. Out of the 417 SSR markers flanking loci for yield-related traits, 11 Fan 6-specific markers were detected frequently in its derived varieties. Trait–marker association analysis indicated that 21 Fan 6-specific markers were significantly associated with yield-related traits （P 〈 0.01）. Two chromosomal intervals, Xgdm93.3–Xgwm526.2 on 2A and Xbarc100–Xgwm156.1 on 5A, were identified to control plant height ＋ spikelet number per spike and thousand-kernel weight, respectively. The present study confirmed that the loci or chromosomal regions associated with yield-related traits are key factors for high yield and have been selected intensively and continuously during breeding process in Sichuan and even Southwest wheat zones.