小麦不育系柱头外露特性的遗传与分子定位

More than ten heterotic hybrid wheat varieties have been released recently both in north and south of China. But for the mass application of hybrid wheat, the hybrid seed production is still a bottleneck. Researches and successful experiences in hybrid rice demonstrated that breeding sterile lines with good stigma exertion is one of the most economic and effective ways to break the bottleneck. But nothing is known about the genetic basis of stigma exertion in wheat sterile line, causing low efficiency in selection of this trait in practical breeding. In our previous observation, the stigma exertion in wheat thermo-photo-sensitive genic male sterile (TPSGMS) lines showed as a quantitative trait but with main effect loci, and we mapped one SSR marker wmc421 on chromosome 5B with the genetic distance at 25.2cM. In this project, we plan to use DH population derived from two TPSGMS lines K78S/C49S-87 to further map the genes concerned with wheat stigma exertion, where K78S has good stigma exertion while C49S-87 has not during more than ten years' observation. Firstly, try to finely map stigma exertion genes by SNP and EST markers, then estimate genetic effect of these markers to find out the main genes or QTLs controlling stigma exertion; Secondly, identified closely linked or Co-segregated markers of stigma exertion. The results will help to understand the genetic basis of stigma exertion in wheat TPSGMS lines, and provide powerful tool by MAS for creating more TPSGMS lines with better stigma exertion to further raise the efficiency of hybrid seed production.

近几年我国北方和南方麦区已育成审定十余个小麦强优势组合，但规模化制种产量偏低仍是目前制约杂交小麦大规模应用的一个瓶颈问题。选育柱头外露率高的小麦不育系是解决该问题的一个有效途径。目前国内外对小麦不育系柱头外露的遗传基础缺乏研究,导致育种中对该性状的选择具有偶然性且效率低。初步研究表明小麦温光敏雄性核不育系的柱头外露为数量性状且存在主效位点,找到一个SSR引物与其相关，位于5B染色体上，但遗传距离较远（25.2cM）。为此，本研究拟以小麦温光敏雄性核不育系K78S（柱头外露率较高）和 C49S-87（无柱头外露）杂交构建的DH群体为材料,利用SNP和EST标记对其进行更精细定位，找出控制小麦温光敏不育系柱头外露主效基因和与之紧密连锁或共分离的标记。研究结果对于认识小麦柱头外露的遗传规律、提高具柱头外露特性的优良不育系的创制效率、突破杂交小麦制种产量的技术瓶颈,都具有重要的理论和应用价值。

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