基于全基因组扫描的白皮小麦抗穗发芽关联分析

Preharvest Sprouting (PHS) is one of the major damage problems in wheat production. In China, 83% of wheat planting region was damaged by PHS. It is not only decrease quantity, but also great decrease quality of grain in wheat. Because of white-kernelled wheat produce much more flour than red-kernelled wheat, attracting many flourmill and farmers to cultivate white-kernelled wheat result in the cultivated area of white-kernelled wheat continue growth in recent years. But white-kernelled wheat usually had much more weak seed dormancy than the red-kernelled wheat, so this circumstance had already grave threaten the wheat production. In this study, based on assessing the resistance of PHS of 500 white-kernelled wheats and whole genome scan by SSR markers and Genotyping By Sequencing, we will use the linkage disequilibrium mapping method to depth explore new PHS resistance genes in white-kernelled wheat. Forward, we will develop the functional markers for breeding resistance white-kernelled wheat varieties.

穗发芽是小麦生产上重要的自然灾害之一。我国是穗发芽危害频繁和严重的地区，受穗发芽危害的麦区约占全国小麦总面积的83%。穗发芽不仅降低产量而且严重劣化品质(尤其是加工品质)和种用价值。白皮小麦品种由于出粉率高，受到面粉加工企业和农户的青睐，种植面积不断提高，但因其休眠期短，易穗发芽，已严重威胁当今小麦生产。因此，发掘白皮小麦的抗穗发芽基因资源迫在眉睫。本项目在对500余份白皮小麦抗穗发芽及休眠基因资源的鉴定、评价的基础上，拟结合经典SSR标记及前沿基因组测序（Genotyping By Sequencing 策略）技术扫描白皮小麦资源全基因组，采用基于连锁不平衡的关联分析方法大规模的深度挖掘白皮小麦中的新抗性基因，并开发相应功能分子标记，为改良白皮小麦穗发芽抗性提供理论基础和基因资源。

通过对白皮小麦材料穗发芽表型数据整理分析，鉴定了其穗发芽抗性和休眠性状，筛选出4份抗穗发芽材料。利用SSR标记、GBS标记对白皮小麦材料进行全基因组关联分析，检测到24个显著关联的位点。根据筛选获得的候选基因（位点），开发了2对白皮小麦抗穗发芽相关的分子标记，为创制优异的白皮、抗穗发芽新材料/新品系奠定了基础。在此基础上，进一步深入分析了穗发芽相关基因TaAmy3等位变异，为培育抗穗发芽白皮小麦提供优异等位基因。