小麦燕大1817×北农6号重组自交系群体在正常和盐胁迫水培条件下苗期性状的QTL定位

Mapping QTLs for Wheat Seedling Traits in RILs Population of Yanda 1817 × Beinong 6 under Normal and Salt-Stress Conditions

小麦苗期性状能够指示品种的耐盐性。本研究以小麦骨干亲本燕大1817与品系北农6号衍生的230个重组自交系为材料,利用2013年3个不同时间的水培试验数据和已经构建的SSR和SNP高密度遗传连锁图谱分别对正常和盐胁迫条件下根数和最长根长等7个苗期性状进行QTL定位。利用完备复合区间作图法（ICIM）共检测到69个加性效应QTL（LOD≥2.5）,分布于除1A染色体外的所有20条染色体上,单个QTL解释的表型变异率为2.70%~19.00%。有46个QTL的增效效应来自于燕大1817,有23个QTL的增效效应来自于北农6号。有12个QTL能够在3个或3个以上的环境中被检测到,在燕大1817中定位到稳定的多分蘖主效QTL QTn.cau-7BS.1和盐胁迫条件下特异表达的根数QTL QRn.cau-2A,解析了小麦骨干亲本燕大1817的繁茂性和抗逆性遗传基础,为解析小麦品种耐盐遗传机制和耐盐性的分子标记辅助选择提供了重要信息。

Seedling traits are known to be important indicators loci （QTLs） mapping for wheat seedling traits under salt stress of salt tolerance in wheat （Triticum aestivum L.）. Quantitative trait and normal hydroponics conditions were conducted at three times during 2013 using a set of 230 recombinant inbred lines （RILs） derived from a cross of Yanda 1817 x Beinong 6 and an available high-density integrated SSR and SNP genetic linkage map. A total of 69 putative QTLs associated with seven seedling traits were detected on 20 chromosomes except for 1A by inclusive composite interval mapping （ICIM） at LOD 〉 2.5. A single QTL ex- plained 2.70-19.00% of the phenotypic variation. Of which, 46 QTLs showed additive effects originated from Yanda 1817, whereas 23 QTLs showed additive effects derived from Beinong 6, indicating that the founder parent Yanda 1817 is an important genetic resource for salt tolerance in wheat. Twelve QTLs are considered to be stable QTLs because they were detected in at least three environments, including the major QTL QTn.cau-7BS.I for tiller number and the salt-induced QTL QRn.cau-2A for root number, both originating from Yanda 1817. These results may explain the genetic bases of luxuriant growing habit and stress tol- erance of Yanda 1817.