小麦重要品质性状的QTL定位

QTL Mapping for Important Quality Traits in Common Wheat

【目的】发掘重要性状的QTL及其分子标记进行小麦品质分子改良。【方法】采用PH82-2/内乡188杂交后代240个F5:6家系,按照Latinizedα-lattice设计,2004～2005年度分别种植在河南焦作、安阳和山东泰安。对籽粒蛋白质含量、Zeleny沉降值、和面时间、8分钟带宽、峰值粘度和稀懈值进行测定,利用188个SSR标记和4个蛋白标记构建遗传连锁图谱,采用复合区间作图法(CIM)对上述6个品质性状进行QTL定位。【结果】籽粒蛋白质含量检测出3个QTL,分布在3A、3B染色体上。在1B、1D和3B染色体上检测到3个控制Zeleny沉降值的QTL,其中位于1B和1D染色体上的QTL在3个地点均检测到,可解释5.5%～17.6%表型变异。发现3个控制和面时间的QTL,分布在1B和1D染色体上,在3个地点均能检测到,贡献率为7.9%～55.3%;检测出8分钟带宽的QTL5个,其中1B和1D染色体上的QTL在3种环境下均能检测到,贡献率为11.7%～33.9%。发现峰值粘度QTL4个,分布在1A、1B、3A和7B染色体上;检测出稀懈值QTL5个,位于1B、4A、5B、6B和7A染色体上。1B染色体上存在同时控制Zeleny沉降值、和面时间、8分钟带宽、峰值粘度和稀懈值的QTL,与最近标记Glu-B3j连锁距离为0.1～0.8cM,说明1BL/1RS易位对这些性状有重要影响;1D染色体上存在同时控制Zeleny沉降值、和面时间和8分钟带宽的QTL,与最近的标记Dx5+Dy10连锁距离为2.5～3.3cM,表明Dx5+Dy10高分子量谷蛋白亚基对这3个性状影响很大。和面时间和8分钟带宽位于1B和1D染色体的QTL以及稀懈值位于1B染色体上的QTL在3个地点均能检测到,具有环境稳定性。【结论】本研究定位的品质性状的标记可作为小麦品质分子育种的工具。

【Objective】 QTL for wheat processing quality traits and their linked molecular markers are to be identified for wheat quality improvement with marker-assisted selection. 【Method】In the present study, a total of 240 F5：6 lines from the cross PH82-2/Neixiang 188 were planted in a Latinized alpha-lattice design in Jiaozuo and Anyang of Henan Province and Taian of Shandong Province, respectively. Grain protein contents, Zeleny sedimentation value, Mixograph and RVA parameters were evaluated. A genetic map was constructed based on 188 SSRs and four protein markers. QTL analysis was conducted with the software QTL Cartographer 2.5. 【Result】 Three QTLs were detected for kernel protein content on chromosomes 3A and 3B. Three QTLs were found for Zeleny sedimentation value on chromosomes 1B, 1D and 3B, in which the QTLs on chromosome 1B and 1Dwere detected across three environments, explaining 5.5%-17.6% of phenotypic variance. Three QTLs for mixing time were mapped on chromosomes 1B and 1D across three environments, accounting for 7.9%-55.3% of phenotypic variance. Five QTLs were detected for eight minute width on chromosomes 1B, 1D and 4B. Besides, two QTLs on chromosome 1B were found both in Taian and Anyang, accounting for 5.2%-18.6% of phenotypic variance. Four QTLs for peak viscosity were detected on chromosomes 1A, 1B, 3A and 7B. Five QTLs for breakdown were found on chromosomes 1B, 4A, 5B, 6B and 7A. The QTLs controlling Zeleny sedimentation value, mixing time, eight minute width, peak viscosity and breakdown were mapping on the same region of chromosome 1B, with genetic distances of 0.1-0.8 cM from the nearest marker Glu-B3j, indicating the big influences of 1BL/1RS translocation on these traits. In addition, on chromosome 1D, one QTL was found to control the Zeleny sedimentation value, mixing time and eight minute width, with genetic distances of 2.5-3.3 cM from the nearest marker Dx5＋Dy10, exhibiting a great effect of HMW glutenin subunits Dx5＋Dy10 on these traits. The QTLs for mixing time and breakdown on chromosome 1B, and the one for eight minute width on chromosome 1D were detected across three environments, with stable effects on the traits. 【Conclusion】The identified molecular markers related to the quality traits in this study will benefit for marker-assisted selection in breeding programs.