1BL/1RS易位对小麦产量性状和白粉病抗性的影响及其QTL分析

Effect of 1BL/1RS Translocation on Yield Traits and Powdery Mildew Resistance in Common Wheat and QTL Analysis

用PH82-2／内乡188杂交后代240个R5：6家系，按照α-lattice设计，分别种植在安阳、焦作和泰安，对产量和抗白粉病等性状进行了考察。利用SSR和蛋白标记对群体进行部分连锁作图，分析1BL／1RS易位对产量及其相关性状的遗传效应。结果表明，1BL／1RS易位系对产量、穗数／m^2和抽穗期的影响不显著；易位系的千粒重和白粉病抗性显著高于非易位系，但株高和穗粒数减少。利用复合区间作图法进行QTL分析，发现1RS携带1个降低株高的微效QTL，位于HVM20～Sec—1标记区间，可解释4．28％的表型变异；1Rs和1BL携带抗白粉病QTL，分别位于HVM20～Sec—1和Xgwm24～Xwmc320标记区间，解释4．81％和4．66％的表型变异。鉴于1BL／1RS易位对产量的正向作用不明显，其主效抗性已丧失。又对加工品质有明显的负向影响，在小麦品质育种上最好不予应用。

The 1BL/1RS translocation has been widely used by wheat breeders to enhance agronomic performance and disease resistance. The objective of this study was to analyze the genetic effect of 1BL/1RS translocation on yield traits and powdery mildew resistance in common wheat. A total of 240 F5：6 lines from the cross PH82-2/Neixiang 188 were planted with a latinized alpha-lattice design in Anyang and Jiaozuo of Henan Province and Tai＇ an of Shandong Province, respectively. Grain yield, thousand-grain weight, grain number per spike, spike number, plant height, heading date, and powdery mildew severity were investigated in field trials. Fourteen SSR and storage protein markers on chromosome 1BL/ 1RS were used to analyze the population and construct a linkage map. QTL analysis was conducted with the software QTL Cartographer 2.5. A significantly higher thousand-grain weight, reduced grain number per spike and plant height, and lower powdery mildew severity in 1BL/1RS translocation lines were observed, whereas no significant difference was observed in grain yield, spike number and heading date between 1BL/I RS and 1B/1 B lines. With the method of composite interval mapping （CIM）, the putative QTLs of plant height and powdery mildew resistance were detected on 1BL/1RS translocation segment across three environments. A QTL in the interval of HVM20-See-1 was detected for reducing plant height on 1BL/ 1RS translocation segment explaining 4.28 % of the phenotypic variation. Two QTLs for powdery mildew resistance were found on 1BL/1RS translocation segment （HVM20-Sec-1 ） and 1BL （Xgwm24-Xwmc320）, accounting for 4.81% and 4.66 % of phenotypic variance, respectively. The QTL for powdery mildew resistance on 1BL/1RS transloeation segment may be the residual effect of Pro8. From breeding point of view, 1BL/1RS translocations are generally not recommended inyield and quality wheat breeding at present, due to its inconsistent contribution to yield, lost resistance to disease and negative effect on quality.