陆地棉VR018抗黄萎病QTL定位

Quantitative trait locus mapping for Verticillium wilt resistance in upland cotton VR018

黄萎病是棉花生产中的主要病害。由于陆地棉中严重缺乏高抗黄萎病的品种,棉花抗黄萎病育种研究进展缓慢。本研究室从泗棉3号与中植棉2号杂交后代中选育获得1个黄萎病抗性显著提高的新品系苏VR018,利用3 100对SSR引物对泗棉3号和苏VR018进行多态性分析,获得具有多态性的标记32个;以苏VR018为母本,泗棉3号为父本,杂交构建包含312个单株的F2群体,构建包含17个位点和6个连锁群的连锁图谱。F2∶3家系接种落叶型黄萎病菌V991,调查抗病性,通过复合区间作图法共检测到4个与棉花抗黄萎病相关的QTL,分别位于染色体A5、染色体D5、染色体D5和染色体D6染色体上,表型贡献率分别为6. 41%、3. 78%、4. 61%和5. 78%。单标记分析检测到与黄萎病抗性显著关联的位点5个,分别为NAU3212、MGHES40、DPL209、CIR181和NAU5204,解释表型变异分别为6. 38%、1. 50%、2. 80%、2. 10%和2. 20%。本研究为深入解析中植棉2号的抗黄萎病遗传机制奠定了理论基础。

Verticillium wilt(VW)is one of the most crushing diseases in cotton production.Due to the lack of varieties with high resistance to Verticillium dahliae(V.dahliae)in upland cotton,the progress of disease resistance breeding was slow.We acquired a resistance line,SuVR018 with the higher resistance to V.dahliae,which was selected from F 2 segregated population crossing by Simian 3 and Zhongzhimian 2.In this study,3 100 pairs of SSR primers were used to detect polymorphism of SuVR018 and Simian 3,and 32 SSR markers with polymorphism were identified.Using SuVR018 as female parent and Simian 3 as male parent,the F 2 population with 312 individual plants was constructed by hybridization,and the linkage map with 17 polymorphic loci six linkage groups was constracted.In order to investigate the resistance to V.dahliae strain V991,F 2∶3 families were inoculated.Four QTLs related to V.dahliae were detected on Chr.A5,Chr.D5,Chr.D5 and Chr.D6,and the phenotypic contribution rates were 6.41%,3.78%,4.61%and 5.78%,respectively.With association analysis,five loci associated with VW resistance were detected,which were NAU3212,MGHES40,DPL209,CIR181 and NAU5204,and explained 6.38%,1.50%,2.80%,2.10%and 2.20%of the phenotypic variation,respectively.These results lay a theoretical foundation for further analysis of the resistant mechanism to VW in Zhongzhimian 2.