中品03-5373对大豆胞囊线虫3号生理小种免疫抗性的遗传解析

大豆胞囊线虫3号生理小种在我国已发现的8个小种中分布最为广泛,严重影响大豆生产。中品03-5373(ZP03-5373)是对3号小种免疫的优良抗源。本研究以中品03-5373为母本,与感病品种中黄13(ZH13)杂交建立包含254个家系的重组自交系群体,利用SSR、EST-SSR、In Del和SNP等506个分子标记对该分离群体进行基因型鉴定,构建全长为2651.90 c M的遗传图谱,标记间平均距离为5.24 c M。结合抗性鉴定数据,在中品03-5373中检测到3个控制大豆胞囊线虫3号生理小种的QTL区间,分别位于Gm07(SCN3-7)、Gm11(SCN3-11)和Gm18(SCN3-18)。其中SCN3-18可解释29.5%的抗性变异,为主效抗性位点;SCN3-7和SCN3-11分别控制6.2%和5.5%的抗性变异,为微效位点。SCN3-7与SCN3-18间存在显著的上位性互作。通过对中品03-5373祖先亲本2个QTL区间(SCN3-7和SCN3-11)侧翼标记的系谱追踪,进一步证明SCN3-7和SCN3-11与大豆胞囊线虫3号抗性相关。

Genetic Analysis of Immunity to Soybean Cyst Nematode Race 3 in Elite Line Zhongpin 03-5373

Soybean cyst nematode (SCN) race 3, one of the eight races identified in China, is widely distributed and severely reduced soybean yield. Zhongpin 03-5373 (ZP03-5373) is an elite line immune to SCN race 3. In this study, a recombinant inbred line (RIL) population was developed from a cross between ZP03-5373 and Zhonghuang 13 (ZH13). A genetic linkage map was constructed using a total of 506 molecular markers, including SSRs, EST-SSRs, InDel, and SNP. The total length of the genetic map was 2651.9 cM with an average marker spacing of 5.24 cM. Based on the phenotyping data, we detected three QTL intervals to dominate SCN3, including SCN3-7 (Gm07), SCN3-11 (Gm11), and SCN3-18 (Gm11). Main effect QTL, SCN3-18 could explain 29.5% of resistant variation. Two minor effect QTLs, SCN3-7 and SCN3-11, explained 6.2% and 5.5% of resistant variation, respectively. And it further showed there was significant epistatic interaction between SCN3-7 and SCN3-18 for resistance to SCN3. Both SCN3-7 and SCN3-11 were confirmed to be resistant to SCN3 by tracking flanking marker in the ancestors of ZP03-5373. These markers will be helpful for developing SCN resistant cultivars and cloning resistant genes by marker assisted selection.