大豆抗筛豆龟蝽Megacota cribraria(Fabricius)的QTL分析

Mapping QTLs of Resistance to Megacota cribraria (Fabricius) in Soybean

筛豆龟蝽是我国南方大豆的主要害虫之一,本研究旨在定位筛豆龟蝽抗性QTL,分析其稳定性,为大豆抗筛豆龟蝽育种提供参考。以科丰1号×南农1138-2组合衍生的含184个重组自交系的群体NJRIKY（简称KY）和皖82-178×通山薄皮黄豆甲组合衍生的含142个重组自交系的群体NJRIWT（简称WT）为材料,2004-2006在田间自然虫源下鉴定了筛豆龟蝽抗性。不同年份内以黑霉程度为指标的方差分析结果表明家系间差异在每年都达极显著水平,遗传变异系数都相当大,遗传率中等偏高。利用Windows QTL Cartographer Version2.5的复合区间作图法（CIM）,KY群体的抗性QTL主要位于D1a和C2连锁群,WT群体的抗性QTL主要位于H和D1b连锁群。KY群体3年均检测出的qRMC-d1a-1位于D1a连锁群,贡献率为7.6%～31.4%;2005和2006两年均检测出的qRMC-c2-1位于C2连锁群,与环境有互作,效应相对较小;抗性等位基因来自南农1138-2;qRMC-d1a-1和qRMC-h-1在2005年和2006年存在显著的互作。WT群体连锁群H上的qRMC-h-1在3年中都被检测到,贡献率为16.3%～36.2%;D1b连锁群上的qRMC-d1b-2在2004年和2005年被检测到,效应相对较小;抗性等位基因来自通山薄皮黄豆甲。虽然WT群体D1b和H连锁群上的这2个QTL在KY群体中也有一年被检测到,但2个群体抗性位点基本上是不同的。QTL在不同环境被重复检出,说明大豆对筛豆龟蝽的抗性由稳定的主效QTL所控制,其2侧邻近标记有希望用于标记辅助选择育种。

Globular stink bug [Megacota cribraria （Fabricius）] is one of the important pests for soybean [Glycine max （L.） Merr.] in the central and southern China. However, very few reports on soybean resistant to M. cribraria were found in the literature. The objectives of the present study were to find QTLs associated with resistance to M. cribraria in soybean and to analyze the stability of mapped QTLs among years by using two RIL populations, NJRIKY （or KY） and NJRIWT （or WT） derived from the crosses of Kefeng 1 × Nannong 1138-2 and Wan 82-178 × Tongshanbopihuangdoujia, respectively. The 184 lines of KY and 142 lines of WT were tested and the percentage of black mildew on stem and purple spots on leaves was used as indicator to evaluate their resistance to M. cribraria under natural infestation during 2004–2006. There existed significant differences among lines in the two RIL populations during the three years, with heritability of 66.5%–88.8% in KY and 61.3%–84.8% in WT. The composite interval mapping （CIM） of the software Windows QTL Cartographer Version 2.5 was used to map QTLs. The linkage group D1a and C2in KY and the linkage group H and D1b in WT were found to be related with resistance to M.crubrarua. The QTL qRMC-d1a-1 on Linkage group D1a was detected consistently associated with reaction to M. cribraria in KY during the three years, which accounted for 7.6%–31.4% of phenotypic variation; the QTL qRMC-c2-1 on linkage group C2 was detected in 2005–2006, which accounted for less phenotypic variation than the former one; the resistance alleles were from Nannong 1138-2. There appeared significant interactions between qRMC-d1a-1 and qRMC-h-1 in KY in 2005 and 2006. The QTL qRMC-h-1 on linkage group H was detected also consistently associated with reaction to M. cribraria in WT during the three years, which accounted for 16.3%–36.2% of phenotypic variation; the QTL qRMC-d1b-2 on linkage group D1b was detected in 2004-2005, which accounted for less phenotypic variation than the former one; the resistant alleles were from Tongshanbopihuangdoujia. Therefore, different QTLs conferred resistance to M. cribraria in KY and WT basically although the two QTLs in the latter population were also identified in one year in the former population. The fact that the QTLs were repeatedly detected in different environments indicated the resistance was controlled stably by the main QTLs. Based on the results, it is inferred that the markers linked to the detected QTLs should be useful for marker-assisted selection for resistance to M. cribraria in soybean.