基于新遗传连锁图谱的豇豆抗豆象QTL定位

【目的】豆象是危害豇豆最主要的仓储害虫。发掘豇豆抗豆象基因为抗性品种的选育,以及减少豆象对豇豆生产的危害奠定基础。【方法】以中豇1号（感）和Pant-lobia-1（抗）为亲本构建的包含282个株系的RIL群体为研究材料,利用人工接种法分别对282个株系接种绿豆象和四纹豆象,进行抗豆象表型鉴定,并利用两亲本对3 992个来源于绿豆、小豆和豇豆的SSR标记进行多态性筛选,然后利用筛选到的多态性标记对282个株系进行基因型分析,最后结合RIL群体各株系抗豆象表型鉴定数据和基因型分型数据,采用完备区间作图法（ICIM-ADD）进行抗豆象QTL定位分析,在此基础上构建遗传连锁图谱,并定位豇豆抗豆象基因。【结果】中豇1号和F₁籽粒的被害率均为100%,Pant-lobia-1籽粒的被害率分别为22.5%和42.5%。推测Pant-lobia-1对绿豆象和四纹豆象的抗性均为隐性遗传;筛选到182个多态性标记,利用这些多态性标记构建了一个包含11个连锁群的豇豆遗传连锁图谱,图谱总长1 065.23 cM,相邻标记间平均遗传距离为5.85 cM;经2种豆象处理,分别在连锁群1和连锁群5上检测到2个稳定的QTL位点,暂定名为vubr1-1和vubr5-1,其中vubr1-1位于标记XD11-44和HAAS_VR_2274之间,标记间的遗传距离为7.6 cM,在2种豆象处理中分别可以解释表型变异的7.16%和6.92%;vubr5-1位于标记XD1-14和CP185之间,标记间的遗传距离为2.90 cM,在2种豆象处理中分别可以解释表型变异的6.96%和6.37%。【结论】构建了一个包含11个连锁群、182个多态性标记的豇豆遗传连锁图谱,检测到2个与抗豆象相关的QTL位点。

Quantitative Trait Locus Mapping of Bruchids Resistance Based on A Novel Genetic Linkage Map in Cowpea (Vigna unguiculata)

【Objective】Bruchids are the main storage pests of cowpea. The discovery of bruchids resistance genes is helpful for breeding resistant varieties and reducing the harm of bruchids to cowpea production.【Method】In this study, a RIL population of 282 lines derived from the cross between Zhongjiang No.1 (a bruchid-susceptible cultivar) and Pant-lobia-1 (a bruchid-resistant cultivar) was used for phenotype identification of bruchids resistance by artificial inoculation of Callosobruchus chinensis and Callosobruchus maculates. The two parents were used to screen polymorphic markers from 3 992 SSR markers of mung bean, adzuki bean and cowpea. Genotypes of 282 lines were analyzed using the polymorphic SSR markers. Based on the phenotype identification and genotype analysis, a genetic linkage map was constructed and the bruchids resistance gene(s) of cowpea was located using Inclusive Composite Interval Mapping (ICIM-ADD). 【Result】The results showed that Zhongjiang No. 1 and F₁ seeds were 100% susceptible to Callosobruchus chinensis and Callosobruchus maculates, and the damage rates of Pant-lobia-1 were 22.5% and 42.5%, respectively. It was speculated that the resistance of Pant-lobia-1 to bruchids was recessive inheritance. 182 polymorphic markers were obtained from 3 992 SSR markers of mung bean, adzuki bean and cowpea. Using those polymorphic SSR markers, a genetic linkage map with 11 linkage groups was constructed. The map covered a total length of 1 065.23 cM with an average interval of 5.85 cM between adjacent markers. Two bruchid-resistant QTLs from linkage groups 1 and 5 were discovered, which were temporarily named as vubr1-1 and vubr5-1. QTL vuvr1-1 was located between markers XD11-44 and HAAS_VR_2274, which genetic distance was 7.6 cM, explaining 7.16% and 6.92% of the phenotypic variation in the two bruchid-resistant tests respectively. QTL vubr5-1 was located between markers XD1-14 and CP185, which genetic distance was 2.9 cM, explaining 6.96% and 6.37% of the phenotypic variation in the two bruchid-resistant tests respectively. 【Conclusion】A genetic linkage map containing 11 linkage groups and 182 polymorphic markers was constructed. Two QTLs linked with bruchids resistance were identified on linkage groups 1 and 5.