Analysis of Quantitative Trait Loci for Resistance to Brown Planthopper in Dongxiang Wild Rice (Oryza rufipogon Griff.)

The wild species in genus Oryza are important resources of genes resistant to brown planthopper (Nilaparvata lugens, BPH). The objective of this study was to identify quantitative trait loci (QTLs) in Dongxiang wild rice (O. rufipogon Griff.). A BC1F5 population and a BC3F3 population were developed for QTL mapping from the cross between Dongxiang wild rice and an indica rice cultivar, Xieqingzao B (O. sativa L. subsp. indica) as the recurrent parent. The BC1F5 population was infested with BPH collected from paddy fields. Two QTLs were identified, of which qBph2 was located in the interval of RM29-RG157 on chromosome 2 and qBph7 in the interval of RM11-RM234 on chromosome 7. The alleles from Dongxiang wild rice on qBph2 and qBph7, which explained 21.8% and 67.1% of the phenotypic variations, respectively, and reduced seedling mortality by 22.2% and 43.7%. These QTLs were validated using the BC3F3 population infested by BPH biotypes I, II, and III. This result shows that qBph2 confers resistance to biotypes I and II, and qBph7 confers resistance to biotypes I and III. Both QTLs show a great potential for improving BPH resistance in rice cultivars.

摘 要野生稻是水稻抗褐飞虱基因的重要种质资源。应用东乡野生稻与栽培稻协青早B构建的2套材料, 开展水稻抗褐飞虱基因鉴定研究。先以协青早B//协青早B/东乡野生稻BC1F5群体为材料, 应用褐飞虱田间种群进行抗虫鉴定, 检测到2个抗褐飞虱QTL, 其中, qBph2位于水稻第2染色体RM29–RG157区间, 东乡野生稻等位基因可降低死苗率22.2%; qBph7位于第7染色体RM11–RM234区间, 东乡野生稻等位基因可降低死苗率43.7%。进一步以协青早B为轮回亲本, 构建了BC3F3群体, 应用褐飞虱生物型I、II和III进行抗虫鉴定, QTL分析表明qBph2抗褐飞虱生物型I和II, qBph7抗褐飞虱生物型I和III。这2个QTL对培育抗褐飞虱水稻品种具有重要应用价值。