籼稻资源WD15515中抗褐飞虱QTL的定位研究

褐飞虱是我国水稻生产上最严重的虫害之一, 培育和种植抗褐飞虱水稻品种是控制褐飞虱的有效途径。WD15515是一份高抗褐飞虱的籼稻种质资源。利用9311与WD15515杂交培育了F₂群体, 对F₂植株进行SSR分子标记分析, 测定植株上褐飞虱的蜜露分泌量、虫体增重量和增重比, 作为抗虫性指标。通过QTL IciMapping3.0进行作图分析, 在第2、第4、第9染色体上共检测到4个抗褐飞虱QTL。其中第2染色体上检测到2个QTL, 以蜜露分泌量检测到的qBph2-1位于SSR标记RM71~RM6911之间, LOD值为3.68, 表型贡献率为11.08%；以虫体增重量和增重比检测到的qBph2-2位于标记RM6911~RM521之间, LOD值分别为3.31、4.05, 表型贡献率分别为7.81%、9.38%。以蜜露分泌量、虫体增重量和增重比为指标在第4染色体上检测到qBph4, 定位于标记RM16996~RM17075之间, LOD值分别为11.11、13.81、15.41, 表型贡献率达到44.38%、45.24%、52.40%。同样, 以蜜露分泌量、虫体增重量和增重比在第9染色体上检测到qBph9, 定位于标记RM219~RM6444之间, LOD值分别为2.59、4.04、3.63, 表型贡献率分别为10.91%、12.39%、10.01%。上述结果表明, qBph4是一个抗褐飞虱主效基因。本项研究结果为抗褐飞虱水稻育种提供了新的基因资源。

Analysis of QTLs for Brown Planthopper Resistance in Indica Rice WD15515

Brownplanthopper (BPH) is one of the most destructive insect pests of rice. WD15515 is an indica germplasm highly resistant to BPH. An F₂ population was developed from the cross between 9311 and WD15515. One hundred F₂ plants were genotyped by using SSR markers and evaluated for BPH-resistance by measuring the honeydew weightsecreted by BPH(HW), the body weight increment (WB) and the body weight increment ratio (WRB). A total of four QTLs for BPH resistance were identified. The qBph2-1, based on HW(honeydew weight), was detected between RM71 and RM6911 on chromosome2, with LOD score of 3.68 and explaining the 11.08% of phenotypic variation. The qBph2-2, based on both WB and WRB, was mapped between RM6911 and RM521 on chromosome 2, with LOD score of 3.31 and 4.05 and explaining 7.81% and 9.38% of the phenotypic variation, respectively. The qBph4, based on HW, WB and WRB, was detected between RM16996 and RM17075 on chromosome 4, with LOD score of 11.11, 13.81, and 15.41 and explaining 44.38%, 45.24%, and 52.40% of the phenotypic variation, respectively. The qBph9, based on HW, WB, and WRB, was detected onchromosome 9 between RM219 and RM6444, with LOD score of 2.59,4.04, and 3.63. This locus explained 10.91%,12.39%, and 10.01% of the phenotypic variation in this population, respectively. qBph4 is amajorgene for BPH-resistance. This result providesthenew resources for BPH-resistance breeding.