籼稻品种‘IR13427-45-2-1-2-2-2’抗白背飞虱QTL定位

Mapping of the quantitative trait locus conferring white-backed planthopper resistance in indica cultivar 'IR13427-45-2-1-2-2-2'

[目的]白背飞虱及其传播的南方黑条矮缩病危害日益加剧,严重危及水稻生产。本研究旨在发掘水稻抗白背飞虱基因,为抗白背飞虱品种培育提供有用的基因资源。[方法]利用高抗白背飞虱水稻品种‘IR13427-45-2-1-2-2-2’(简称‘IR13427’)与感虫品种‘宁粳3号’构建1个包含92个家系的F2:3群体,进行白背飞虱抗性鉴定,选取极端个体进行连锁分析,构建有连锁迹象的染色体连锁图谱,运用MAPMAKER/EXP Version 3.0软件进行QTL(quantitative trait locus)检测。[结果]利用10个极感和12个极抗个体,在第5、6和9染色体上发现连锁迹象,构建了这3条染色体的连锁图谱,进行QTL检测,结果在第5和第6染色体检测到2个QTL,分别命名为q WBPH5和q WBPH6,贡献率分别为11.90%和18.30%,LOD值为2.42和3.28。[结论]籼稻品种‘IR13427’对白背飞虱的抗性由数量性状位点控制,本研究检测到2个抗白背飞虱QTL,为水稻抗白背飞虱基因的克隆及品种培育奠定基础。

[ Objectives] The increasing damage caused by the white-backed plant hopper（WBPH） and its transmitting southern rice black-streaked dwarf virus （SRBSDV） seriously threatens the rice （ Oryza sativa L. ） production. The aim of present study is to identify WBPH-resistance genes for developing resistance cuhivars. [ Methods] We constructed an F2,3 population containing 92 lines derived from a cross between highly resistant indica variety, ＇ IR13427-45-2-1-2-2-2＇ , and susceptible japonica variety, ＇ Ningjing 3＇ , and then evaluated it for WBPH resistance. The candidate chromosomes harboring WBPH resistance QTL （quantitative trait locus）were screened by extreme resistant and susceptible lines, then the molecular linkage map was constructed to conduct QTL analysis with MAPMAKER/EXP Version 3.0. [ Results] Chromosome 5,6 and 9 were identified as candidate chromosomes with WBPH resistance QTL using 10 high susceptible and 12 resistant lines,respectively. Then the molecular linkage maps of these three chromosomes were constructed. Two QTL,qWBPH5 and qWBPH6,conferring WBPH resistance were detected, qWBPH5 was located on chromosome 5 with a LOD score of 2.42,explaining 11.90% of the phenotypic variance, qWBPH6 was mapped on chromosome 6 with a LOD score of 3.28, explaining 18.30% of the phenotypic variance. [ Conclusions ] The WBPH resistance of the indica variety,＇ IR13427-45-2-1- 2-2-2＇ , may be contributed by quantitative trait loci. The newly identified two QTL conferring WBPH resistance in this study provides the foundation for cloning of rice WBPI-I-resistance genes and developing resistant cultivars to reduce the damage caused by WBPH and SRBSDV.