水稻全生育期稻瘟病抗性遗传及其基因定位研究

Genetic Analysis of Rice Blast Resistance and Identification of Resistance Genes Throughout all Stages in Rice

稻瘟病是最严重的世界性水稻病害之一。本实验利用高抗稻瘟病品种194-3和珍汕97B构建的重组自交系群体,通过自然诱发实验,在两个年度重复的情况下,全生育期调查水稻生长的3个关键时期-分蘖期叶瘟、抽穗期叶瘟和成熟期穗颈瘟的抗性表现,通过集团分离分析法(bulked segregation analysis,BSA)初步定位稻瘟病主效抗性基因。结果表明分蘖期和抽穗期的叶瘟、以及穗颈瘟的抗性表型频率均呈双峰分布,说明控制水稻叶瘟和穗颈瘟均表现为一对主效基因控制;全基因组分子标记分析将该稻瘟病抗性基因定位于水稻第6染色体上,处于分子标记AP22和RM19766之间。该抗性基因来源于重组自交系的抗性亲本194-3,并命名为R6。本实验为稻瘟病的持久抗性分子标记辅助选择育种和基因克隆提供了基因资源。

Rice blast is one of the most prevailing diseases worldwide. A population of recombinant inbred lines, which was derived from a cross between a resistant cultivar 194-3 and a susceptible cultivar Zhenshan 97B, was identified for its blast resistance under natural environmental inoculation and mapped the resistance gene by bulked segregate analysis （BSA）. One gene, R6, was located in the region between two markers AP22 and RM19766 on chromosome 6. The major resistance gene was from the resistant cultivar 194-3. This gene was showing to resist leaf blast and neck blast during the whole duration at the natural environment. Our results will be useful for the durable resistant breeding program by marker-assisted selection and gene cloning of the R6.