空间诱变水稻DH104的稻瘟病抗性分析及抗病基因定位

摘要

The DH104, an indica rice mutant from Huhan B, and eight monogenic lines were subjected to resistance spectrum with 39 isolates collected from Guangdong Province, China. The results showed that DH104 conferred broader resistance spectrum than the eight monogenic lines. To identify and map the blast resistance gene in DH104, a representative isolate GD0193 was used to identify and map R gene from DH104. Isolate GD0193 was used for inoculating a population of F2 derived from the cross between DH104 and highly susceptible variety L101 (indica). The results showed that the segregation of resistant , and susceptible(S) progenies fitted a 3:1 ratio in the F2 population(313R: 97S, x 2 =0. 896 1), indicating the R gene was controlled by a single dominant gene, temporarily designed as Pixt(t) gene. The R gene was located between RM136 and RM7213 on chromosome 6 using SSR markers, with genetic distances 4. 9 and 1.5 cM respectively.%采用来自广东各稻作区的39个不同致病型稻瘟病代表菌株,对由沪旱B经空间突变而来的优质籼稻抗源DH104进行抗谱分析.结果发现,DH104的抗谱达到100%,而8个单基因品系的抗谱均在80%以下.为了挖掘和定位DH104含有的稻瘟病抗性基因,选用广致病谱病菌GD0193对DH104进行遗传分析.用GD0193接种DH104和高感稻瘟病籼稻材料L101杂交获得的F2群体,结果发现,F2群体抗病与感病植株的比例符合3:1的理论比值(313R:97S,x 2=0.8961),表明DH104对GD0193的抗性由一个显性主效基因控制,暂命名为Pixt(t)基因.利用SSR标记将其初步定位在第6染色体短臂RM136和RM7213之间,遗传距离分别为4.9和1.5 cM.