稻瘟菌对水稻品种梅雨明的无毒性的遗传分析和分子标记

IDENTIFICATION OF A RAPD MARKER LINKED WITH THE LOCUS IN RICE BLAST FUNGUS CONFERING AVIRULENCE TO RICE CULTIVAR TSUYUAKE

将交配型为 a、并对水稻品种梅雨明不致病的稻瘟菌菌株 S152 2与对该品种致病的、交配型为A的稻瘟菌菌株 P131和 S159杂交 ,分别获得了 2 4和 56个单子囊孢子后代。致病性测定结果表明 :这些后代菌株在梅雨明上的致病个体与不致病个体的比例近等于 1∶ 1。由此推测 :稻瘟菌对水稻品种梅雨明的无毒性是由 1个基因控制的。进一步通过 RAPD比较了致病后代与不致病后代的 DNA多态型 ,获得了 1个与该无毒基因连锁的、长度为 10 0 0 bp的 RAPD标记 ,两者间的遗传距离为3.7c M。

Twenty four and fifty six mono ascospore progenies were obtained from two crosses of the strains of rice blast fungus, S1522 with P131 and S159. The strain S1522 belonging to mating type a is avirulent, and P131 and S159 belonging to mating type A are virulent to rice cultivar Tsuyuake. Pathogenicity test showed that ratio of avirulent progenies to virulent ones was approximately 1∶1, indicating that a single locus confers the avirulence in S1522 to Tsuyuake. RAPD technique was used to compare difference in DNA polymorphism between the avirulent and virulent progenies. One RAPD marker with about 1 000 bp was found closely linked with the avirulence locus, and genetic distance between the marker and the avirulence locus is about 3.7 cM.