利用分子标记和接种鉴定分析美国水稻育种亲本的稻瘟病抗性

稻瘟病是由真菌Magnaporthe oryzae引起的,水稻与稻瘟病菌的互作符合经典的“基因对基因”学说,抗稻瘟病基因Pi-ta可有效防治携带A VR-Pita1稻瘟菌的侵染.本研究利用位于Pi-ta基因前端的显性 .分子标记YLI53/YL153和位于中间区域的显性分子标记YL155/YL87对39份来自美国的水稻...

Analysis of Rice Blast Resistance in Rice Breeding Parents from USA Using Molecular Markers and Pathogenicity Assays

Rice blast disease is caused by the fungal pathogen Magnaporthe oryzae.The Pi-ta gene in rice is effective in preventing infections by strains of M.oryzae that carry AVR-Pita1 in a gene for gene specificity.In the present study,two dominant markers YL153/YL154 and YL155/YL87 derived from different regions of the Pi-ta gene were used to examine the existence of Pi-ta in 39 breeding parents.A mixture of avirulent races IC-17,IB-49,IB-1,IE-1,IG-1,IH-1 of M.oryzae was also used to inoculate each rice genotype.The results indicated that there were 26 breeding parents possessed the Pi-ta gene examined by molecular markers YL153/YL154 and YL155/YL87.Among the 26 breeding parents,21 of which were resistant,and 5 were susceptible to mixed races of M.oryzae.Eleven breeding parents were determined to lack Pi-ta by molecular markers,7 of which were resistant,4 of which were susceptible.Inconsistencies of the existence Pi-ta were observed in two breeding parents by molecular markers YL153/YL154 and YL155/YL87.That is,one marker indicates the presence of Pi-ta and other marker indicates the absence of the Pi-ta gene,while their blast reaction was susceptible.These apparent recombinants may be useful for further studies on gene function.These findings demonstrated the importance of using molecular markers in conjunction with pathogenicity assays for selecting breeding parents in rice breeding.