利用RAPD分子标记定位2个水稻稻瘟病菌非致病性基因

Identification of Two Avirulence Genes in the Rice Blast Fungus Magnaporthe grisea Using Random Amplified Polymorphic DNA (RAPD) Markers

选择日本鉴别品种新 2号和K5 9,对源于云南省的水稻稻瘟病菌可育性菌株CHL12 4(MAT1 1)和CHL12 5 (MAT1 2 )及其杂交后代 72个子囊菌株的非致病性 (无毒性 )进行了遗传分析。结果表明 ,菌株CHL12 4对新 2号 (含有效抗性基因Pish)和K5 9(Pit)的非致病性分别由非致病性基因Avr2 Pish和Avr2 Pit控制。通过对这 2个基因控制的非致病性反应进行列联卡方测验 ,显示这 2个基因连锁在一起 ,重组率为 2 6 .8%。进一步利用分离群体分析法 ,对这 2个基因进行了RAPD (随机扩增多态性DNA)分析。结果发现 ,2个RAPD标记OPW 0 6 64 5和OPW 1364 5与非致病性基因Avr2 Pish连锁 ,它们的重组率分别为 2 7.8%和 2 6 .5 %;另 1个RAPD标记OPR11517则与非致病性基因Avr2 Pit连锁 ,重组率为 2 3.5 %。

Avirulences of rice blast isolate CHL124 on rice cultivars Shin2 and K59 were studied with 72 asco-spore isolates generated from a cross between the isolate CHL124 and another fertile isolate CHL125. Segregation ratios of avirulences are suggestive of two avirulence genes Avr2-Pish and Avr2-Pit held in the isolate CHL124 which correspond to resistance genes Pish and Pit carried in cvs. Shin2 and K59, respectively. Moreover, the two avirulence genes were found to be linked each other with a recombination frequency of 26.8% through contingency χ 2 test. Furthermore, linkage analysis of the two avirulence genes with RAPD markers showed that two PAPD markers OPW06 645 and OPW13 645 were linked to the avirulence gene Avr2-Pish with recombination frequencies of 27.8% and 26.5%, respectively; and OPR11 517 was linked to another avirulence gene Avr2-Pit with recombination frequency of 23.5%.