水稻纹枯病菌遗传差异的初步研究

水稻纹枯病菌的遗传分化给病害的防治特别是抗病育种工作带来了很大的困难.为了确定水稻纹枯病菌的致病力分化与其遗传差异的相关性,对25个分离菌的致病力、可溶性蛋白电泳及由RAPD得到的DNA指纹图谱进行了分析.研究结果表明,不同菌株间存在明显的致病力分化.基于菌体的可溶性蛋白电泳及其聚类分析表明菌株的致病力分化与蛋白质谱带的多样性具有一定的相关性,但未达到显著相关水平; RAPD分析结果表明菌株间相似系数最高的达99%,最低的却只有47%,反映出该病原菌存在许多不同的遗传位点,蕴藏着很强的遗传变异潜能;此外,菌株在DNA水平上的差异与其可溶性蛋白分析反映的遗传差异具有一定程度的一致性.由此可见,水稻纹枯病菌的致病力分化与其遗传差异具有一定的相关性,反映出该病原菌的致病力分化是有遗传背景的.

Preliminary studies on the genetic differentiation in rice sheath blight fungus

The genetic differentiation rice sheath blight fungus R. solani has made difficulties for control this disease, and particularly for resistance breeding. To identify the correlation between the variability in virulence and the hereditary differentiation of rice sheath blight fungus, 25 isolates were analyzed for virulence and electrophoretic profiles of soluble proteins, as well as the DNA fingerprinting by RAPD. The results showed that there existed high variability of virulence among the isolates. The electrophoretic profi les and cluster analyses based on protein patterns indicated that there was certain correlation between the virulence and protein polymorphism of all 25 isolates, but it was not statistically significant. The genetic diversity among the isolates showed by RAPD varied from 0.47 to 0.99, suggesting a high genetic variation potential among them. The results also showed that there were significant correlations between protein patterns and RAPD banding patterns of all isolates, which indicated that the variation in pathogenicity was linked to the hereditary differentiation of this fungal pathogen.