11株草茎点霉培养特征、致病力及RAPD分析

Analysis of the Cultural Characteristics,Pathogenicity and RAPD of 11 Phoma herbarum Isolations

从辽宁的沈阳、抚顺、鞍山等地采集的鸭跖草叶斑病病叶上共分离得到11个菌株。这些菌株在培养形态、生长速率、产孢能力、致病能力和产毒能力方面差异显著。其中SY1菌株的生长速率最快,SY4菌株的产孢能力最强。SYAU-06菌株的致病力最强,接种在鸭跖草叶片上发病率达到97.33%,病情指数为87.23,显著高于其他菌株。在液体培养基中SYAU-06菌株的产毒量最多,毒素的致病性也最强,在鸭跖草叶片上可形成面积为13.63 mm2的病斑。11个菌株基因组DNA经RAPD分析表明,不同菌株间扩增图谱差别明显,表现出各菌株间明显的遗传多态性。经聚类分析显示草茎点霉不同菌株的RAPD类群与致病力有一定的相关性。

Eleven isolations of Phoma herbarum were obtained from diseased leaves collected from Shenyang,Fushun,Anshan and other regions in Liaoning province.There were significant differences in cultural characteristics,growth speed,sporulation capacity,pathogenicity and toxin-producing capability among different isolations.In all isolations SY1 grew most rapidly and SY4 produced most spores. SYAU-06 strain had most virulence of which diseased leaf rate was 97.33% and disease index was 87.23 after being inoculated into dayflower.The pathogenicity of SYAU-06 strain was significantly greater than that of others.Furthermore,the toxin yield produced by the strain in liquid medium was the most and its pathogenicity was the highest forming 13.63 mm2 lesion in leaf.There were obvious difference in RAPD amplification patterns among 11 isolations demonstrating their genetic polymorphism.There was relationship between RAPD group of Phoma herbarum and their pathogenicity.