Pathogen identification and indoor fungicide screening of southern blight of Polygonatum cyrtonema
In order to clarify the species and biological characteristics of the pathogen of southern blight of Polygona-tum cyrtonema and screen suitable fungicides,the diseased plants of Polygonatum cyrtonema were collected from Nanchuan District of Chongqing City,and the pathogen strain BJB of Polygonatum cyrtonema was isolated and purified by sclerotia separation method.The pathogenicity was verified according to Koch's rule.The species of pathogenic bacteria were identi-fied by morphology and molecular biology.The suitable growth conditions of pathogenic bacteria were determined by biologi-cal test,and the suitable fungicides were screened by indoor efficacy test.The results showed that the strain BJB isolated and purified in this study was Athelia rolfsii.The suitable growth conditions of the pathogen were as follows:potato sucrose agar(PSA)medium,temperature 25℃,pH 4,sucrose as carbon source,sodium nitrate as nitrogen source,and dark culture.The lethal temperature of mycelium and sclerotium of the pathogen was 45℃and 55℃,respectively.The fungicide tebuconazole showed the best inhibitory effect a-gainst the pathogen,and the median effective concentra-tion(EC50)was 0.420 μg/mL.The EC50 values for fludi-oxonil,triadimefon and azoxystrobin were 1.750 μg/mL,1.991 μg/mL and 2.940 μg/mL,respectively.The results of this study provide a basis for the diagnosis and preven-tion of southern blight disease of Polygonatum cyrtonema.
万方数据
维普
