刺萼龙葵病原菌的分离鉴定及致病力的研究

[Objective]Solanum rostratum is a malignant invasive weed in China,in order to determine the pathogen of the weed and to develop biological control measures for its reasonable and effective containment.[Method]In this study,leaf samples of S.rostratum with typical diseases were collected by investigating the disease of eight sites in Liaoning and Jilin province,China.The pathogens were isolated using the tissue isolation method and identified based on their morphological characteristics and molecular biology techniques.The pathogenicity was tested through artificial inoculation of spore suspensions from the pathogen onto seeds,isolated leaves,and plants of S.rostratum.[Result]A total of 120 diseased leaves were collected in the survey.According to the morphological and molecular characteristics,five pathogens were identified as Alternaria alternata,Epicoccum sorghinum,Fusarium equiseti,Curvularia hawaiiensis,and Nigrospora oryzae,respectively.All five pathogens exhibited pathogenicity,among which E.sorghinum and N.oryzae showed strong pathogenic effects.The inhibition rate of seed root germination length by N.oryzae was 47.76%,and the disease indexes of isolated leaves and plants inoculated with this pathogen were 60%and 70%,respectively,which was medium pathogenic.The inhibition rate of seed root germination length by E.sorghinum was 36.64%,and the disease index of plants inoculated with this pathogen was 78.3%,which showed strong pathogenicity.[Conclusion]This is the first investigation of the disease occurrence and pathogens of S.rostratum in China.The results demonstrated that there are five pathogens causing disease of this weed in Liaoning and Jilin province.E.sorghinum and N.oryzae were the dominant pathogenic species,and different pathogens have significant differences in the pathogenicity of S.rostratum.