Identification of pathogen causing gummy stem blight of Cucumis melo and Trichosanthes kirilowii in Anhui Province and screening of effective fungicides
To identify the pathogen causing gummy stem blight of Cucumis melo and Trichosanthes kirilowii,and screen effective fungicides for the management of this disease,symptomatic samples were collected from the fields lo-cated in Shucheng County and Chaohu City,Anhui Province in 2021 and 2022.Pure cultures were obtained consist-ently using tissue separation method,and five representative isolates were selected for morphological observation and molecular identification.Partial fragments of internal transcribed spacer(ITS)and large subunit(LSU)regions,be-ta-tublin 2(TUB2)genes of the isolates were amplified and sequenced.Pathogenicity assays were carried out to con-firm Koch's postulates.The pathogen was finally identified as Stagonosporopsis citrulli based on morphological charac-teristics and multi-loci sequence analysis.The indoor toxicity test results indicated that boscalid and prochloraz ex-hibited relatively higher inhibitory effects among seven fungicides,with both EC50 ranging from 0.010 6 to 0.043 8 μg·mL-1.The two fungicides could be preferentially utilized in rotation to control the disease caused by S.citrulli.