辽宁西瓜衰萎病的病原菌鉴定

Identification of causal agent of watermelon collapse disease in Liaoning

近年来，辽宁省新民市西瓜上发生一种新病害，病株根系衰弱、根毛数量减少，根部表皮粗糙，韧皮部木栓化，成软木塞状。随病情发展，植株叶片自茎基部向顶部逐渐褪绿、变黄、枯萎，重病植株逐渐衰败、凋萎、死亡，故称之西瓜衰萎病。国际上，许多国家有关于西瓜、甜瓜的衰萎病发生的报道，而我国未见相关研究报道。

A watermelon collapse was a new disease occurred in watermelon production area of Xinmin, Liao- ning Province. The diseased root samples with typical symptom were collected from the fields. The fungal isolates were obtained and cultured on media for morphological identification, conduct of Koch＇s postulates and sequencing rDNA ITS. The results showed that the pathogen was morphologically identified as Acremoni- um cucurbitacearum Alfaro-Garcfa, W. Gains ＆ J. Garcfa-Jim6nez, and the ITS sequence analysis confirmed 100% similarity with those of A. cucurbitacearum downloaded from GenBank. The artificial inoculation of the fungal isolates produced the similar symptoms as that in the field. The field investigation indicated that the di- sease occurred widely in watermelon production area of Xinmin, Liaoning province.