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2009年长春农博园瓜类白粉病大发生,而且大量闭囊产生在葫芦科的四个属(葫芦属、黄瓜属、栝楼属、南瓜属)植物上。对病害发生的严重度和病情指数进行了调查,结果表明园中栽培的所有品种均为感病品种。形态学观察显示分子孢子串生,具纤维体,闭囊壳只含有一个子囊,内含8个子囊孢子,子囊顶端孔较宽(15.6-28.8μm)。有性和无性形态学特征表明该菌应属于Podosphaera xanthii。基于rDNAITS序列的分子系统学分析表明该菌与GenBank中已报道的该种在其他地区瓜类上的序列以及在其他寄主上的序列聚在一个分枝。第一次报道了在栝楼属上发现白粉菌的闭囊壳,第一次在吉林省发现西葫芦上产生闭囊壳。此外西瓜上的白粉菌虽然未产生闭囊壳,但为吉林省新记录。有关瓜类白粉菌的寄主范围、流行学、抗病品种筛选和防治有待进一步研究。
2009 Changchun Agricultural Garden Melon powdery mildew occurred, and a large number of closed capsule produced in the Cucurbita four genera (Cucurbita, Cucumber, Trichosanthes, Cucurbita) plants. The severity of the disease and disease index were investigated, the results show that all cultivars in the garden are susceptible varieties. Morphological observation showed that the spores were sporogenesis and had fibrous body. The closed shell contained only one ascus and contained 8 ascospores. The apical pore of the ascus was wide (15.6-28.8μm). Sexual and vegetative morphological features indicate that the strain should belong to Podosphaera xanthii. Molecular phylogenetic analysis based on the rDNAITS sequence indicated that this bacterium clustered with one of the previously reported GenBank sequences in other regions and sequences on other hosts. For the first time, it was reported that the closed shell of powdery mildew was found in the genus Trichosanthes, and the first closed shell was found on the summer squash in Jilin Province. In addition watermelon on the powdery mildew although not produce closed shell, but for the new record in Jilin Province. Concerning melon host range, epidemiology, disease resistance screening and control needs further study.