铁皮石斛炭疽病病原菌的分离鉴定及其有效杀菌剂的筛选

铁皮石斛炭疽病是近年来发生在浙江铁皮石斛种植区的一种严重病害,主要危害石斛的叶片,形成圆形或近圆形并有凹陷的黄褐色或黑色叶斑,严重时叶片枯死,影响铁皮石斛的产量和质量。通过对铁皮石斛炭疽病典型症状样本的采集、病原菌的分离、纯化、致病性测定、形态观察、rDNA-ITS序列分析,明确病原菌为胶孢炭疽菌Colletotrichum gloeosporioides。选择11种杀菌剂采用生长速率法对病原菌进行了药剂敏感性测定,结果表明,6%春雷霉素可湿性粉剂1 000倍液、70%甲基硫菌灵可湿性粉剂1 000倍液对病菌抑菌效果接近100%。

Isolation and identification of the pathogen of Dendrobium officinale anthracnose and fungicide screening in laboratory

In recent years, anthracnose of Dendrobium officinale has become a serious disease in D. officinale producing areas of Zhejiang Province. It mainly infects the leaves and forms round or nearly round, dark brown or black sunken spots. In serious cases, it causes the leaves to wither. In this study, samples with typical disease symptoms were collected and then the pathogen was isolated and purified. Based on pathogenicity test, morphology observation and 16S rDNA-ITS sequence analysis, the pathogen was identified to be Colletotrichum gloeosporioides. Moreover, the indoor inhibition activities of 11 kinds of fungicides were investigated by mycelial growth rate method. The results showed kasugamycin 6% WP 1 000 times and thiophanate-methyl 70% WP 1 000 times had strong inhibition action to the pathogen, with the inhibitory ratio close to 100%.