太子参叶斑病病原菌鉴定及防治药剂筛选

采用形态学结合分子系统学方法对引起贵州黄平县和六枝道地中药材种植基地太子参叶斑病的病原菌进行鉴定,并以菌丝生长法对75%百菌清可湿性粉剂、70%甲基硫菌灵可湿性粉剂、37%苯醚甲环唑可湿性粉剂、40%氟硅唑乳油以及1%申嗪霉素悬浮剂进行了室内药效筛选。结果表明:引起贵州太子参叶斑病的病原菌为Ascochyta versabilis,该病原菌为太子参病害新记录;5种杀菌剂除75%百菌清可湿性粉剂2 000倍对A.versabilis的抑菌率较低外(51.4%),其余4种供试杀菌剂均具有较强的抑菌作用。70%甲基硫菌灵可湿性粉剂2 000倍、37%苯醚甲环唑可湿性粉剂2 000倍和40%氟硅唑乳油2 000倍对A.versabilis的生长具有较强的抑制作用,其抑制率均高于90%;1%申嗪霉素悬浮剂2 000倍对该病原菌的抑制率为72.3%。

Pathogen identification of leaf spot on Pseudostellaria heterophylla and screening of fungicides for its control

Based on morphological characteristics and ITS phylogeny analysis, the pathogen caused leaf spot on Pseudostellaria heterophylla was isolated and identified from Liuzhi and Huangping, Guizhou Province. The inhibition effects of chlorothalonil 75% WP, thiophanate-methyl 70% WP, difenoconazole 37% WP, flusilazole 40% EC, phenazino-1-carboxylic acid 1% SC on the pathogen of leaf spot were tested by mycelial growth method in laboratory. The results indicated that the pathogen was identified to be Ascochyta versabilis. Among the five fungicides, chlorothalonil 75% WP (2 000×) showed lower inhibition rates (51.4%) against A.versabilis, while the other four fungicides had good control efficacies, with the inhibition rates of more than 90% for difenoconazole 37% WP (2 000×), thiophanate-methyl 70% WP (2 000×) and flusilazole 40% EC (2 000×), and 72.3% for phenazino-1-carboxylic acid 1% SC (2 000×), respectively.