闽楠叶斑病病原鉴定及其生物学特性测定

闽楠是我国特有珍稀优良用材乡土树种,市场前景广阔。叶斑病是闽楠推广种植过程中新出现的叶部病害,可影响树木正常生长。闽楠叶斑病病原鉴定及生物学特性等研究,有助于明确病原分类地位和病害发生流行规律,从而科学有效地指导防治。通过形态学特征观测和r DNA-ITS序列分析,确定闽楠叶斑病病原为小孢拟盘多毛孢(Pestalotiopsis microspora)。生物学特性测定结果表明:闽楠小孢拟盘多毛孢ZZ-03菌株以Czapek或PDA+PBL培养基(pH 6.0)28℃黑暗恒温培养有利于菌丝生长;以PDA培养基(pH 8.0)28℃黑暗恒温培养有利于菌株产孢;以pH 8.0、28℃、全黑暗有利于分生孢子萌发;以葡萄糖为C源、牛肉浸膏为N源有利于菌丝生长,以葡萄糖为C源、蛋白胨为N源有利于产孢;分生孢子萌发与相对湿度呈正相关。

Pathogen identification of Phoebe bournei leaf spot and determination of its biological characteristics

Phoebe bournei, one of the national second-class endangered plants, is the excellent precious timer species with broad market prospect. Leaf spot was newly found leaf disease, which resulted in stress and abnormal growth of plants in the extension of Ph. bournei plantation. The causing agent of the disease was identified as Pestalotiopsis microspora by morphological characteristics and rDNA-ITS sequences analysis. The result of the biological test showed that the optimal conditions for mycelia growth of Pe. microspora strain ZZ-03 were Czapek agar or PDA+PBL(pH 6.0)at 28℃ in dark. The spore production was optimal on PDA medium(pH 8.0)at 28℃ in dark. Conidia germination was positively correlated with relative humidity at 28℃ with pH 8.0 in dark. The best carbon and nitrogen sources for mycelia growth were glucose and beef extract, respectively, while glucose and peptone were the best for conidiation, respectively.