龙胆草斑枯病病原生物学研究

The Etiology of Rough Gentian Leaf Blight

对龙胆草(GentinascabraBunge)斑枯病病原生物学特性的研究结果表明 ,龙胆草斑枯病病原菌为龙胆壳针孢(SeptoriagentianaeThume)。该病原菌是一种耐高湿、高温、喜光性真菌 ,生长的最适温度是20～25℃ ,最适pH值6～7。分生孢子的形成需要光照、营养和适宜的温湿度条件 ,分生孢子萌发一般需要较长时间 ,在25℃蒸馏水条件下 ,12h开始萌发 ,48h的萌发率为50% ,72h的萌发率为90 %左右。加入糖分和寄主汁液可加速孢子的萌发。分生孢子的致死温度为50℃。该病菌主要以分生孢子、分生孢子器和菌丝在田间病残体上越冬 。

Rough gentian is an important medical cultivated plant and has higher medical and economic value. Rough gentian leaf blight is caused by Septoria gentianae. This paper reports the etiology of Rough gentian leaf blight. The optimum temperature of germination for the conidia and growth for the hypha of Septoria gentianae was 20～25℃. The optimum pH Value was 6～7. In water, it started to germinate at least in 12 hours. The germination rate reached up to about 50% in 48 hours and 90% in 72 hours at 25℃. The lethal temperature for conidia was 50℃ (10 minutes). Under the natural conditions, the conidia could keep vital at least 8 months.