新番茄粉孢菌Oidium neolycopersici生物学特性的研究

摘要

Biological characteristics of Oidium neolycopersici, the main agent causing tomato powdery mildew, were investigated. The test revealed that the conidia germinated at the optimal temperature of 20-25 ℃ and the optimal relative humidity of 80%-100%, but failed to germinate in water drop. It was also found that the conidial germination had no strict requirement for illumination and pH value. They could germinate at pH3 -12 with above 90% germination percentage. The fungus could utilize various carbon sources, and mannitol and galactose are the best of all. Among nitrogen sources, NO3-N (nitrate) is the best, but NH4-N and organic nitrogen could inhibit the conidial germination. The lethal temperature for conidial germination was 44 ℃ for 10min.%新番茄粉孢菌Oidium neolycopersici是近几年引起番茄白粉病的主要病原菌.在国内首次对该菌的生物学特性进行了研究.结果表明:新番茄粉孢菌分生孢子萌发的适宜温度范围为20-25℃,最适相对湿度范围为80％-100％,在水滴中不能萌发；该菌对光照条件和酸碱度的要求不严格,在pH3- 12时其萌发率均能达到90％以上；在碳氮源利用方面,该菌分生孢子对各种碳源均能利用,以甘露糖和半乳糖效果最好；氮源以硝态氮(硝酸钾)为佳,铵态氮、有机态氮对其萌发有抑制作用；分生孢子萌发的致死温度为44℃ 10min.