高温高湿对黄瓜黑星病菌孢子萌发及侵染的影响

THE EFFECT OF HIGH TEMPERATURE AND HIGH HUMIDITY REGULATION ON THE GERMINATION OF Cladosporium cucumerinumAND ITS INFECTION

采取温湿度相结合的方法来研究高温处理对黄瓜黑星病菌 (Cladosporium cucumerinum Ell.and Arth.)侵染的影响 ,比较研究了 35～ 5 0℃ 4个温度梯度、5 0 %～ 90 % 5个湿度梯度组合处理对病菌的致死作用。同一相对湿度下 ,随着温度的上升病菌的致死率增加 ,病菌致病力降低 ;在同一温度下随着湿度的不断升高 ,受处理的孢子萌发率和致病能力都逐渐下降。在 RH80 %以上、温度 4 0℃以上时 ,对孢子的致死率随着处理时间的延长而增高 ,此高温高湿处理病菌超过 2 h,病菌孢子不萌发 ,也基本没有接种发病率。通过高温控制苗期黄瓜黑星病的研究 ,初步确定高温高湿防治苗期黄瓜黑星病的最佳温度区间为 4 0℃ 2 h或 4 5℃ 1h(RH80 % )。

The effect of temperature and humidity on the infection caused by C. cucumerinum has studied. The combination of 4 temperature grades from 35℃ to 50℃ and 5 relative humidity grades ranging from 50% to 90% was tested to investigate the lethal threshold of the fungus.Under the same RH condition, the lethal ratio increased and pathogenicity decreased as temperature increase. On the other hand, at temperature between 35℃ and 50℃,with the increasing of the relative humidity, the germination rate of the treated spores and their pathogenicity decreased. When the temperature was above 40℃ and at the RH was over 80%, the lethality rate of the spores was promoted with lengthening the time of the treatment. Under this condition, for more than 2 h, the spores would never germinate, neither would the pathogenicity produce. The study on controlling the disease caused by C. cucumerinum in cucumber seedlings using high temperature indicated preliminarily that the optimum temperature and humidity ranges of controlling the pathogen in cucumber seedlings were 40℃ 2 h and 45℃ 1 h (RH 80%).