高温胁迫对内蒙古自治区和云南省致病疫霉生长及产孢的影响

Effects of High Temperature Treatment on Growth and Sporulation of Phytophthora infestans in Inner Mongolia and Yunnan

由致病疫霉[Phytophthora infestans(Mont.)de Bary]引起的马铃薯晚疫病是马铃薯生产上的重要病害,而温度是决定马铃薯晚疫病是否发生及发生程度的重要因素。为了明确不同温度及同一温度不同时间的胁迫处理对致病疫霉生长及产孢能力的影响,以18℃恒温培养作为对照,对采集自内蒙古自治区和云南两个地区的致病疫霉进行不同时间的高温胁迫处理。待菌株在18℃培养至三分之一皿时,每天在30,35和40℃分别进行3,6和9 h的变温处理,连续处理4 d,变温处理后的菌株继续18℃培养,直至对照菌株长满整个培养皿。结果表明,随着胁迫时间的延长和温度的升高,致病疫霉的生长受到不同程度的抑制。其中,内蒙古自治区菌株NY13-12受到的抑制最为明显,在30,35和40℃高温处理9 h时,菌落直径较对照分别减少28.74%、37.13%和53.89%。高温胁迫对致病疫霉的产孢具有不同的影响,30和35℃处理对致病疫霉的产孢量有刺激作用,但40℃处理对产孢有抑制作用。其中,菌株NY13-8在30℃处理9 h后,单位面积产孢量为1280个/mm^2,是对照的11.85倍,但40℃处理3 h后单位面积产孢量较对照减少37.04%。研究结果为晚疫病预测预报模型的构建及完善提供了数据支持。

Potato late blight caused by Phytophthora infestans(Mont.)de Bary is an important disease in potato production.Temperature is an important factor to determine the occurrence and degree of the potato late blight.In order to find out the effect of different temperature and time treatments on the growth and sporulation of P.infestans,the isolates collected from Yunnan and Inner Mongolia were treated with high temperatures for different times using culture at 18℃as a control.When the isolates were cultured to one-third of the petri dish at 18℃,isolates were treated at 30,35 and 40℃for 3,6 and 9 h respectively each day and the treatments were repeated for 4 d.After high temperature treatment,the isolates continued to be cultured at 18℃until the control covered the whole plate.The growth of P.infestans was inhibited to some extent with the increase of treatment time and temperature.The growth of NY13-12 which was collected from Inner Mongolia was inhibited most under different temperatures and times.After the isolate NY13-12 was treated at 30,35 and 40℃for 9 h,the colony diameter decreased by 28.74%,37.13%and 53.89%compared with the control,respectively.It was also found that the sporulation capacity of P.infestans was stimulated at 30 and 35℃,but inhibited at 40℃.After treated at 30℃for 9 h,the sporulation capacity per unit area of NY13-8 reached 1280 spores/mm^2,which was 11.85 times that of the control.However,the sporulation capacity per unit area of NY13-8 was 37.04%lower than that of the control at 40℃treated for 3 h.The results provide data supports for the construction and improvement of the prediction model of the late blight.