摘要： 为了检测及提高球孢白僵菌HFW-0对高温环境的耐受力,将浓度为108孢子/mL的孢悬液,在48℃下恒温振荡水浴,不同时间取出测定孢子存活率,同时将处理液接种制备孢子粉,测定下一代的产孢量、疏水性、不同温度下的萌发中时、生长速率、毒力以及胞外蛋白酶和几丁质酶的活性.结果表明,高温胁迫处理能够在一定程度上提高HFW-0菌株的耐热力.其中处理120 min孢子存活率可达到80%以上,处理110 min在27℃下产孢量是对照的3倍多,两者的疏水性均显著高于对照.各处理一代菌株分生孢子在32℃下萌发中时(GT0)均显著低于对照,在32,34℃下胞外蛋白酶和几丁质酶活性高于对照,但各处理间差异不显著.以二龄初小菜蛾为供试幼虫,在27℃下,各处理的毒力仍均低于未处理对照,但在32℃下均显著高于对照,在34℃下对照及处理分生孢子均无杀虫活性.

关键词: 高温胁迫, 球孢白僵菌, 耐热力

Abstract: In order to test and improve the tolerance of Beauveria bassiana HFW-05 to high temperature environment,aerial conidia of Beauveria bassiana HFW-05 was separately suspended in a solution containing 0. 05% OP with concentration of 108 conidia /mL. And the conidial suspension of 1 ml in a 1. 5 mL tubes were exposed to a thermal stress of water bath under 48℃ for different times. Then mensurated the residue viabilities of conidia,rate of growth, sporulation,hydrophobicity virulence,extracellular protease and chitinase. The result showed that high temperature stress could enhance the thermotolerance. The residue viabilities of conidia could reach 80% or more which treated for 120 min and the sporulation which treated for 110 min was as 3 times as control under 27℃ . Hydrophobicity of the both was significantly higher than control under 32℃ ,the half germination time(GT50 ) were significantly lower than control,the extracellular protease and chitinase were also significantly higher than control under 32℃ and 34℃ . The control had higher mortality rates than others under 27℃ ,and had lowest mortality rates under 32℃ . The control and other treatments have no insecticidal activity under 34℃ .

Key words: Conidial response to thermal stress, Beauveria bassiana, Thermotolerance

中图分类号: 

• S476+.12