中文摘要：

将寄主和原产地不同的16株球孢白僵菌Beauveria bassiana的分生孢子分别悬浮于1 mL萌发液中,接受48℃恒温水浴45 min的热胁迫后,再在25℃下振荡培养24 h,以残存活孢率作为各菌株对热胁迫反应的耐热力指标.结果显示,供试菌株的残存活孢率在4.6%～87.1%之间变化,相互间差异极显著.热胁迫后有三株菌的残活孢率均在40%以上,耐热力强;四株菌的残存活孢率低于10%,耐热力弱;其余菌株的残存活孢率为11.0%～23.6%,耐热力居中.从上述菌株中挑选耐热力强、居中和弱的菌株各一株（残存活孢率分别为40.8%、15.8%和4.6%）,分别置于25℃、30℃及35℃下平板培养,其菌落生长表现明显与耐热力的强弱相关.虽然三菌株在25℃下的菌落生长无显著差异,但只有耐热力强的菌株能在35℃下正常生长并产孢,是罕见的球孢白僵菌耐热菌株.

英文摘要：

Aerial conidia of 16 Beauveria bassiana strains originally derived from different host insects worldwide were separately suspended in a nutritional solution containing 2% sucrose and 0.5% peptone. For each of the strains, the conidial suspension of 1 mL in a 10-mL glass tube was exposed to a thermal stress of water bath at 48℃ for 45 min and then incubated by shaking at 25℃ for 24 h. The residue viability of each strain after the thermal stress was assessed as an index of its thcrmotolcrancc. As a result, mean residue viabilitics in three assays, ranging from 4.6 to 87.1%, differed significantly among the 16 strains after exposure to the thermal stress. Of those, three strains were of high thcrmotolcrancc due to their residue viabilitics of 〉40% but four were weak in thcrmotolerancc due to their residue viabilitics of 〈10%. The residue viabilitics of the rest strains fell in a range of 11.0-23.6% and their thcrmotolerancc was thus intermediate. When three strains with the residue viabilitics of 40.8%, 15.8% and 4.6% after the thermal stress were grown separately on SDAY plates at 25, 30 and 35℃, their colony diameters were well in accordance with the level of the thcrmotolerancc. Only was the most thcrmotolcrant strain capable of growing and sporulating at 35℃, being unusual for B. bassiana, although colony diameters at 25℃ were not different among the three strains.