低温诱导培养对夜蛾斯氏线虫A54品系适低温特性的影响

用低温诱导培养的方法对夜蛾斯氏线虫Ａ５４的适低温特性进行了选育。结果表明，Ａ５４品系依序经过２５、２０、１５、１０℃４个温度梯度，每个温度连续培养３个侵染循环后，在１０℃下的侵染力有显著提高，对大蜡螟幼虫的致死速度加快，侵染周期缩短。与在２５℃下培养相比，侵入率提高了１０１９％，ＬＴ５０和侵染周期分别缩短了７４８ｈ和５ｄ。但返回在２５℃下培养２个侵染循环后，其适低温特性均有不同程度的丢失，侵入率比在１０℃培养下降低了２８３％，ＬＴ５０和侵染周期延长了３５ｈ和１４８ｄ。

Influence of the induced culture of Steinernema feltiae A54 strain in cold condition on its low temperature adaptability

The low temperature adaptability of Steinernema feltiae A54 strain induced culture in cold condition was studied. The results showed that the penetrative rate of A54 strain at 10 could be increased effectively, after continued culture for 3 infective cycles in order of temperature 25,20,15,10, respectively. The LT50 to Galleria mellonella and infective cycle time of A54 strain were also shorten at 10 , The penetrative rate cultured at 10 was increased by 10.19%, and infective cycle time and LT50 were shorten by 5 days and 74.8 hours, respectively, in comparison with that of 25 Nevertheless, the improved feature was lost partly in cultured for 3 cycles at 10 followed by 2 infective cycle at 25, and the penetrative rate reduced by 2.83%, LT50 and infective cycle prolonged by 35 hours and 14.8 days.