低温处理对亚洲玉米螟幼虫抗寒性的诱导效应

Effect of low temperature treatment on larvae of the Asian corn borer,Ostrinia furnacalis(Guenée) (Lepidoptera:Pyralidae)

室内条件下将亚洲玉米螟Ostriniafurnacalis(Guen啨e)幼虫放置在5℃(LT1处理组)和0℃(LT2处理组)下低温处理2h后,分别测定了其低温诱导识别温度、存活率、抗寒性、过冷却点、体内水分和脂质含量百分率,并进行抗冻特异蛋白的诱导;利用SDS-PAGE方法分析了低温诱导后亚洲玉米螟5龄幼虫血清中抗冻特异蛋白。结果表明:亚洲玉米螟3、4和5龄幼虫的低温诱导识别温度分别为-13·5℃、-16·5℃和-18·5℃;3、4和5龄幼虫存活率LT2组>LT1组>对照组(P<0·05);随虫龄增加,幼虫抗寒性逐步增强;对幼虫过冷却点无明显影响(P>0·05);幼虫水分和脂质含量百分率为LT2组>LT1组>对照组,且随虫龄增加,虫体含水率和脂质含量百分率增高(P<0·05);低温诱导产生了一种分子量约为29·0kD的抗冻特异蛋白。研究结果表明低温诱导可以增强亚洲玉米螟幼虫的抗寒性。

The larvae of the Asian corn borer, Ostriniafurnacalis （Guen6e）, were treated for 2 h in the laboratory under the temperature 5℃ （LT1） and 0 ℃ （LT2）, respectively. The discriminating temperature, survival rate, cold tolerance, super-cooling point, and the rates of water and lipid in the Asian corn borer larvae after low temperature treatment were determined, respectively. The special antifreeze protein in the serum of the 5th instar larvae of O. furnacalis after low temperature treatment was analyzed with SDS-PAGE. The results showed that the discriminating temperatures for the 3rd, 4th and 5th instar larvae were - 13.5℃, - 16.5℃ and - 18.5℃, respectively. The survival rates of 3rd, 4th and 5th instar larvae all showed the tendency of LT2 〉 LT1 〉 the control group after low temperature treatment （ P 〈 0.05 ）. With the increase of instar, the cold tolerance of the larvae increased gradually, and the rates of water and lipid in the larvae also increased significantly （ P 〈 0.05 ）. The super-cooling point of the larvae was not effected significantly by low temperature （P 〉 0.05）. The rates of water and lipid in larval body showed the tendency of LT2 〉 LT1 〉 the control group after low temperature treatment. A special antifreeze protein with the molecular weight about 29.0 kD was detected in the 5th instar larvae. It was so concluded that low temperature treatment could increase the cold tolerance in the Asian corn borer larvae.