水稻二化螟越冬幼虫耐寒性物质的动态变化

为从生理生化水平上探讨二化螟越冬幼虫耐寒机制，分别对不同时期采集的二化螟越冬幼虫过冷却点及水、灰分、元素、脂肪、脂肪酸、甘油、总糖和蛋白质含量进行了测定.结果表明：越冬期幼虫过冷却点及游离水、游离脂肪、总糖和蛋白质含量变化均呈先减后增，而结合水、灰分、高含量元素（K、Na、Mg、Fe、Ni和Cr）、结合脂肪和甘油含量则呈相反变化；越冬期幼虫脂肪酸组分出现变化，但主要成分均为9-十六碳烯酸、9-十六烷酸和9-十八碳烯酸，其中前二者含量呈先减后增变化而后者则相反.越冬幼虫体内理化成分含量的动态变化可以反映其耐寒性强弱.

Dynamic changes of cold-resistant substances of overwintering Chilo suppressalis (Walker) larvae.

Aimed to understand the mechanisms of cold-resistance of overwintering Chilo suppressalis (Walker) larvae at physiological and biochemical levels, the supercooling point (SCP) and the contents of water, ash, elements, fat, fatty acid, glycrol, total sugar, and protein in the larvae samples collected at different time were determined. The results showed that the SCP and the contents of free water, dissociated fat, total sugar, and protein in the overwintering larvae decreased first and increased then, whereas the contents of bound water, ash, combined fat, K, Na, Mg, Fe, Ni and Cr, and glycerol decreased after an initial increase. The components of fatty acids in overwintering larvae had some changes, but the main components were still 9-hexadecenoic acid, 9-hexadecanoic acid, and 9-octadecenoic acid. The contents of 9-hexadecenoic acid and 9-hexadecanoic acid decreased first and increased then, while that of 9-octadecenoic acid was in adverse. The dynamic changes of the contents of test substances could reflect the cold-resistance of overwintering C. suppressalis larvae.