华北地区越冬代棉铃虫抗寒性研究

发布时间：2018-03-07 16:42

本文选题：棉铃虫　切入点：Bt棉花　出处：《湖南农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：棉铃虫是世界上重要的农业害虫,寄主十分广泛。不同寄主植物对其生物学特性、抗寒能力的影响不同。本文从华北地区实际种植情况出发,针对由Bt棉和玉米构成的农田景观,探讨不同寄主对棉铃虫越冬抗寒的影响。首先,选择华北地区4种主要作物饲喂棉铃虫,探索不同寄主植物对棉铃虫生物学特性影响的差异性。结果显示,取食Bt棉、玉米、高粱、小麦的棉铃虫幼虫期、蛹期、蛹重、雌雄比例、化蛹率、羽化率均存在显著性差异。基于以上结果,我们进一步研究不同寄主植物对越冬代棉铃虫抗寒性的影响。通过模拟野外越冬环境,在室内饲养棉铃虫。测得取食玉米的棉铃虫滞育蛹干重、脂肪含量以及海藻糖浓度均显著高于取食Bt棉的棉铃虫滞育蛹干重、脂肪含量以及海藻糖浓度；取食玉米的棉铃虫冰点显著低于取食Bt棉的棉铃虫冰点。结果表明,取食玉米的越冬代棉铃虫抗寒能力显著强于取食Bt棉的越冬代棉铃虫。为验证这一研究结果,翌年4-5月份,我们用杨树枝在田间诱集刚羽化的越冬代棉铃虫,通过测定蛾翅的碳稳定同位素比值追溯其幼虫期(去年)的取食来源。结果表明,来自C4植物(玉米)的棉铃虫显著多于来自C3植物(Bt棉)的棉铃虫,且诱集到的越冬代棉铃虫中,雌虫多于雄虫。说明取食玉米比取食Bt棉更加有利于棉铃虫越冬抗寒。通过分析历史数据,近年来华北地区玉米种植面积不断增加,这将提高棉铃虫成功越冬比率,对棉铃虫种群扩张起到促进作用。据此,提出要更加注重玉米上棉铃虫的防治策略。
[Abstract]:Helicoverpa armigera is one of the most important agricultural pests in the world. Different host plants have different effects on their biological characteristics and cold resistance. Based on the field landscape of BT cotton and maize, the effects of different hosts on the overwintering cold resistance of cotton bollworm were studied. Firstly, four main crops in North China were selected to feed cotton bollworm (Helicoverpa armigera). The effects of different host plants on the biological characteristics of cotton bollworm (Helicoverpa armigera) were studied. The results showed that the larval stage, pupal stage, pupae weight, ratio of female to male, and rate of pupation of BT cotton, corn, sorghum and wheat fed on BT cotton, maize, sorghum and wheat were studied. Based on the above results, we further studied the effects of different host plants on the cold resistance of overwintering cotton bollworm (Helicoverpa armigera). The dry weight, fat content and trehalose concentration of diapause pupae of cotton bollworm feeding on corn were significantly higher than that of BT cotton diapause pupae, fat content and trehalose concentration. The freezing point of cotton bollworm feeding on corn was significantly lower than that on BT cotton. The results showed that the winter bollworm feeding on corn was significantly stronger than the overwintering bollworm feeding on BT cotton. We used poplar branches to lure the newly emerging cotton bollworm in the field and trace the feeding source of its larval stage (last year) by determining the carbon stable isotope ratio of moth wings. The number of cotton bollworms from C4 plants (maize) was significantly higher than that from C3 plants (BT cotton), and among the overwintering cotton bollworms, The results showed that it was more favorable for cotton bollworm to survive the winter than to eat BT cotton. By analyzing the historical data, the growing area of maize in North China was increasing in recent years, which would increase the rate of successful winter of cotton bollworm. Therefore, more attention should be paid to the control strategy of Helicoverpa armigera on maize.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S433

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