寄主植物、温度对金银花尺蠖幼虫消化酶活性的影响

  目的  通过研究寄主植物、温度对金银花尺蠖Heterolocha jinyinhuaphaga幼虫消化酶活性的影响，为深入研究金银花尺蠖环境适应性的生理生化机制奠定基础。  方法  采用3，5-二硝基水杨酸法、福林-酚法和标准氢氧化钠溶液滴定法，通过分光光度计和滴定管测定了寄主植物、温度对金银花尺蠖幼虫消化酶活性的影响。  结果  取食3个金银花Lonicera japonica品种‘九丰1号’‘Jiufeng No.1’、‘响水1号’‘Xiangshui No.1’、‘响水2号’‘Xiangshui No.2’和野生金银花后，金银花尺蠖各龄幼虫消化酶活性均不一样。取食野生金银花的金银花尺蠖淀粉酶、蔗糖酶和蛋白酶活性均最高，脂肪酶活性最低，在1龄幼虫中4种消化酶的活性分别为18.37、26.45、22.31和5.54 mmol·g-1·min-1。4种消化酶活性均随着幼虫龄期的增加而增大，取食4种金银花后5龄幼虫的淀粉酶活性分别比1龄幼虫增加了33.39%、27.48%、33.31%和45.29%，蔗糖酶活性分别增加了19.12%、15.02%、14.64%和29.64%，蛋白酶活性分别增加了25.55%、18.69%、21.69%和41.46%，脂肪酶活性分别增加了84.95%、68.04%、68.41%和77.80%。在16~34℃，4种消化酶活性均随着温度的升高表现为先上升后下降的趋势，1~5龄幼虫的淀粉酶活性在22℃最高，分别为19.95、20.57、21.79、23.64和25.86 mmol·g-1·min-1；1~5龄幼虫的蔗糖酶活性在22℃最高，分别为27.65、28.89、29.85、31.45和32.89 mmol·g-1·min-1；1~5龄幼虫的蛋白酶活性在25℃最高，分别为21.65、22.76、23.43、25.71和26.98 mmol·g-1·min-1；1~5龄幼虫的脂肪酶活性在28℃最高，分别为7.38、8.49、9.81、11.33和13.21 mmol·g-1·min-1。方差分析显示:寄主植物和幼虫龄期的交互作用，以及温度和幼虫龄期的交互作用对金银花尺蠖幼虫4种消化酶活性均没有显著影响。  结论  寄主植物、温度能影响金银花尺蠖幼虫消化酶的活性。

Effects of host plants and temperatures on digestive enzyme activities in Heterolocha jinyinhuaphaga larvae

  Objective  This research aims to study the effects of host plants and temperatures on digestive enzyme activities in Heterolocha jinyinhuaphaga larvae, and lay a foundation for further research on their physiological and biochemical mechanism of environmental adaptation.  Method  Effects of these factors on digestive enzyme activities in H. jinyinhuaphaga larvae were studied through ultraviolet spectrophotometry and burette in laboratory by using 3, 5-dinitrosalicylic acid method, fulin-phenolic method, and standard sodium hydroxide solution titration method.  Result  Digestive enzyme activities of each H. jinyinhuaphaga larva differed after feeding on 'Jiufeng No. 1', 'Xiangshui No. 1', 'Xiangshui No. 2' and a wild variety of Lonicera japonica. The H. jinyinhuaphaga larvae feeding on the wild variety had the highest amylase, sucrase and protease activities, and the lowest lipase activity. The activities in the 1st instar larva were 18.37, 26.45, 22.31 and 5.54 mmol·g-1·min-1 respectively. The four digestive enzyme activities all increased with larval ages. Compared with the 1st instar larvae, the 5th instar larvae, after feeding on the four cultivars, displayed an increase in amylase activities by 33.39%, 27.48%, 33.31% and 45.29%, an increase in sucrase activities by 19.12%, 15.02%, 14.64% and 29.64%, an increase in protease activities by 25.55%, 18.69%, 21.69% and 41.46%, and an increase in lipase activities by 84.95%, 68.04%, 68.41% and 77.80%. In the range of 16-34℃, the activities of the four digestive enzymes all showed a tendency of first increasing and then decreasing with the rise of temperature. The highest amylase activities were observed at 22℃ in the larvae of the 1st-5th instar, which were 19.95, 20.57, 21.79, 23.64 and 25.86 mmol·g-1·min-1. The sucrase activities of the 1st-5th instar larvae were the highest at 22℃, which were 27.65, 28.89, 29.85, 31.45 and 32.89 mmol·g-1·min-1. The protease activities of the 1st-5th instar larvae were the highest at 25℃, which were 21.65, 22.76, 23.43, 25.71 and 26.98 mmol·g-1·min-1. The lipase activities of the 1st-5th instar larvae were the highest at 28℃, which were 7.38, 8.49, 9.81, 11.33 and 13.21 mmol·g-1·min-1. Two-way ANOVA showed that the interaction between host plants and larval ages, as well as the interaction between temperatures and larval ages, had no significant effect on the four digestive enzyme activities.  Conclusion  Host plants and temperatures can affect digestive enzyme activities of H. jinyinhuaphaga larvae.