意大利蝗不连续气体交换循环(DGC)呼吸周期历时对高温胁迫的响应

【目的】在前期研究高温胁迫下意大利蝗Calliptamus italicus呼吸代谢的变化特征基础上,为探明相关变化机制,本研究进一步从不连续气体交换循环(DGC)呼吸周期历时阐明其对高温胁迫的响应机制。【方法】以源自新疆伊犁察布查尔蝗区野生种群的意大利蝗成虫为材料,应用多通道昆虫呼吸仪测定意大利蝗DGC暴发间期、暴发期和呼吸周期三者历时随温度变化(21~42℃区间,3℃温度梯度)的响应特征。【结果】雌雄意大利蝗DGC呼吸周期中暴发间期历时随温度升高而缩短,21℃时暴发间期历时最长,雌雄分别为7.29±0.31和7.05±0.37 min,与24,27,30和33℃差异不显著(P0.05),超过33℃后迅速缩短;至39℃时最短,雌雄分别为0.42±0.01和0.70±0.03 min,与其他温度下的历时差异显著(P0.05)。暴发期历时亦随温度升高而缩短,21和39℃时,雌虫暴发期历时分别达到最长和最短,依次为1.55±0.14和0.45±0.01 min,与其他温度下的历时差异显著(P0.05);24和39℃时,雄虫暴发期历时分别达到最长和最短,依次为1.61±0.10和0.68±0.02 min,与其他温度下的历时差异显著(P0.05)。随温度升高,意大利蝗DGC呼吸周期历时呈减少趋势,且主要由暴发间期历时减少所致。21~33℃范围内,每升高3℃雌雄虫暴发间期历时分别平均减少0.174和0.121 min,DGC呼吸频率增幅一致,均为0.0022 Hz,不同温度间差异不显著(P0.05);超过33℃后,每升高3℃雌雄虫暴发间期历时分别平均减少2.197和2.189 min,DGC呼吸频率分别增加0.0120和0.0085 Hz,不同温度间差异显著(P0.05);39℃时暴发间期历时接近零,42℃时DGC呼吸模式消失。【结论】随温度升高,意大利蝗呈现出O2吸收量和CO2释放量增加的变化特征,这是通过减少暴发间期历时和增加DGC呼吸频率等机制而实现的。

Response of the discontinuous gas exchange cycle (DGC) duration in Calliptamus italicus (Orthoptera: Acrididae) to high temperature stress

Aim] Based on our previous studies of the effects of high temperature stress on the respiratory metabolism of Calliptamus italicus,this study aims to determine the response of the discontinuous gas exchange cycle (DGC) duration in C.italicus to high temperature stress.Methods] We examined the interburst duration,burst duration and DGC duration of C.italicus adults by using Sable Systems in the temperature range from 21 to 42℃ at 3℃ intervals.Results] The interburst and burst durations decreased as the temperature went up.The interburst duration did not significantly change at temperatures lower than 33℃ (P ＞ 0.05),whereas it rapidly shortened at temperatures over 33℃ and was significantly shorter at 39℃ than at other temperatures (P ＜ 0.05).The burst duration was the longest at 21℃ and the shortest at 39℃ for females,whereas it was the longest at 24℃ and the shortest at 39℃ for males.The DGC duration decreased and the DGC frequency increased as the temperature went up.The interburst durations from 21 to 33℃ were not significantly different (P ＞ 0.05) between females and males,decreasing by 0.174 and 0.121 min per 3℃,respectively.The DGC frequency changes for females and males were similar at temperatures lower than 33℃,increasing by 0.0022 Hz per 33℃.Interburst durations significantly decreased at temperatures over 33℃ for females and males by 2.197 and 2.189 min per 33℃,respectively,but the DGC frequency increased by 0.0120 and 0.0085 Hz per 3℃,respectively.The interburst duration was close to zero at 39℃,and the DGC breathing pattern completely disappeared at 42℃.Conclusion] With temperature rising,both the O2 uptake rate and CO2 release rate increase in C.italicus,which is realized by decreasing the DGC duration and increasing the DGC frequency.