雌雄意大利蝗耐高温差异及其生理生化响应对策
Differences in heat tolerance and physio-biochemical mechanisms between adult female and male Calliptamus italicus (Orthopera:Acrididae)
李 爽** 王冬梅 李 娟 扈鸿霞 季 荣***
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DOI：10.7679/j.issn.2095-1353.2015.115
作者单位：新疆师范大学生命科学学院， 新疆特殊环境物种保护与调控生物学实验室， 中亚区域跨境有害生物联合控制国际研究中心，乌鲁木齐 830054
中文关键词：意大利蝗，高温耐受，死亡率，抗逆保护物质
英文关键词：Calliptamus italicus (L.),heat tolerance,mortality,stress resistant substances
中文摘要：
【目的】 意大利蝗Calliptamus italicus (L.)是新疆荒漠、半荒漠草原优势危害种类之一，前期研究表明其发生与新疆同期气候变暖显著相关，且野外自然种群雌性个体数量明显多于雄性。本研究进一步探讨了雌雄意大利蝗高温耐受性差异及其生理生化机制。【方法】 采用生理生化研究方法，研究了在27、30、33、36、39、42、45和48℃不同温度处理下，雌雄意大利蝗体内自由水/结合水、海藻糖、游离蛋白质、不饱和脂肪酸（油酸、亚油酸和亚麻酸）6种抗逆保护物质的含量变化。【结果】 不超过39℃时，雌雄死亡率差异不显著（P＞0.05），超过39℃后雄虫死亡率显著高于雌虫（P＜0.05），51℃时死亡率达到100%；随温度升高，雌雄意大利蝗体内6种物质的含量均呈先增后减的变化趋势。但不同温度处理下，雌雄成虫的自由水/结合水比值差异均不显著（P＞0.05），海藻糖、油酸的含量差异均显著（P＜0.05）。除45℃，雌雄体内亚麻酸的含量差异均显著（P＜0.05）；除27℃、48℃，雌雄体内游离蛋白质含量差异均显著（P＜0.05），亚油酸的含量变化则无明显规律。不同温度胁迫下，雌雄意大利蝗体内6种物质增减速率不同，以不饱和脂肪酸物质积累速率最大，分别为82.53%（雌）、117.13%（雄）。【结论】 雌、雄意大利蝗个体可通过积累不同种类的抗逆保护物质，以度过阶段性高温胁迫，且雌性具有较强的高温耐受能力。
英文摘要：[Objectives] Calliptamus italicus is a major plague pest species in the arid and semi-arid grasslands of Xinjiang. Previous studies claimed that outbreaks of this pest were closely related to climate warming in Xinjiang since the 1980s. Females outnumbered males in natural populations. This study aimed to explore differences in heat tolerance between adult females and males, including the physiological and biochemical mechanisms underlying these differences. [Methods] The free water/combined water, trehalose, soluble protein, oleic acid, linoleic acid and linolenic acid content of females and males was measured after adults were placed into a climate cabinet under consistent temperature regimes of 27-48℃at 3℃ intervals for 4 h. [Results] Mortality of females and males did not significantly differ when exposed to < 39℃ (P＞0.05), whereas the mortality of males was significantly higher than that of females when exposed to temperatures > 39℃ (P＜0.05). Mortality of both sexes reached 100% at 51℃. The contents of the six stress resistant substances in females and males showed a trend of first increasing, then decreasing, with temperature. Although the free water/combined water ratios of females and males were not significantly different under different temperatures (P＞0.05), their trehalose and oleic acid contents were significantly different (P＜0.05). The linolenic acid content of females and males was also significantly different (P＜0.05) at all temperatures other than 45℃, and soluble protein content was also significantly different between the sexes (P＜0.05) at all temperatures other than 27℃ and 48℃.There was no apparent regulation of the change in linoleic acid content. The accumulation rates of the six stress resistant substances differed with temperature; unsaturated fatty acids had the highest accumulation rate, peaking at 82.53% and 117.13% for females and males, respectively. [Conclusion] C. italicus can adapt to higher temperatures by accumulating stress resistant substances, and females have higher capacity for heat tolerance than males.