温度对中华蜜蜂和意大利蜜蜂个体主要抗寒生理指标的影响

Effects of temperature on major physiological indicators of cold tolerance in Apis cerana cerana and Apis mellifera ligustica

【目的】为了探究中华蜜蜂Apis cerana cerana和意大利蜜蜂Apis mellifera ligustica个体耐寒性差异的生理机制。【方法】本试验分别对20日龄的中华蜜蜂和意大利蜜蜂工蜂进行0、10、25℃持续4 h的温度处理,随后测定不同温度处理后两蜂种体内葡萄糖、甘油和氨基酸的含量。【结果】低温状态下中华蜜蜂体内葡萄糖含量显著降低,意大利蜜蜂在0℃组显著下降却在10℃组显著上升;中华蜜蜂体内甘油在低温环境下显著积累,意大利蜜蜂体内甘油水平在10℃时显著的上调却在0℃组无显著变化;中华蜜蜂体内17种氨基酸在各温度处理间显著变化,且多数的氨基酸含量表现出10℃组降低而0℃组积累的趋势,意大利蜜蜂体内只有15种氨基酸参与机体的抗寒机制,其中多数的氨基酸表现为低温环境下大量积累,仅有亮氨酸和精氨酸表现为低温时被转化消耗的现象。【结论】低温条件下可引起两蜂种体内葡萄糖、甘油和氨基酸含量的显著变化,初步推测蜜蜂体内可能存在"葡萄糖-甘油-氨基酸"的抗寒物质系统,但两蜂种在不同程度的低温处理后各生理指标的变化存在较大的差异,从一定程度上阐释两蜂种抗寒性的差异。本研究为蜜蜂个体抗寒生理机制的进一步研究提供基础数据,同时为蜜蜂抗寒新品系的选育提供理论依据。

[Objectives] To investigate the physiological mechanisms responsible for differences in cold tolerance between Apis cerana cerana and Apis mellifera ligustica. [Methods] Twenty-day old adult worker bees of each species were exposed to either 0 ℃, 10 ℃ and 25 ℃ for 4 h in a constant temperature and humidity incubator after which their glucose, glycerin and amino acid content was detected. [Results] The glucose content of A. c. cerana decreased significantly at 0 ℃ and 10 ℃ whereas that of A. m. ligustica decreased in the 0 ℃ treatment group but increased in the 10 °C treatment group. Glycerin content increased with at 0 ℃ and 10 ℃ in A. c. cerana but increased in the 10 °C treatment group, and underwent no significant change in the 0 ℃ group, in A. m. ligustica. Temperature significantly affected amino acid levels in A. c. cerana; 16 of the 17 amino acids measured declined in the 10 ℃ group and increased in the 0 ℃ group. In contrast, levels of only 15 amino acids changed dramatically with temperature in A. m. ligustica. Most amino acids increased as temperature decreased, except leucine and arginine which decreased at low temperatures. [Conclusion] Levels of glucose, glycerin and amino acids were significantly affected by temperature, which suggests that there may be a "glucose-glycerin-amino acid" system that enhances cold hardiness in A. c. cerana and A. m. ligustica. The different effects of temperature on levels of these cryoprotectants in these two species may to some extent explain their different degrees of cold tolerance. This study provides a foundation for further study of the physiological mechanisms underlying cold tolerance in honey bees, and a theoretical basis for breeding of new, more cold-resistant strains.