The Cold-hardiness of different geographical populations of the Migratory Locust, Locusta migratoria L. (Orthoptera, Acrididae)
The Cold-hardiness of different geographical populations of the Migratory Locust, Locusta migratoria L. (Orthoptera, Acrididae)
复制标题
飞蝗不同地理种群的抗寒性（直翅目、蝗科）
作者：
Bingxiang Li;Yonglin Chen;Huiluo Cai
过冷点（SCP）随着三个地理种群的发展而增加。三个群体I、II、III胚胎期的SCP分别约为-28℃、-20℃和-9℃。和硕种群成虫的SCP低于北大港种群成虫。在所有胚胎阶段，低温驯化都会导致糖原分解以合成冷冻保护剂，并且最高合成发生在第二阶段胚胎。甘油和山梨醇是和硕人群胚胎中的主要冷冻保护剂，但海藻糖是哈密人群胚胎中的主要冷冻保护剂，同时在哈密人群的鸡蛋中也发现了这三种冷冻保护剂。由于糖原含量随着胚胎发育而降低，胚胎后期的低糖原水平成为冷冻保护剂合成的限制。随着胚胎发育而减少的GPase整体含量在应激中保持稳定。冷激（2小时）使GPase增加约10%~40%。热休克导致的活动增加与北大港和哈密人群的鸡蛋渴望的冷休克相似。仅在和硕群体的Ⅲ胚期，热休克导致GPase‘a’的变异更为显着。
The supercooling point(SCP) increases with development in the three geographical populations. The SCPs in the I, II and III embryo stages of the three populations are about -28℃, -20℃ and -9℃ respectively. The SCP of the adults from the Heshuo population is lower than that in the adults from the Beidagang population. Low temperature acclimation leads the glycogen breakdown to synthesize cryoprotectants in all embryo stages, and the highest synthesis occurred in the stage II embryo. Glycerol and sorbitol are the dominant cryoprotectants in the embryo of the Heshuo population, but trehalose is the principal one in the embryo of the Hami population, in the same time all the three kinds were found in eggs of the Hami population. For the decreasing content of glycogen with the embryo development, the low glycogen level in the late embryo stage becomes the limitation to the cryoprotectants synthesis. The whole content of the GPase that reduces with the embryo development keeps stable in the stress. Cold shock(2 hours) leads the GPase to ‘a' increase of about 10%~40%. Heat shock shaped the activity increase is similar to the cold shock craved in the eggs from the Beidagang and the Hami populations. Only in the Ⅲ embryo stages of the Heshuo population, heat shock reasons more significant variation of the GPase ‘a'.