温度变化对中国林蛙胚胎发育的影响

EFFECTS OF TEMPERATURE CHANGCE ON THE EARLY EMBRYO DEVELOPMENT OF Rana chensinensis DAVID

开展中国林蛙南移和人工养殖是一项很有意义的工作，而南方多变的气温是否影响其胚胎发育是一个尚未研究的课题。本文利用受精卵在不同温度的恒温培养箱间移换，研究了温度变化对中国林蛙早期胚胎发育的影响，结果表明：（１）快速升温对中国林蛙胚胎孵化率、正常率均有影响，且温差越大影响越大；缓慢升温对胚胎的影响与温差大小和升温起点有关，高起点的升温对胚胎的影响比低起点的升温更大，生产中快速升温以不超过２℃，慢速升温以不超过４℃为宜。（２）慢速降温幅度为４℃时，对胚胎发育无影响，为８℃时，有影响；快速降温幅度为４℃时，对胚胎孵化率和正常率均有影响，生产中慢速降温以不超过８℃，快速降温以不超过４℃为宜。（３）变温幅度相同时，变温速度越大，对胚胎的影响越大。（４）原肠期是中国林蛙胚胎发育的升温敏感期，神经管期为升温非敏感期，中国林蛙胚胎发育中对升温变化较降温敏感。（５）中国林蛙的胚胎发育不会因南方天气的异常而遭到严重的影响。

It is very promising to develop Rana chensinensis David breeding in South China. Whether the changeable air temperature of the South has an effect on it′s embryo development isuncertain. We studied the effects of temperature change on early embryo developmentby moving fertilized eggs between incubators of different temperatures.The results showed;(1)Rapid temperature increase had a harmful influence on hatching and normal rates of theembryos, and the wider the temperature span was,the more harmful the impact was. Effectsof moderate temperature increase on embryos were hinged upon the temperature span and starting point. High starting temperature was more harmful.In commercial production, rapidtemperature increase should be within 2℃,moderate increase should be within 4℃.(2)Inmoderate temperature decrease, a span of 4℃ had no influence,but an 8℃ decrease was detrimental.If rapid temperature decrease span was 4℃,both hatching and normal rates wereimpaired.In commercial production, moderate temperature decrease should be within 8℃and rapid decrease should be within 4℃.(3)When the change spans were the same,thequicker the change was, the more harmful the impact was.(4)The Gastrula Stage was thetime when embryos were sensitive to temperature increase,and the Neural Canal Stage wasnot.Embryos were more sensitive to temperature increase than to decrease.(5)No seriousharm would be imposed upon Rana chensinensis David embryos in development by thechangeable climate of South China.