摘要
研究表明,毛黄鳃金龟卵在含水量为7.5%～8.2%的土壤中即可完成胚胎发育。在20℃温度中的卵,第6天(胚胎分节)～第16天(背合开始)是吸水的关键时期,在此期间,短期(3～7天)缺水,导致孵化率下降、存活卵推迟孵化,长期(12天)缺水则会对胚胎发育造成不可逆转的损伤。将胚胎发育初期的卵分别置于含水量为6.5%和7.1%的土壤中2周,发育进度与存活率均有明显差异,表明胚胎对环境含水量的微小变化是颇为敏感的。对卵壳的扫描电镜观察表明,其表面突起间的间隙有利于吸取土壤水分,而随卵体积的增大,间隙扩大,则不利于缺水时保水。
The present studies indicated that,the eggs of Holotrichia tricho- phora(Fairmaire)may complete their embryonic development in the soils with 7.5%～8.2% water content.The most important period for absorbing water is in the 6th day(segmetation period)to the 16th day beginning dorsal closure)when incubated under 20℃.During this period,a short time(3～7days)shortage of water may result in decreasing hatching rate and delaying hatching of the living eggs;while a longer time(12 days)shortage of water may irreversibly hurt the embryo.The eggs of early developing stages kept in the soils with 6.5% and 7.1% water,respectively,for two weeks showed that they were con- siderably sensitive in responding the small variation of environmental water contents as showing both in developing rate and in survival rate.An observa- tion of eggshell surface by scanning electromicroseope proved that the slits be- tween the nodules are favorable to absorbing environmental water,but disadvan- tageous in keeping water under dry condition,especially when the eggs were swollen.
基金
本课题由国家自然科学基金资助
关键词
毛黄鳃金龟
胚胎发育
土壤
含水量
Holotrichia trichophora
embryonic development
soil water content
