胚带

本文详细研究了甜菜夜蛾Spodopteraexigua（H櫣bner）胚胎发育的卵裂、胚盘、胚带的形成和胚层分化。

This paper studies the embryonic development of Spodoptera exigua ( H ü bner ) including the cleavage , the formation of blastoderm and germ band , and the differentiation of germinal layers .

卵腹面的胚盘细胞逐渐增厚为胚带，其他胚盘细胞发育成浆膜，浆膜刚一形成，羊膜即开始发生；

The blastoderm cells on the egg venter developed into germ band , the other cells into serosa . The amnion began to grow shortly after the formation of serosa .

根据其胚胎外形的发育特点，可将整个发育期分为5个阶段：早期发育阶段、胚带伸长阶段、胚胎缩短阶段、胚胎翻转及背合阶段、胚胎再伸长成熟阶段。

According to the characters of embryo shape , the whole embryonic development of the beet armyworm could be divided into five phases : the phase of early developing , germ band elongating , embryo shortening , embryo reversing and dorsal enclosure , embryo elongating again and maturing .

研究了分割所用溶液、冷冻前胚胎发育时期和分割后将半胚是否装入透明带对冻胚分割效果的影响。

Effect of solution used for bisection , embryo development before freezing and coating demi-embryos with or without zona pellucida ( ZP ) after bisection on bisection of frozen-thawed embryos was studied .

试验结果表明，影响高剂量辐射花粉技术生产苹果单倍体效率的主要因素是早期落果、幼胚败育和带胚乳幼胚不能培养再生植株。

The investigation indicated that major factors which limited hapliod production efficiency in apple by such technique included abscission of fruits in early stage , young embryo abortion and difficulty in regeneration of young embryo with endosperm .

胚基具有生长带，纵向伸长长度大，胚基的上部参与形成胚根鞘，其余部分干缩后附在胚根鞘末端。

As to the hypoblast there is a growth belt , which promotes elongation of the hypoblast . Eventually the upper portion of the hypoblast contributes to the formation of the coleorhiza and the remainder dries up , sticking to the end of the coleorhiza .