复合四倍体异育银鲫两种不同生殖方式的细胞学观察

在复合四倍体异育银鲫（）×银鲫（）的受精过程中，精子入卵后经过解凝、核化，最终形成雄性原核，并可与卵子的雌性原核融合，证明了复合四倍体异育银鲫卵子具有与两性融合生殖极为相似的拟两性融合生殖的能力；而在复合四倍体异育银鲫（）×兴国红鲤（）的组合中，精子入卵后以固缩状态存在，又表现出典型的雌核发育型生殖行为。因此我们认为复合四倍体异育银鲫具有两种不同的生殖发育机制。此外，我们还观察到在第一次有丝分裂中期有核物质被排斥到纺锤体之外的现象。本文就复合四倍体异育银鲫生殖发育的机制进行了初步的探讨。

CYTOLOGICAL STUDIES ON TWO DIFFERENTAL DEVELOPMENT MODES OF THE ALLOGYNOGENETIC SILVER CRUCIAN CARP MULTIPLE TETRAPLOID

The present paper reports different development modes in the eggs of the allogyno- genetic silver crucian carp,which was found in the artificial breeding population of Carassius auratus gibelio ( ) X Cyprinus carpio red variety ( ). The development process of two groups, mutiple tetraploid allogynogenetic silver crucian carp () X crucian carp (Carassius auratus gibelio) ()and multiple tetraploid allogynogenetic silver crucian carp( ) X red carp ( ),were observed. It was found that,in the 2nd group,the sperms of the red carp do not decondense and transform into a male pronucleus after having penetrated into the ovum of the mutiple tetraploid allogynogenetic silver crucian carp (plate II ). That is a typical process of allogynogenesis. However, in the first group,the sperms of crucian carp have general process of decondensation formation of pronucleus and conjoint with the female pronucleus. It is so similar to the process of the amphimixis that We call it pseudoamphimixis temporarily (Plate I, )Moreover in the Ist group,it has been found in most sections that some of chromer somes had been excluded outside when the most of chromosomes had been arranged at the equator of the spindle at midstage of the first cleavage of fertilized eggs. The mechanism of allogynogenesis in the eggs of mutiple tetraploid allogynogenetic silver crucian carp is discussed.