棉花半配合的受精生物学研究

Biological Study on Fertilization of Semigametic Cotton

本文从受精生物学角度探讨了棉花半配合特性的发生机制。发现产生半配合的棉花，受精融合过程非常特殊，主要在现在以下几点：（１）受精与胚乳形成基本正常；（２）精、卵两核接触持续４８～７２小时以上，比正常过程长约２～３倍多；（３）精、卵最终不融合，接触７２～９６小时后，两核之间出现新细胞壁，形成大型卵细胞和小型精细胞共存的原胚；（４）授粉７天后形成父母本同在的嵌合单倍体球形胚。这种精卵之间形成分隔式的半配合现象，在已研究过的具半配合植物中是没有的，也正是半配合棉花能有效地自发产生单倍体的原因。

The fertilization and pre─embryo formation of semigamy cotton was studied.Cotton bearing semigamy was extremely different from normal cotton(CK ),briefly asfollowing:(1) fertilization and endosperm formation were basically normal;(2)spermnucleus contacted with egg nucleus for 48～72 h or more,2～3 times longer than the CK;(3)affer 72～96h of such contacting,both nuclei did not fused but a new cell wall was de-veloped between them, and as a result, a pre─empryo formed with a large partion fromegg cell and a small one from sperm cell;(4) 7 days after fertilization the pre─embryodeveloped to a chimeral haploid sphere embryo derived from the parents.This phe-nomenon,in which an isolator emerged before the special embryo cell devoloped andwhich may be the reason of haploid production with high percentage from semigameticcotton, was not observed before in the otber plants bearing semigamy.