被子植物的无融合生殖和它的应用前景

Apomixis and Its Application Prospect

无融合生殖是植物以无性繁殖产生种子的一种生殖方式。被子植物的无融合生殖以其发生的细胞学机制分为 :未减数配子体无融合生殖 ;减数配子体无融合生殖和珠心胚结构 (或孢子体无融合生殖 )三种不同的基本类型。体细胞无孢子生殖 ,二倍体孢子生殖和珠心胚结构是被子植物常见的无融合生殖类型。这三种常见类型发生的细胞学机制和遗传特性有可能用于作物育种 ,固定杂种优势 ,因此引起了国内外植物学家和育种学家的重视。从 18世纪到现在 ,在揭示无融合生殖的细胞学机制 ,遗传特性和应用上的研究已有大量积累。近年来 ,应用分子生物学技术研究无融合生殖的细胞学过程和遗传基础也有零星报道。本文介绍 :1、无融合生殖 ;2、无融合生殖类型及其研究现状 ;3、无融合生殖的细胞学机制 ;4、无融合生殖的遗传学基础 ;5、控制无融合生殖基因转移和分子生物学研究 ;6。

Apomixis in higher plant has been defined as a vegetative method of reproductive process, which occurs in ovule and leads to seed formation. Apomictic embryo developed from somitic cell in nucellus or integumentand and without fertilization is genetically exact copies of mother, and the characteristics of Apomixis is able to transfer to offspring. Based on early origin of embryo, Apomixis of agiosperms has been divided into three different basic types, i.e. unreduced gametophytic apomixis, reduced gametophytic apomixis and adventitious embryony (or sporophytic apomixis). Apospory, diplospory and adventitious embryony are mostly common types and the most prevalent types. Because of the special cytological machenism of arising apomitic embryo and the possibility of its application in crop breeding, particularly in retaining the heterosis of hybrid, many of botanists and crop breeders have paid their attention to it since the 18th century and have now been in accumulation of a great number of knowledge in revealing the cytological events, the genetic characteristics and the partical application. In the past ten plus years, molecular biology study on apomixis has started , the focus of which lies mainly in apomictic plants of several models. The paper presents the following programms: 1. Apomixis; 2. Research progress and the type of apomixis; 3. Cytological machenism of apomixis; 4. Genetic basis of apomixis; 5. Study on transfering apomictic gene toward crop plant and molecular biology; 6. Suggestion.