水稻84—15的细胞胚胎学研究：兼论无融合生殖问题

对１３８０个水稻８４－１５子房系统的细胞胚胎学研究表明，８４－１５约９７．３％的子房内，大孢子发生及其胚囊的发育过程与普通水稻品种相似，大孢子母细胞减数分裂形成大孢子四分体，绝大多数四分体成线型排列，少数成Ｔ型排列。珠孔端的３个大孢子消失，合点端的一个为具功能的大孢子，经３次有丝分裂发育为典型的八核蓼型胚囊。在受精、胚及胚乳的发育过程中未见异常现象；约２．７％的子房内有珠心细胞、胚囊及幼胚败育等细

A Cytoembryological Study on Rice 84-15, a Rice Line Presumed to be Apomictic

Systematic Cytoembryological studies were carried out with 1380 sectinoed ovules of 84-15, a Rice line presumed to be apomitic. The results showed that megasporogenesis and embryo sac development in 97. 3% of sectoned ovules were similar to other common rice cul-tivars. The megaspore mother cell underwent meiosis to produce a linear tetrad of megaspores; a few T type tetrads were also observed. The three megaspores nearest the micropyle degenerated, leaving the chalazal megaspore as the functoinal magaspore, it enlarged and divided three times to form a mature typical eight nucleate polygonum type femal gametophyte. Fertilization and the developing process of embryo and endosperm were also normal. The phenomena of cell degenerating including that of the nucellus, embryo sacs and young embryos were observed in 2. 7% of sectioned ovules, but the cell aborted, from beginning to end, no any other phenomena of apomitic initial cells derived from differentiated within nucellus were observed. It was concluded, therefore, that 84-15 is not an apomictic rice line.