外源DNA导入小麦后雄性不育变异的初步研究

PRELIMINARY STUDIES ON MALE STERILE MUTANT AFTER EXOGENOUS DNA INTRODUCED INTO WHEAT

利用浸泡法将外源λDNA导入普通小麦品系 81 45 2 7,获得不育变异株 ,稳定为不育系 ,简称D型不育系。该不育系小花结构具有显著特点 ,多数小花子房数目增加 ,花药数目减少 ,而且二者之和并非恒定为 4。多子房小花一般位于穗的中部 ,而顶部和基部小花未发现多子房现象。多子房小花的主子房位于小花的中央 ,副子房着生于主子房的周围。子房的发育进程不同步 ,主子房发育较早 ,体积较大 ;副子房发育较慢 ,而且未发育成熟即退化萎缩。花药多呈短棒状、月牙状等畸形状态 ,且多数在早期即退化萎缩 ,无生活力花粉。杂交试验表明 ,该不育系为细胞质雄性不育系 ,不育度达 99% ,受体品系 81 45 2 7可作其保持系。不育系与鲁麦 1 4号的杂种一代在穗长、每穗小穗数和穗粒数等性状上存在一定程度的杂种优势 ,单株产量较鲁麦 1 4号增加 1 1 6%。

A stable sterile line—D-type sterile line was obtained after exogenous λDNA introduced into wheat line 814527. There were obvious characters in flower structure of the sterile line. The number of ovaries increased and that of anthers declined, and the sum was not always equal to four. Polygynous flowers were located in the middle of panicles, while there were no polygynous ones on the top and the base of panicles. The main ovary was in the center of the flower, and the accessory ovaries surrounded the main ovary. The ovaries did not develop synchronously, main ovary developed earlier and accessory ones slower. The volume of main ovary was bigger than the accessory ones. Anthers of the sterile line with abnormal shapes were obsolescent at early stage, and had no living pollen. It showed that the sterile line was a cytoplasmic male sterile one, and the acceptor line 814527 could be its maintainer. The hybrid of the sterile line and Lumai 14 had some heterosis in traits such as panicle length, spikelet number per panicle and grain number per panicle, and its yield per plant was 11.6% higher than that of Lumai 14.