小麦双胚苗类型及后代观察初报

对小麦与天蓝偃麦草杂交诱导后代筛选的36个双胚苗株系进行形态特性分类.共有6种,即双鞘同步型.双鞘异步型,单鞘同步型.单鞘一叶重叠同步型.单鞘一叶共生同步型、单鞘异步型,小麦双胚苗二代再现双苗率极小,三代双胚苗两苗系再现频率分别为0.823%和0.139%.二代分离奇异,三代按株系趋向整齐.双胚苗及后代去雄套袋有不同程度的自主结实特性.是有性和无性基因型细胞的嵌合体,双苗特性可通过有性或无性过程传递给后代,无性的表达可能需特定的环境条件.双胚苗是选择兼性或专性无融合生殖的一个中间型桥梁材料.

Initial Observation Report about Types and Progenies of Wheat Twin Seedling

36 wheat twin seedling strains derived from filial genetations of wheat xagropy-onglaucum were lassified according to morphological characters. There are 6 types: the double -sheath synchronous type,the double -sheath asynchronous type,the single -sheath synchronous type ,the single -sheath and the -first - leaf - overlapping synchronous type,the single -sheath and the - first - leaf -symbiosis synchronous type,and the single -sheath asynchronous type. The rate of twin seedlings in the second generation was very low. In the third generation, the rate of twin seedlings of 2 strains were separaely, the rate of twin seedlings of 2 strains were 0. 823% and 0. 139% respectively. The second generation showed a peculiarsegregation. The third generation tended to uniformity. Twin seedling and their progenies showed self-fertile characters. Twin seedlings were chimeras of sexual and asexual cells . The character of twin seedlings can be transferred to the progeny through sexual methods. The asexual expression may probably need special environmental conditions. Twin seedlings are an intermediate material for facultative or specific apomixis.