Abstract: 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.

Key words: Wheat, Twin seedlings, Type, Apomixis