西藏小麦及半野生小麦异染色质分化的C-带研究

以Giemsa C-带技术研究了西藏小麦、西藏半野生小麦和中国春的异染色质分化。它们之间的带型没有很大的差异,但出现了C-带多态性。多态性主要表现在A、B组染色体和分布于染色体臂的中部及端部。以中国春C-带为标准的比较表明,半野生小麦的多态性所属染色体主要为A组的2A、6A和7A,B组的2B、3B、4B和7B,西藏小麦为2A、7A和7B。推测它们同属一个类群,西藏半野生小麦比西藏小麦和中国春原始,并非是来自栽培小麦的杂交后裔。

Heterochromatin Differentiation in Xizang Cultivated and Semi-wild Wheat Revealed by C-banding Technique

Heterochromatin differentiation in Chinese Spring wheat, Xizang cultivated and semi-wild wheat was investigated by C-banding technique. Although these materials had basically similar C-banding patterns, polymorphisms for C-bands in their size, total number and location were found among them. These banding polymorphisms were mainly expressed in A and B genomes, and in the intercalary regions and terminal regions of the chromosome arms. Compared with C-banding pattern of Chinese Spring, the chromosomes with C-band polymorphism were mainly 2 A, 6 A and 7 A of A genome, 2 B, 3 B, 4 B and 7 B of B genome in semi-wild wheat, and 2 A, 7 A and 7 B in Xizang wheat. The results indicated that the three wheat types were practically one species in taxa. Xizang semi-wild wheat was more primeval than Xizang wheat and Chinese Spring in evolution. It was unlikely originated from the hybridization of cultivated wheat.