小麦与八倍体小偃麦杂种结合辐射诱导后代的细胞学分析

为了转移偃麦草属的有利基因,利用西南推广的小麦品种川麦107为母本,来源于中间偃麦草和长穗偃麦的两个八倍体小偃麦杂交所得的F1为父本。对其杂种F2代种子进行辐射处理,然后开放授粉自交多代,大群体混合选择。在F2M6世代,随机选择148个单株进行花粉母细胞减数分裂观察和分析。结果表明:在该世代染色体数目变化为41～46条,有相当一部分材料在细胞学上基本稳定,它们的减数分裂细胞中期Ⅰ中绝大多数细胞的染色体以二价体形式存在,减数分裂正常。但也有一些材料在减数分裂中期Ⅰ出现较高频率的三价体,四价体,甚至多价体,并伴随有较多的单价体,某些细胞中存在减数分裂异常现象,如染色体桥,易位环,落后染色体等,表明极有可能从这些材料中筛选出易位系。另外还分离出十多个可能的小麦-偃麦草附加系。

Cytology of the Progenies Derived from Combination of Hybrid between Wheat and Octoploid Agroticum with Radiation

The hybrid F_1 from the cross between wheat-Ag.intermedium and wheat-Ag.elongata was used as male, to transfer desirable genes of Agropyrum into the wheat variety, Chuanmai 107, recently released in southwest China. The seeds of F_2 generation were γ-radiation treated with 4?000 roentgen. The chromosomal behavior at meiosis in pollen mother cells of 148 plants from F_2M_6 progeny was observed. The results indicate that the chromosome number of observed plants ranges from 2n=41 to 2n=46, of which the plants of 2n=42 are more frequent. Most of plants with 2n=42 have stable cytology characteristics, however, trivalents, and other multivalents are also recorded at MI in other plants with 2n=42, suggesting the translocations with desirable genes might be selected from these plant progenies. In addition, more than 10 wheat-Agropyrum alien addition lines have been obtained by preliminarily cytological identification.