小麦-冰草二体附加系的细胞学稳定性研究

Cytological Stability of Wheat-Agropyron Cristatum Gaertn Chromosome Disomic Addition Lines

为了研究小麦-冰草二体附加系的细胞学稳定性,采用细胞遗传学技术,对20个小麦-冰草二体附加系开放授粉后代的染色体数目进行了分析。结果表明,在所检测的20个二体附加系后代中,细胞学稳定性存在较大的差异:在10份材料中检测到2n=44植株的平均频率为74.78%,传递率为33.3%～100%;在10份材料的后代植株中没有检测到2n=44的植株,通过GISH分析,在这些后代中检测到1个代换系5111-1和1个易位系5112-4。说明在二体附加系后代中2n=42的个体,并不一定表示冰草染色体的完全丢失,而可能以其它形式(如代换、易位等)存在于小麦核背景中。同时,还讨论了冰草属P基因组在小麦族中的地位。

In order to understand the cytological stability of (chromosome) addition lines, the root tip (chromosome) numbers in open-pollinated (progenies) of 20 wheat-Agropyron cristatum (chromosome) addition lines were analyzed. Among the 20 disomic addition lines, cytological stability differed greatly. In the (progenies) of 10 lines, transmitting rates of 2n=44 plants were 33.3% to 100%, with the average of (74.78%). In the (progenies) of the remaining 10 addition lines, no plants with 2n=44 (chromosomes) were observed. However, with genomic in situ hybridization (GISH) analysis, one translocation line, (5112-4) and one substitution line 5111-1, between A. cristatum and wheat (chromosomes) were recovered from the 2n=42 plants. These results suggested that (progenies) with 2n=42 (chromosome) numbers of those (addition) lines do not mean the complete lost of alien (chromosomes), but may substitute for or be translocated to the (chromosomes) of wheat. In (addition), the facts that P-genome spontaneously translocated to the (chromosomes) of (St-genome) in genus Kengyilia Yen et J. L Yang, also suggested that P genome in the Tribe Triticeae should be understood anew.