N^+离子引起的黑麦染色体易位

Chromosome Translocation in Rye Induced by Nitrogen Ion Beam Irradiation

离子注入黑麦的生物效应,有生理变异,也有遗传变异;经过低能N^+离子束辐照,选出黑麦284-2,其减数分裂的染色体观察,在中期Ⅰ和终变期,所有细胞均出现一个相邻式环状四价体或交替式∞状四价体,其比例为1:1,M_1代体细胞染色体出现两对染色体畸变,经C分带的带型分析,获得了1R和4R的染色体易位。本文还提出了黑麦284-2由杂合易位体获得纯合易位体的途径,探讨了离子束辐照诱变植物的机理。

Irradiation with ion beam could cause both physiological and genetic variations.After the seeds of a pure line of rye, AR132, Were irradiated with N^+ ion beam, anabnormal individual plant, 284--2, was found whose morphological characters werequite different from those of the others. Microscopic observation at the MI anddiakenesis of mdosis revealed that while there were usually 7 bivalents in the cells ofmost of the treated plants and the check, there were only 5 bivalents and onetetravalent in those of 284--2. There were 2 types of tetravalent configurations: the 0type configuration caused by adjacent disjunction and the ∞ type configuration causedby altemative digjunction. The ratio of these 2 types was 1:1, indicating translocationbetween 2 non- homologous chromosomes. Results of C-banding analysis revealed thatthe translocation happened. between the 1R and the 4R chromosomes. The approach to obtain homozygous translocation from heterzygous translocationin rye as well as the mechanism of the induction of variation through irradiation withion beam in plant were also discussed.