氯苯胁迫对蚕豆幼苗生长和细胞分裂的影响

研究了1，2，4-三氯苯(TCB)对蚕豆幼苗生长、根尖细胞分裂及染色体畸变的影响．结果表明，随TCB浓度增加和处理时间延长，蚕豆幼苗根长的生长及根尖细胞有丝分裂指数降低甚至停止．TCB诱发蚕豆根尖细胞有丝分裂过程中染色体数目畸变和结构畸变．50-100μg.g^-1TCB胁迫12-24h，蚕豆根尖染色体的主要损伤形式为c-有丝分裂、染色体桥和不均匀排列，其出现百分率达1．0％--10.3％．300μg.g^-1TCB胁迫12-96h，蚕豆根尖细胞中染色体粘连(S)、S+染色体断裂(S+B)、S+染色体环(S+R)、S+染色体不均匀排列(S+A)及S+染色体桥(S+Be)出现的百分率达47．9％--88.9％，各种类型染色体断裂出现的百分率仅为18．1％--29．6％，说明蚕豆根尖细胞染色体畸变分析可作为TCB土壤污染监测的敏感生物监测指标．

Effects of chlorobenzene stress on seedling growth and cell division of Vicia faba

Effects of 1, 2, 4-trichlorobenzene (TCB) stress on seedling growth, cell division and chromosomal aberration frequency of root-tip cells of Vicia faba were studied. The results indicated that the growth of the root length and mitotic index of root tip cells were successively decreased and even stopped with the increase of TCB concentrations and treatment duration. Numerical and structural chromosomal aberrations at metaphase and anaphase of root-tip cells in Vicia faba seedlings were produced by 50-300 micrograms.g-1 TCB treatment for 12-96 h. The percentage of c-mitosis, chromosomal bridge and chromosomal asymmetry array in root tip cells exposed to 50-100 micrograms.g-1 TCB for 12-24 h was up to 1.0-10.3%. The percentage of chromosomal stickness (S), chromosomal stickiness + chromosomal breakage (S + B), chromosomal stickness + chromosomal ring (S + R), chromosomal stickiness + chromosomal asymmetry array (S + A) and chromosomal stickness + chromosomal bridge (S + Be) in root tip cells reached 47.9-88.9%, and 18.1-29.6% for different kinds of chromosomal breakage at 300 micrograms.g-1 TCB for 12-96 h. Thus, the chromosomal aberration of root tip cells in Vicia faba seedlings could be used as a sensitive biomarker of monitoring soil contaminated with TCB.