【摘要】 研究了镉(Cd)对水稻幼苗生长、根尖细胞有丝分裂及染色体畸变的影响。结果表明,随着Cd浓度增加和处理时间延长,水稻幼苗根的生长及根尖细胞有丝分裂指数明显降低。Cd使有丝分裂中期细胞所占比例相对增加,前期、后期、末期细胞相对减少。Cd能诱导染色体产生多种类型的畸变,染色体畸变率随着Cd处理浓度的增加和处理时间的延长而升高,呈现明显的剂量-效应和时间-效应关系。1～10μmol L-1Cd胁迫24 h后,水稻根尖畸变主要有C-有丝分裂、染色体桥,占总畸变率的32.64%～78.29%;25～200μmol L-1Cd胁迫24～72 h后,水稻根尖细胞中染色体粘连、断片和微核占较大比例,占总畸变率的76.44%～93.96%。研究表明,Cd对水稻根尖分生细胞有丝分裂具有阻滞作用,并诱发染色体畸变率的显著升高。更多还原

【Abstract】 A study was carried out to investigate effects of cadmium stress on growth of rice seedlings,mitosis and chromosomal aberration of root tip cells.Results show that root elongation and the mitotic index of the root tip cells were significantly decreased with the increasing Cd concentration and treatment duration.Cd increased the proportion of metaphase cells,while decreasing those of prophase,anaphase and telaphase cells.Cd induced chromosomal aberrations of different types of root tip cells at their metaphase and anaphase,with frequency rising with Cd concentration and treatment duration.C-mitosis and chromosomal bridge were the main types of chromosomal aberration in root tip cells exposed to 1~10 μmol L-1 Cd for 24 h,accounting for 32.64%～78.29%,while the percentage of chromosomal adhesion,chromosomal breakage and micronuclei for 76.44%～93.96% in root tip cells exposed to 25~200 μmol L-1 Cd for 24~72 h.All these results suggest that Cd obviously retards mitosis and induces chromosomal aberration in root tip cells of rice seedlings.更多还原