铬(Cr^(6+))胁迫对蚕豆幼苗根生长和细胞分裂的影响  

Effect of Cr^(6+) Stress on Seedling Root Growth and Cell Division of Vicia faba

作　　者：王爱云[1] 夏文睿[1] 荣玮[1] 刘茜[1] 

机构地区：[1]中南林业科技大学生命科学与技术学院,长沙410004

出　　处：《西北农业学报》2012年第6期79-85,共7页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：湖南省科技厅项目(2011NK3037);湖南省发改委项目(湘发改高技[2011]1318号);中南林业科技大学引进人才科研启动基金项目(104-0128);中南林业科技大学林木遗传育种学科建设项目

摘　　要：为了阐明Cr6+胁迫对蚕豆根尖分生组织细胞的遗传毒害效应,研究Cr6+胁迫对蚕豆种子萌发、幼苗根生长、根尖细胞分裂及染色体畸变的影响。结果表明,低质量浓度Cr6+促进蚕豆种子萌发,而高质量浓度Cr6+有抑制作用,并且随着处理时间的延长,其最适质量浓度降低。当Cr6+质量浓度超过10mg/L时,蚕豆幼苗根的生长明显受到抑制,并且呈现时间效应关系。外部形态上,高质量浓度Cr6+导致蚕豆根明显弯曲,根尖呈现褐色、深褐色,甚至黑色,部分开始硬化。当Cr6+质量浓度≥5mg/L时,随着Cr6+质量浓度的增加,处理时间的延长,蚕豆根尖细胞有丝分裂指数下降,且表现明显的剂量效应和时间效应关系,进入细胞分裂前期、后期和末期的细胞明显减少,而中期细胞所占的比例上升。同时染色体产生染色体断片、染色体桥、落后染色体、染色体粘连及多极分裂等各种类型的畸变,但以染色体断片为主,其次是微核。当Cr6+质量浓度≤100mg/L时,随着Cr6+质量浓度的增加和处理时间的延长,蚕豆根尖细胞微核率增加;但当Cr6+质量浓度为200mg/L,处理超过48h后,随着处理时间的延长,其微核率反而下降。In order to elucidate the genetic toxicity of chromium（Cr6＋） stress for root tip cells of V. faba , the experiment was conducted to investigate the effects of Cr6＋ on seed germination, seedling root growth, root tip cell division and chromosomal aberration. The results indicated that the seed germination rate of V. faba was increased under lower Crs＋ mass concentrations. However, the seed germination were restrained at higher Crs＋ concentration, and the feasible Cr6＋ mass concentra- tions was decreased with the treatment duration prolonged. The root growth was obviously inhibited when the Cr6＋ mass concentration was above 10 rag/L, and the connection between time and effect could be observed. The obvious morphological changes were found under higher Cr6＋ mass concentrations： the twisted roots, brown, black brown, even black spots in root tips and partially hardened roots. With the Cr6＋ mass concentration （5 mg/L ） increased and the treatment duration prolonged, the mitotic index of root tip cell was decreased, and there was obviously time-effect connection between doses and effect. The proportion of mitotic metaphase cells was relatively increased, while decreasing those of prophase, anaphase and telaphase cells in root tips of V. faba. Cr6＋ stress could induce the occurrence of structural chromosomal aberrations, including chromosomal breakage , chromosomal bridge, laggard chromosome, chromosomal stickiness and multipolar division, but the highest number of chromosomal breakage was observed, the second micronucleus. Micronucleus frequency increased with the increase of Cr6＋ concentration and the prolong of treatment duration when the Cr6＋ mass concentration≤100 mg/L, however, micronueleus frequency decreased at 200 mg/L Cr6＋for 48 h.

关 键 词：铬胁迫 根尖细胞 蚕豆 有丝分裂 染色体异常 

分 类 号：X173[环境科学与工程—环境科学]