Cr^6＋对高丹草幼苗生理特性与根尖细胞有丝分裂的影响

采用室内培养的方法，研究了不同浓度（0、0．5、1．0、1．8mmol·L^-1）K2CrO4处理高丹草幼苗后对其生长、相关生理特性及细胞分裂的影响。结果表明，随着Cr^6＋处理浓度增加，高丹草幼苗生长受到抑制，质膜透性、丙二醛（MDA）含量持续升高；叶片中可溶性糖、脯氨酸（Pro）含量呈现升高趋势，1．0mmol·L^-1处理下增加幅度最为显著；可溶性蛋白和叶绿素含量逐渐降低。此外，不同浓度（0、50、100、150mmol·L^-1）Cr^6＋处理影响高丹草幼苗根尖分生区细胞有丝分裂，统计分析结果显示：有丝分裂指数、染色体畸变率、微核率与处理浓度间有很好的线性关系，处理浓度与有丝分裂指数显著负相关（P〈0．05），与染色体畸变率、微核率呈显著正相关（P〈0．05）。高丹草幼苗生长生理变化规律、根尖有丝分裂指数、染色体畸变率及微核率可以作为监测环境中Cr^6＋含量的参考指标。

Effects of Cr^6＋ on Physiological Characteristics and Mitosis of Root Tip in the Seedlings of Sorghum Hybrid Sudangrass

The aim of this study was to investigate the effects of different concentrations of Cr^6＋（0,0.5,1.0, 1.8 mmol·L^-1 K2CrO4）on the growth ,physiological characteristics and mitosis of Sorghum Hybrid Sudangrass. Different concentrations of Cr^6＋ induced a significant reduction of root length, root volume and dry weight except 0.5 mmol·L^-1 Cr^6＋ treatment.The increasing concentration of Cr^6＋ caused a continuous rise of plasma membrane permeability and malondialdehyde （MDA）content, but resulted in a gradual reduction of chlorophyll content and soluble protein content in leaves.However, soluble sugar content and proline（Pro）content followed a pattern of first rise then decline, and documented the summit value under 1.0 mmol·L^-1 Cr^6＋ treatment in leaves. Moreover, different concentrations of Cr^6＋（0, 50, 100, 150 mmol·L^-1 K2CrO4）induced nuclear aberrance on root tip cells of Sorghum Hybrid Sudangrass. Furthermore, a significantly negative correlation between mitotic index and Cr^6＋ concentration, and a positive correlation between chromosomal aberration index, micronucleus index and Cr^6＋ concentration were also obtained（P〈0.05 ）. Hence, we suggest that the physiological index,characteristics mitotic index, chromosomal aberration index and micronucleus index can be avaliable for monitoring environmental Cr^6＋ in contaminated areas.