香根草对重金属镉的积累及耐性研究  

Study of the Cadmium Accumulation and Tolerance of Vetiveria Zizanioides

作　　者：刘云国[1] 宋筱琛[1] 王欣[1] 闵宗义[1] 柳思勉[1] 

机构地区：[1]湖南大学环境科学与工程学院,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2010年第1期75-79,共5页Journal of Hunan University:Natural Sciences

基　　金：'十一五'国家科技支撑计划资助项目(2006BAD03A1704;2006BAD03A1706);湖南省计划项目(2009SK3029)

摘　　要：通过香根草的水溶液培养,研究了不同浓度的镉(Cd)对香根草的生理和生态的影响.结果表明:香根草富集的Cd主要被累积在根内,最高富集系数达到24.06%.溶液Cd浓度与香根草根内Cd的累积量显著正相关(r=0.987 4),与根的耐性指数呈显著负相关(r=-0.943 6).低浓度Cd(≤1 mmol.L-1)处理使根系活力和硝酸还原酶(NR)活力随时间呈现先升后降的趋势,中、高浓度Cd(≥1.5 mmol.L-1)处理使根系活力呈显著下降的趋势,且浓度越高,下降幅度越大.化学形态分析表明,在香根草体内Cd的NaCl提取态占绝对优势,在根和茎叶内的平均占52.06%和64.03%.可以认为香根草在Cd胁迫下其氮代谢、呼吸作用,植物的生长发育受到一定程度抑制,但其对Cd仍具有较强的耐性和富集能力.The physiological and ecological effects on Vetiveria zizanioides（V, zizanioides）grown in hydroponic culture under the stresses at different concentration of Cadmium（Cd）were studied. The experiment results showed that Cd mainly cumulated in the root. The highest Bioeonentration factor （BF） was 34%. of Cd with a positive correlation with Cd cumulation in the root （r=0. 987 4）, while the concentration had a negative correlation with a tolerance index of the root （r=-0. 943 6）. The root activity and nitrate reductase（NR）activity revealed an increase and then a decrease trend in low concentration treatment of Cd （41 mmol/L）with time; the root activity and nitrate reductase activity revealed an obvious descending trend in the middle and high concentration treatment of Cd （21.5 mmol/L）, and the descending extent increased with the increase of the concentration of Cd. Sequential extraction revealed that NaCl extractable-Cd was dominant in both the roots and the leaves of V. zizanioides. The average proportion was 52.06 and 64.03. V. zizanioides nitrogen metabolism, respiration and growth development were inhibited by Cd stress, but it still had a strong tolerance level and accumulation ability.

关 键 词：香根草 Cd 富集系数 根系活力 硝酸还原酶 

分 类 号：X53[环境科学与工程—环境工程]