弯囊苔草对Pb^(2+)胁迫的响应及其Pb富集能力  

Responses of Carex dispalata to Pb^(2+) Stress and its Accumulation Ability

作　　者：程龙玲[1] 周守标[1] 吴晓艳[1] 王欣[1] 常琳琳[1] 

机构地区：[1]安徽师范大学生命科学学院,安徽重要生物资源保护与利用研究重点实验室,安徽芜湖241000

出　　处：《水土保持学报》2012年第4期216-220,共5页Journal of Soil and Water Conservation

基　　金：安徽省高校自然科学基金项目(2006kj060a;KJ2011A129);安徽省自然科学基金项目(11040606M77)

摘　　要：通过水培实验研究不同Pb2+浓度(0,250,500,1 000,1 500,2 000μmol/L)下和不同时间(1,5,9,13,17d)Pb2+对弯囊苔草生长、生理指标及富集能力的影响。结果表明:(1)株高、最长根长、新增根数、新分蘖数、鲜重和地上与地下部分的干重比均随着Pb2+浓度增大明显下降。(2)3种抗氧化酶活性均随着胁迫时间延长呈现先上升后下降的趋势。随着Pb2+胁迫浓度增加,CAT和POD活性显著升高,SOD活性呈现先上升后下降的趋势。(3)MDA含量、Pro含量和质膜透性均随着Pb2+处理浓度的增加和胁迫时间延长而显著增加。(4)叶绿素含量在胁迫初期时明显增加,胁迫时间长时含量显著下降。(5)弯囊苔草体内Pb含量随Pb2+浓度增大而增加,根系对Pb的富集能力明显高于地上部分。根系对Pb的平均滞留率为84.62%,弯囊苔草对Pb的转移系数小于1。因此,研究表明弯囊苔草对Pb胁迫有一定的耐受性和适应性。The response of growth characteristics, physiological indices and the Pb accumulation ability in Carex dispalata under Pb2＋ stress were researched by water culture method. Different concentrations of Pb2＋ were added to C. dispalata and measured physiochemical characteristics on the 1, 5, 9, 13, 17 d respec- tively. The results showed. （1）Plant height, length of longest root, new root, new tillers, fresh weight and the ratio of shoot to root dry weight were declined drastically with increasing Pb level. （2） Activities of antioxidant enzymes increased in the beginning and then decreased with extended time of exposure. With increasing Pb2＋ stress concentrations, activity of CAT and POD were significantly increased~ while activity of SOD increased in the beginning and then decreased. （3）MDA, Pro content and plasolemma permeability were significantly increased with increasing Pb concentrations and the prolongation of stress time. （4）Chlorophyll content was obviously increased in primary phase of Pb stress, but reduced gradually under longer stress time. （5）Pb content in C. dispalata was increased with the rising of Pb2＋ concentrations and it withstands excess Pb with its higher Pb accumulation capacity in roots compared to the above-ground part. Pb average retention rate in root of C. dispalata was 84.62 % and the biological transfer coefficient to Pb was less than one. The study indicated that C. dispalata could adapt and resist a certain extent of Pb toxicity.

关 键 词：弯囊苔草 Pb2+胁迫 生理特性 Pb富集能力 

分 类 号：Q945.78[生物学—植物学]