摘要
铺地黍(Panicum repens)因其较强的重金属等污染物净化能力和适应极端干旱−水淹能力,具有污染河岸消涨带的生态修复优势。本研究通过3种不同铅处理的盆栽试验(T_(1):水培+400 mg·L^(−1) Pb;T_(2):水培+800 mg·L^(−1) Pb;T_(3):泥土栽培+400 mg·L^(−1) Pb),研究铺地黍根、茎、叶分别在处理5、15和25 d的Pb亚细胞分布和化学形态特征,旨在探明铺地黍在不同浓度Pb胁迫和不同栽培方式下的重金属耐受机制与动态迁移转运规律。结果显示,水培条件下,铺地黍根部向地上部的迁移率随胁迫时间延长而显著增加(P<0.05);泥土栽培条件下的迁移率均显著高于水培(P<0.05)。其中,T_(1)、T_(2)和T_(3)处理下的根Pb平均含量分别为4745.85、6732.63和276.00 mg·kg^(−1),分别是叶Pb平均含量的66.20倍、80.21倍和4.30倍。铺地黍主要通过细胞壁的固定解毒Pb伤害,其次是细胞器固定,而可溶性组分含量最低,各组分之间差异显著(P<0.05)。根和茎的化学态Pb主要分布在活性较低的醋酸态和盐酸态,叶的各化学形态Pb分布趋于均衡。根Pb总量在15 d出现拐点(T_(1)和T_(3)),即5~15 d显著上升(P<0.05),而15~25 d缓慢下降(P>0.05),说明低浓度Pb胁迫下的铺地黍根吸收浓度在15 d达到极限,这可能是铺地黍在根部启动了某种逃避机制。总体上,铺地黍在纯水培条件下的根Pb富集能力显著大于泥土栽培,用于污染河岸带深水区的净化优势明显。
Torpedo grass(Panicum repens)has ecological restoration advantages in polluted water-level-fluctuation zones in rivers,lakes,and water reservoirs,due to its strong ability to purify heavy metals and other pollutants and its strong adaptability to extreme drought-flooding conditions.Through three pot experiments with different lead treatments(T_(1):hydroponic culture+400 mg·L^(−1) Pb;T_(2):hydroponic culture+800 mg·L^(−1) Pb;T_(3):soil culture+400 mg·L^(−1) Pb),the subcellular and chemical distribution characteristics of the root,stem,and leaf of torpedograss were investigated after 5,15,and 25 days of treatment,in order to reveal the heavy metal tolerance mechanism and dynamic migration and transport rules of torpedograss under different concentrations of Pb stress and different cultivation methods.The migration rate from the roots to the shoots of P.repens increases significantly with prolonged stress duration(P<0.05).The average Pb content of the roots under T_(1),T_(2),and T_(3) treatments was 4745.85,6732.63 and 276.00 mg·kg^(−1),which is 66.20,80.21 and 4.30 times the average Pb content in the leaves,respectively.Torpedograss mainly detoxifies Pb damage through the cell wall.The second most important component is the cellular state,followed by soluble components,with signi F1cant differences in the proportion of each subcellular fraction component(P<0.05).The chemical state of Pb in the root and stem were mainly distributed in the less active HAc and HCl states,respectively.The distribution ratio of Pb in the leaves of torpedograss was not obvious,and the distribution of Pb in various chemical states tended to be balanced.The accumulation of Pb(T_(1) and T_(3))in the roots of torpedograss showed an inflection point at 15 d,with a significant increase from 5 days to 15 days(P<0.05),followed by a slow decrease from 15 days to 25 days(P>0.05).This indicates that the accumulation of Pb in the roots of torpedograss reached the absorption limit at 15 days,which may be due to the activation of a certain escape mechanism in the roots of torpedograss.Overall,the root Pb accumulation ability of torpedograss under pure hydroponic conditions is significantly greater than that under soil cultivation,making it an obvious advantage for purifying polluted riverbank deepwater areas.
作者
高桂娟
韩瑞宏
王俊梅
佘婷婷
李志丹
GAO Guijuan;HAN Ruihong;WANG Junmei;SHE Tingting;LI Zhidan(Institute of Environmental Eeducation,Guangdong University of Education,Guangzhou 510303,Guangdong,China;College of Horticulture and Landscape Architecture,Zhongkai University of Agriculture and Engineering,Guangzhou 510225,Guangdong,China)
出处
《草业科学》
北大核心
2025年第2期356-370,共15页
Pratacultural Science
基金
广东省普通高校重点领域专项(2021ZDZX4004)
大学生创新创业训练计划项目(S202414278031)
广东第二师范学院生态学科研团队项目(广东二师[2020]58号)。
关键词
铅
铺地黍
亚细胞分布
化学形态
迁移率
吸收
累积
lead
torpedo grass
subcellular distribution
chemical forms
mobility rate
uptake
accumulation
作者简介
第一作者:高桂娟(1976-),女(蒙古族),内蒙古通辽人,教授,博士,研究方向为生态学。E-mail:15973617@qq.com;通信作者:李志丹(1977-),男,内蒙古锡林浩特人,高级实验师,硕士,研究方向为草学。E-mail:78336957@qq.com。
