双穗雀稗对5种重金属单一胁迫的生长响应和吸收性研究

Studies on Growth and Accumulation of Paspalum Distichum Under Five Heavy Metal Single Stress

以现行土壤环境质量标准为浓度设置依据,结合实际土壤污染状况,研究了不同浓度的Cd、Pb、Cu、Zn和Cr 5种重金属单一处理对双穗雀稗生长特性的影响及双穗雀稗对其吸收性.结果表明:(1)在双穗雀稗正常生长下,Cd、Pb土壤临界值分别达到80 mg kg-1和500 mg kg-1水平以上;Cr临界值在100-120 mg kg-1之间;Zn临界值为400 mg kg-1;Cu临界值在100 mg kg-1以下.(2)双穗雀稗地上部Cd、Zn和Cr含量都随着处理浓度的增加而升高;地上部Pb和Cu含量随着处理浓度的增加先升高后降低.双穗雀稗富集系数大于1的有Cd、Cu和Zn处理,其中Cd在10mg kg-1和Zn在200 mg kg-1处理时富集系数最大,分别为1.87和2.74;Cu在200 mg kg-1处理时富集系数最大,达到7.66,此时双穗雀稗具备了超积累Cu的特征.双穗雀稗对土壤中Zn、Cu、Cd有较强的富集效率,而对Cr和Pb的富集能力较小.

Effects on growth and accumulation of Paspalum distichurn under CA, Pb, Cu, Zn and Cr single stress were studied. Concentrations of heavy metals in the soil were designed according to the State Soil Environmental Quality Standard （GB15618 -95）. The results showed that： （1） In the normal growth of Paspalurn distichurn, the soil critical value of CA and Pb reached up to 80 mg· kg-1 and 500 rag＂ kg-1 respectively , Cr was between 100- 120 mg-kg-1, Zn was 400 mgkg-1, Cu was less than 100rag kg-1. （2） With increasing CA, Zn and Cr concentration levels the content of CA, Zn and Cr in the aerial part of Paspalum distichurn rised. The content of Pb and Cu increased first and then decreased with increasing Pb and Cu concentration levels. Enrichment factors of CA, Cu and Zn were greater than 1, the maximum enrichment factors of CA and Zn were 1.87 and 2.74 respectively at Cct and Zn concentration levels of 10 mg-kg-1 and 200 mg. kg-1. The maximum enrichment factor of Cu was 7.66 at Cu concentration level of 200 mg· kg-1 Paspalum distichurn has greater enrichment efficienev of Zn. Cu and Cd in the soil.