铅胁迫对不同叶菜生长及铅吸收的影响

Plant Growth and Lead Uptake of Leafy Vegetables Under Lead Stress

为探明铅对不同叶菜的影响差异,通过铅污染土壤的盆栽试验,研究了21种叶菜的铅吸收差异和生物量变化。结果表明,铅胁迫对叶菜生长大部分表现抑制作用,但也有少数表现促进作用。叶菜地上部、地下部铅含量表现为随土壤铅含量的增加而显著增加(P<0.05),且地上部<地下部。不同科叶菜间地上部铅含量差异显著(P<0.05),且十字花科<菊科<伞形科;地下部铅含量差异不显著(P>0.05)。综合叶菜地上部铅含量和生物量抑制率把供试21种叶菜分为4类,矮脚80天特青菜心、碧绿粗苔菜心、竹芥菜和菠菜这4种叶菜生物量不受Pb胁迫的影响,且铅含量低,是铅轻中度污染土壤中种植安全系数较高的菜种,芫荽、黄心芹菜、白尖叶苋菜和柳叶空心菜属于高吸收铅的叶菜,花芽甜麦菜属于生长影响敏感型叶菜。

The contamination of leafy vegetables by Pb has been commonly reported in China.However,there were few experiments focused on Pb concentration difference among leafy vegetables under the same planting conditions and the selection of low-Pb cultivars.Therefore,a pot experiment was carried out to study the plant growth and Pb uptake of 21 kinds of leafy vegetables with the soil contaminated by Pb.The results indicated that Pb decreased biomass of majority vegetables with a few exceptions for the tested vegetables.Pb contents in shoots and roots increased significantly with the increasing of Pb in the soil,and Pb concentrations in roots were much higher than those in shoots.There was significantly difference in Pb content in shoots among three families,which were in the order of Brassicaceae Compositae Umbellifer-ae,but there was no significantly difference in roots between families.The vegetables were divided into four clusters based on Pb content and biomass inhibition.Teqing-80-day flowering Chinese cabbage,Bilucutai flowering Chinese cabbage,Zhu mustard and Spinach were found in high biomass and low-Pb concentration,then they should be the low-Pb leafy vegetables and suitable for moderately contaminated soils.High-Pb leafy vegetables included Coriander,Huangxin celery,Baijianye amaranth and Liuye water spinach,and Huaya sweet-lettuce was a biomass sensitive type.