镉对紫叶生菜生长及矿质元素吸收的影响

Effects of Cadmium on Growth and Mineral Nutrients Absorption of Purple Lettuce

采用水培方式,在精确控制光照及温湿度的人工气候室中进行不同浓度镉处理(0、1、2、4 mg/L)对紫叶生菜生长以及水分和矿质营养元素吸收的影响试验。水培试验以小单元的方式进行,即1个培养罐种植1株生菜。结果表明,随营养液中镉离子浓度的增加,生菜叶片发黄萎蔫现象加剧,鲜重显著降低。紫叶生菜可以在低浓度镉处理组(1 mg/L)生长,高浓度镉处理组(2、4 mg/L)紫叶生菜的生长被严重抑制;低浓度镉处理对紫叶生菜每日耗水量抑制不显著,高浓度隔处理的紫叶生菜每日耗水量显著降低;低浓度镉处理紫叶生菜对Ca、Mg吸收抑制不显著,对K的吸收基本不受影响,高浓度镉处理下植株对Ca、K、Mg的吸收显著降低;1 mg/L镉处理组营养液中64.3%的镉离子被植物体吸收,2、4 mg/L高浓度镉处理组对营养液中镉离子的吸收也较少,分别为26.5%、12.9%。

A hydroponic experiment was carried out to determine the effects of different cadmium does （0,1 mg/L, 2 mg/L, 4 mg/L） on growth, water and nutrition absorption of purple lettuce.Plants were grown in a phytotron where the light,temperature,relative humidity were controlled precisely.Each lettuce was grown in a unit pot with nutrient solution singly.The results showed that purple lettuce was sensitive to cadmium stress.As the cadmium concentration increased, there is a significant decrease in fresh weight, and the leaves are wilting.The lettuce can grow under low cadmium stress （1 mg/L）, being restrained severely under high cadmium stress （2 mg/L, 4 mg/L）.Water consumption was significant decreased under high cadmium.Under low cadmium conditions, the effects on calcium and magnesium absorption were not significant, and potassium kalium absorption is not affected.The absorption of these three mineral nutrients was significant decreased under high cadmium.In 1 mg/L cadmium stress group,64.3% cadmium was absorbed by lettuce.In 2 mg/L and 4 mg/L cadmium stress group, the absorption of cadmium was 26.5% and 12.9% respectively.