镉胁迫下多穗柯幼苗的生长及生理响应

Responses of Growth and Physiology of Lithocarpus polystachyus Rehd Seedlings under Cadmium Stress

分别用0(对照)、50、100、150、200和250 mg/L的镉处理多穗柯(Lithocarpus polystachyus Rehd)幼苗,研究镉胁迫环境对其生长、生理和光合特性的影响。结果表明:50 mg/L处理的多穗柯幼苗株高和地茎的增长量以及整株的干重均比对照显著性提高;100、150和200 mg/L处理的幼苗各生长指标均有所降低但差异不显著,但相对电导率和渗透调节物质、CAT和POD活性均显著性增高;250 mg/L处理时,幼苗的生物量、形态指标显著性降低,而相对电导率和渗透调节物质显著性增大。说明50 mg/L镉浓度处理有利于多穗柯幼苗的生长,250 mg/L处理则幼苗的生长、生理和光合作用受到显著性抑制。

T he effects of cadmium stress on the growth, physiology and photosynthetic characteristics of Lithocarpus polystachyus Rehd were studied by using 0 （control） , 50, 100, 150, 200 and 250 mg/L of cadmium. The results showed that the plant height increment, stem increment, and dry weight of 50 mg/L treatment were significantly higher than that of CK. The growth indices of 100, 150 and 200 mg/L treatments were all decreased, but the difference was not significant. However, the relative electrical conductivity and osmotic adjustment substances, CAT and POD activity were significantly increased. Under the 250 mg/L cadmium treatment, the biomass, morphological indexes and photosynthetic parameters of the seedlings were significantly decreased, while the relative electrical conductivity and osmotic adjustment substances were increased significantly. The results indicated that 50 mg/L cadmium concentration was beneficial to the growth of the seedlings, and the growth, physiology and photosynthesis of the seedlings were significantly inhibited by the 250 mg/L treatment.