Alleviation Effect of Lanthanum on Cadmium Stress in Seedling Hydroponic Culture of Kidney Bean and Corn

The seedling hydroponic culture experiment of kidney bean (Phaseolus vulgaris) and corn (Zea mays) was conducted to investigate the alleviation effect of lanthanum on Cd stress. It is found that growth is seriously inhibited and metabolism is maladjusted in the two crops under 30 and 300 umol. L−1 Cd2+ stress. Plant height, taproot length, leaf area, and fresh or dry weight of root, stem, and leaf are all obviously decreased. Further, chlorophyll content decreases, membrane permeability, malonydialdehyde (MDA) content, activities of catalase (CAT) and peroxidase (POD) increases under Cd stress, as compared with the control. The damage to these two crops becomes more conspicuous with the prolongation of Cd stress. It is suggested that lanthanum might help kidney bean and corn seedlings alleviate Cd stress by improving the photosynthetic capacity, reducing membrane permeability and MDA content, and maintaining the activities of CAT and POD of these two crops.