Effects of Mulching with Hyperaccumulator Straw on Photosynthetic Pigment Contents in Grape Seedlings under Cadmium Stress

To study the effects of mulching with straw of different cadmium hyperaccumulators (Crassocephalum crepidioides, Galinsoga parviflora, Youngia japonica and Gnaphalium affine) on photosynthetic pigment contents in grape seedlings was conducted by a pot experiment under cadmium stress. The results showed that mulching with straw of C. crepidioides and G. parviflora increased the content of chlorophyll a and total chlorophyll of grape seedlings. All the straw-mulch treatments increased the chlorophyll b content of grape seedlings, and the chlorophyll a/b for all the treatments had no significant difference. Except mulching with Y. japonica reduced the content of carotenoid, other straw-mulch treatments increased the carotenoid content of grape seedlings. Especially, mulching with G. parviflora significantly increased the content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid, with a increasing of 40.60%, 47.85%, 42.80% and 47.79%, respectively. In conclusion, mulching with G. parviflora straw could increase photosynthetic pigment contents of grape seedlings under cadmium stress.