EFFECTS OF LIGHT INTENSITY AND NUTRIENT ADDITION ON GROWTH, PHOTOSYNTHETIC PIGMENTS AND NUTRITIONAL QUALITY OF PEA SEEDLINGS

A glasshouse experiment was carried out to investigate the effects of shading and nutrient addition on growth, photosynthetic pigment content and nutritional quality of substrate-cultivated pea seedlings. The results showed that shading and nutrient addition significantly altered the growth, photosynthetic pigment, vitamin C and nitrate contents of pea seedlings. Nutrient addition improved shoot, root and total biomass significantly of pea seedling under non-shading condition, whereas nutrient addition only increased shoot biomass of pea seedling under shading condition. However, nutrient addition decreased root and total biomass of pea seedling under shading condition. Contents of chlorophyll a in stem and chlorophyll b in leaves were lowered by nutrient addition under non-shading condition, but carotenoid content in stem was improved. Additionally, contents of chlorophyll a and chlorophyll b in stem or leaves were similar under shading condition, and carotenoid content in stem was decreased under shading condition. Shading and nutrient addition markedly decreased vitamin C content in shoot of pea seedlings. Shading did not alter the nitrate content in shoot of pea seedlings, but nutrient addition increased nitrate content significantly. The results suggest that non-shading with nitrogen supply is beneficial conditions for commercial production of pea seedlings in terms of high yield, while non-shading without nitrogen supply is best for good nutritional quality. Reasonable matching of light intensity and nitrogen supply level may contribute the yield on the basis of high nutritional quality of pea seedlings.