不同土壤硒水平对白术幼苗生长及部分生理特性的影响

lthough Se has not been considered an essential element for higher plants, numerous studies have shown that selenium (Se) plays an important role in promoting plant growth. Therefore, it is of great significance to learn the effects of different soil Se levels on the growth of Atractylodes macrocephala and physiological mechanism underlying plant response to exogenous selenium. In this study, a pot experiment was conducted to explore the comprehensive effects of different Se treatments (0, 5, 10, 25, 50, 100 milligram Se per kilogram air-dry soil) on growth of A. macrocephala seedlings. The results were as follows: 5 mgg-1 Se treatment increased the fresh weight, leaf SPAD (soil and plant analyzer development) value and leaf soluble sugar (SS) content of A. macrocephala seedlings by 8.8%, 8.4% and 60.3%, respectively; While decreased the leaf soluble protein (SP) and malondialdehyde (MDA) content by 32.1% and 18.9% respectively, as well as depressed the activities of peroxidase (POD) and catalase(CAT), compared with the control. Treatments of Se >25 mgg-1 were not beneficial to the growth of A. macrocephala seedlings, resulting in a significant increase in MDA and superoxide anion radical (2-) content, which destroyed the antioxidant system. Principal component analysis showed that fresh weight, plant height, leaf SP content and activities of CAT and POD could be used as characteristic indexes to reflect the growth status of A. macrocephala seedlings. In conclusion, the appropriate soil Se levels could significantly promote the growth of A. macrocephala seedlings, and 5 mgg-1 soil Se level was the optimum. Application of appropriate Se to the soil could be beneficial for efficient breeding and industrial production of A. macrocephala.