关键词: 钙, 盐胁迫, 光合作用, 水稻

Abstract: Two rice (Oryza sativa L.) cultivars, Wuyujing No.3 (salt-tolerant) and IR36 (salt-sensitive), were used to investigate the effects of exogenous calcium on some photosynthetic and physiological characteristics of the leaves of rice grown under salt stress. The results showed that the photosynthesis and photosynthetic efficiency of the leaves of salt-stressed rice were significantly enhanced with the inclusion of Ca2+. The levels of net photosynthetic rate and stomatal conductance increased more significantly than the control without Ca2+, and the rate of increase or decrease of intercellular CO2 concentration and stomatal limitation value were faster than that of the control without Ca2+ too. Addition of Ca2+ increased the contents of chlorophyll, proline and soluble sugar of the leaves of rice under salt stress. Furthermore, addition of Ca2+ reduced the content of MDA and the permeability of cell membrane, but increased the SOD activity.

Key words: Calcium, Salt stress, Photosynthesis, Rice