Comparative study on vegetal and physiological characteristics of different salt-tolerant plants under salt stress

To study the salt-tolerant mechanism of different salt-tolerant plants, the growth of young shoots, the number of new roots and some physiological indexes, such as Na+, K+ content, the Na+ / K+ ratio, proline, chlorophyll content, the photosynthetic rate, stomatal conductance and the transpiration rate of three species, Raphiolepis umbellata, Morus alba and Rosa chinensis were determined. Comparative study show that when the concentration of solution increases and the stress time prolongs, the impacts of salt-stress increase; the main osmotica of Raphiolepis umbellata under salt-stress is inorganicion, while the main osmotica of Morus alba and Rosa chinensis is praline; when the concentration increases, physiological indexes, including chlorophyll content, the photosynthetic rate, stomatal conductance and the transpiration rate increase at first and then decrease, and the range of change in order is Rosa chinensis, Morus alba and Raphiolepis umbellata. It can be concluded that the capability of salt-tolerance of Raphiolepis umbellata is the largest, and then are the capabilities of salt-tolerance of Morus alba and Rosa chinensis .