Comparison On Physiological Effects Of Salt Stress On Seedlings Of Glycine Max, Glycine Soja And Their Hybrid

Soil salinization has become one of the important environmental problems affecting the ecosystem and the sustainable development of agriculture. In this study, the Glycine max Lee68cultivar that internationally recognized as the salt-tolerant, the Glycine soja N23227population and their hybrid3060(F5) strain selected for salt tolerance generation by generation were used as the experimental materials. And the physiological effects of the3materials under salt stress were comparative analyzed. The results show that:The salt tolerance of the hybrid3060has relatively improved compared to its female parent Lee68, between its parents; the salt tolerance of the Glycine soja N23227population was the strongest; the salt tolerance of the Glycine max Lee68cultivar was the relatively weakest. Using140mmol·L-1NaCl solution to treat the above seedlings for6d, the plant relative growth rate, water content, and the osmotic potential of the3experimental materials were declined. The value of R/T, MDA content, and relative electrolytic leakage were increased. The changes in most of above physiological indexes of3060were between its parents.Under salt stressed, leaf areas of the3materials were decreased when compared with the control, and Lee68were decreased most. The chlorophyll and carotenoid contents in leaves, net photosynthetic rate and Fv/Fm were declined with the increase of salt stress time, and net photosynthetic rate and Fv/Fm of Lee68were declined most. Under salt stress, the DPPH·radical scavenging activities in roots of the3materials were remarkably ascended when compared with the control; and in leaves3060and N23227were remarkably ascended.Under salt stress, the contents of Na+, Cl-in roots, stems, leaves and chloroplasts were increased with the increase of salt stress time, while the contents of K+and K+/Na+were declined. And the changes in ion contents of3060were between its parents. The fluorescence intensity of Cl-in protoplasts of roots and leaves of the3materials seedlings were declined with the increase of salt stress time. Reduce in Cl-fluorescence intensity can reflect the concentration of Cl-. So we can get the sequence of the concentration of Cl-in protoplasts of roots:N23227>3060> Lee68; and the sequence of the concentration of Cl-in protoplasts of leaves:Lee68>3060> N23227.In summary, through the cross between Glycine max Lee68cultivar and Glycine soja N23227population, and selection generation by generation, the salt tolerance of their hybrid3060strain was obviously improved compared to its female parent.