Physiological Responses Of Wild Soybean In Hadong Wetland To Salt Stress And Screening Of Salt-tolerant Germplasm

Soil salinization is a difficult problem restricting agricultural production,and even affects China's food security.Based on the importance of soybean production and the serious impact of soil salinization,improving salt tolerance has become an important topic of soybean breeding.In this paper,wild soybean seeds in Hadong riverside wetland were used as materials to screen salt tolerant germplasm,and treated with Na Cl solution.The growth characteristics,chlorophyll content,malondialdehyde proline content,chlorophyll fluorescence characteristics and light response curve of wild soybean and cultivated soybean under salt stress were compared,and the salt tolerance of wild soybean was verified and analyzed.It is expected to provide experimental material basis for the establishment and improvement of cultivated soybean salt tolerant Germplasm in our province,and provide theoretical reference for the development and utilization of wetland salinized areas in the cold region of Northeast China.The results showed that among the 10 wild soybeans,LY-10-25 wild soybeans showed better salt tolerance than other materials after salt stress treatment;Under the same concentration of salt stress,the decline of the underground part of the two kinds of soybean was slightly higher than that of the aboveground part;The decline of photosynthetic parameters and biomass accumulation of cultivated soybean under salt stress was greater than that of wild soybean;The root shoot ratio of wild soybean decreased more than that of cultivated soybean under salt stress;The actual photochemical efficiency,electron transport rate and photochemical quenching coefficient of cultivated soybean and wild soybean decreased with the increase of salt stress concentration and light intensity,and the decline range of soybean indexes in different concentration salt stress treatment groups increased under high intensity light;The non photochemical quenching coefficient of wild soybean increased significantly,and the difference between the two kinds of soybean was more significant under strong light.Research shows:(1)Among the 10 tested materials,wild soybean LY-10-25 has strong salt tolerance.(2)Under salt stress,the inhibition of the underground part of the two kinds of soybean was slightly higher than that of the aboveground part.The reason may be that the root system,as the organ most directly exposed to salt stress,is more affected by salt stress.(3)Salt stress prompted soybean to change its biomass distribution pattern.Compared with cultivated soybean Dongnong 48,wild soybean LY-10-25 retained a greater proportion of aboveground supply under salt stress.(4)Light intensity intensified the inhibition of Soybean under salt stress,and there was a synergistic effect between light and salt stress.The photosynthetic reaction center of wild soybean LY-10-25 has a stronger ability to convert excess light energy into heat than cultivated soybean Dongnong 48.Under strong light conditions,the advantage of heat dissipation ability of wild soybean LY-10-25 is more obvious.