Effects Of Salt Stress On Physiological Characteristics And Yield Of Different Rice Varieties

Soil salinization has seriously hindered the development of agriculture,and planting rice to improve saline soil is a very simple and effective way of biological improvement.Due to the distribution of saline-alkali soils,the current researches on rice salt tolerance mostly use japonica rice varieties,while there are few studies on indica rice varieties.Therefore,the varieties selected in this experiment are mainly indica hybrid rice varieties.Aiming at the coastal salt-alkali land in Jiangsu where Na Cl is the main hazard,an indoor experiment was designed to simulate the effect of salt stress on rice bud and seedling stage,and combined with field experiments to explore the effect of salt stress on different rice varieties.The main1.For the bud stage test,10 japonica rice varieties and 33 indica rice varieties were compared,and Na Cl solutions at four concentrations of 0,0.2%,0.4%,and 0.6% were used to simulate salt stress.The results showed that under the same salt concentration treatment,the salt tolerance performance of different varieties was different;with the increase of salt concentration,the root bud length,root number,germination vigor,germination rate and fresh dry weight of root buds of different varieties showed a downward trend.The electrical conductivity of the buds showed an upward trend.Through comprehensive evaluation,two indica varieties(R2803 and YW01)with strong salt tolerance at the bud stage and 6 varieties with strong salt tolerance were selected.Among them,3 conventional japonica rice(Huaidao)No.5,Yangjing 3491 and Koshihikari),2 conventional indica rice(Huang Huazhan and R889),and 1 indica hybrid rice(Yexiang A/Haipin 12).2.In the seedling stage test,23 indica hybrid rice varieties were selected.After the bud stage test was completed,the seedlings with the same growth were selected,and the corresponding salt concentration treatment was applied to the bud stage test to continue the cultivation.Studies have found that salt stress will reduce the survival of rice seedlings.As the salt concentration increases,the survival rate will gradually decrease,and the rate of dead leaves will gradually increase.It will also affect various protective enzymes(SOD,POD and CAT)and malondialdehyde(MDA).)Has an impact,and the difference between species and salt concentration is extremely significant;the SOD activity of most species will be inhibited,while the activities of POD and CAT will be increased;the number of protective enzymes that play a role is different between different species.Finally,through the average relative salt damage rate of the two salt concentration treatments,5 varieties with strong salt tolerance were screened out(C815S/Zhong 08,Coconut A/Hai Pin 12,C815S/9 Hai 28,C815S/9 Hai 69 And C815S/9 Hai 55),6 varieties with strong salt tolerance(1146S/R2803,Tian A/Hai Pin 12,Shennong A/Hai Pin 12,416S/9 Hai 55,416S/9 Hai 28 and C815S/9 Hai30).3.Field experiments selected 24 hybrid indica rice varieties,and dynamically measured changes in the absorption of sodium and potassium ions and changes in dry matter weight in plants,as well as changes in sodium and potassium ions in the soil and changes in soluble salts.The results showed that rice planting significantly reduced the content of sodium and potassium ions and total soluble salt in the soil.The content of sodium and potassium was reduced by 5.51% and 28.18%,and the content of soluble total salt was reduced by 33.42%,and the accumulation of sodium and potassium by the plants 3 salt-tolerant hybrid indica rice varieties(Family 20A/R2259,416S/9 Hai 28 and C815S/9 Hai 30)were screened out.4.Based on the 23 hybrid indica rice varieties used in the three experiments,the salt tolerance of different rice varieties is different,and the salt tolerance is different at different growth periods.The comprehensive average relative salt damage rate at the bud and seedling stage and the field sodium The comprehensive comparison of potassium ion absorption and yield found that the salt tolerance of varieties 416S/9 Hai 28 and C815S/9 Hai 30 performed better throughout the growth period,and it was found that the sodium ion accumulation of these two varieties was higher than that of other varieties.Much higher.