Evaluation On Salt Tolerance Of Lines In Peanut RIL Population During Seedling Germination Stage

Peanut is an important oil and economic crop in China.Planting salt-tolerant varieties is of great significance to make full use of saline-alkali land,to develop peanut production,to ensure the safety of oill supply in China.In this study,using sand culture method,the suitable salt concentration was determined to identify peanut salt tolerance in the seedlings,according to seedling emergence rate and plant biomass under different salt stress conditions.The salt tolerance of the RIL population constructed from the cross of Baisha 1016(P1)and ICGV86699(P2)were determined.The extreme salt-tolerant lines and salt-sensitive lines were selected for the determination of physiological traits.The main results are as follows:1.Under the conditions of Sand culture method,Pre-test was conducted with 0,0.2,0.4,0.6,0.8and 1.0% NaCl concentrations with Shanhua 9.The seed germination rate was 11.7%and seedling emergence rate was 0,when the NaCl concentration was more than 0.6%.On this basis,11 peanut varieties(lines)selected as materials,14 related salt-tolerance traits,seed germination rate,emergence rate,main stem height,hypocotyl length,main root length,plant fresh weight,removing cotyledon plant fresh weight,stem and leaf fresh weight,hypocotyl fresh weight,root fresh weight and stem and leaf dry weight,hypocotyl dry weight,cotyledon dry weight,root dry weight,were measured,under the treatment of 0,0.1,0.2,0.3,0.4,0.5%NaCl concentrations.The relative values of the traits were calculated using the treatment with NaCl concentration of 0 as a control.The results showed that at 0.3% NaCl concentration,the relative emergence rates of 11 peanut materials and other related salt-tolerance traits were significantly different.Therefore,it was determined that the salt concentration suitable for identification of the NaCl concentration was 0.3%.2.The salt-tolerance of 188 lines of RIL population was identified at 0.3% NaCl concentration.Based on the relative values of 14 related to salt-tolerance traits,such as seed germination rate and seedling emergence rate of each line,the membership function was used to calculate the salt tolerance of the lines.The 188 lines of RIL population were clustered byD values and divided into five salt tolerance types.Among them,9 lines were highly salt-tolerant,14 lines were salt-tolerant,118 lines were moderately salt-tolerant,and 37 lines were salt-sensitive,12 lines were highly sensitive,parents P1 and P2 are moderately salt-tolerant.3.The coefficient of variation of 14 related to salt-tolerance traits in the RIL population ranged from 4.22% to 21.43%.The distribution of relative values of main stem height,main root length,the plant fresh weight,removing cotyledon plant fresh weight and cotyledon dry weight were the normal distribution,and were quantitative traits and could be used for analysi of QTLs related to salt tolerance and development of molecular markers.4.Using 12 salt-tolerant lines,8 salt-sensitive lines and their parents as materials,SOD,POD activity and MDA content of leaves at 14 days after sowing were determined.The results showed that there was a very significant positive correlation between D value and the relative value of SOD activity and the relative value of POD activity,and there was a significantly negative correlation between D value and the relative value of MDA content.5.The technical specification for salt tolerance identification of peanut at seedling germination stage,using sand culture method,was established.