Abstract: Screening salt-tolerant yardlong bean is very important for developing salt resistant cultivars. This work was performed on 12 varieties of yardlong bean that have been cultivated across large areas in Jiangsu Province. Vermiculite was used as a cultivation matrix. During the cotyledon expansion stage, 50, 100, 150, 200, 250 mmol/L of NaCl solution was added to 1/2 Hoagland nutrient solution for treatment and the 1/2 Hoagland nutrient solution served as a control. After 4 weeks of treatment, the effects of eight indicators including salt tolerance rating(STR), chlorophyll content(SPAD), plant height(PH), root length(RL), aerial biomass fresh weight(AFW), aerial biomass dry weight(ADW), root fresh weight(RFW), and root dry weight(RDW)of yardlong beans under different concentration of salt stresses during the seedling stage were studied. The salt tolerance of 12 varieties was evaluated by membership function value(F_i), and the evaluation method of tolerance to salt in yardlong bean was determined. Based on the above method, we also assessed salt-tolerance germplasm resources in 84 representative yardlong bean accessions at the seedling stage. It was found that the STR value of 12 varieties increased with the increase of salt concentration, and the coefficient of variation was the highest under 150 mmol/L NaCl stress. Thus, we choose it as the optimum concentration for evaluating the salt tolerance of 12 yardlong bean varieties by membership function value(F_i). Suzi 41 and Lüling 4 were selected as salt-tolerant varieties(F_i>0.60), and Sujiang 1419 as salt-sensitive variety(F_i<0.30). The evaluation method of tolerance to salt was established in yardlong bean seedling stage, using the seedlings grown in vermiculite with 150 mmol/L NaCl treatment for about four weeks. There was a large variation of 84 yardlon bean germplasm accessions in F_i, 0.06-0.88, and Suzijing 1 and Zijinroudoujiao etc. as the 8 salt-tolerance accessions were selected. In this study, 10 salt-tolerant germplasm accessions screened will provide gene resources for the breeding of salt-tolerant yardlong bean.

Key words: Yardlong bean, Salt tolerance, Membership function, Germplasm

CLC Number: 

• S643.01