Abstract:

In order to select salt-tolerant soybean germplasm as the foundation for salt-tolerance breeding, 52 soybean genotypes were exposed to 0.4% of NaCl and 0.8% of NaCl, and the germination indices and some seedling stage indices were investigated for salt tolerance. The results showed that the germination potential, germination rate, hypocotyl length and diameter of the population were decreased significantly under 0.8% of NaCl treatment, compared with the control and 0.4% of NaCl treatment, but there were significant differences among individuals in the population. Salt-intolerant soybean germplasm had significantly lower chlorophyll content and leaf relative water content under 0.4% and 0.8% of NaCl stress than salt-tolerant soybean germplasm. The ability of holding Na⁺ in the roots in salt-intolerant germplasm was decreased under 0.8% of NaCl stress, while Na⁺ contents in the stems were higher than that of salt-tolerant germplasm. A total of 18 salt-tolerant soybean germplasm materials, 23 intermediate soybean germplasm materials and 11 salt-intolerant soybean germplasm materials were screened by membership function method.

Key words: soybean, salt resistance, germplasm resources, germination period, membership function method