Effects of Salt Stress and Temperature on Seed Germination and Seedling Growth of Morus alba

Seeds from 16-year-old Morus alba trees were used to investigate the effects of NaCl concentrations and germination temperatures on seed germination, seedling growth and root development. Results showed that the germination percentage, germination index, vigor index, seedling biomass, root biomass, root/shoot ratio, root length and root surface area decreased with the increase of salt concentration, mean germination time and root diameter increased. With the increase of temperature, G and GI increased, MGT decreased, but SB, RB, R/S, RL and RSA increased first and then decreased, and reached the maximum at 30 ℃. NaCl concentration and temperature had significant interaction on MGT, RB and R/S, and the appropriate increase of temperature alleviated the salt stress of the above indexes. SB was significantly positive correlated with RB, R/S, RL and RSA, and root growth was a sensitive index to reflect the stress of seedlings.