Effect of 2,4-epibrassinolide on seed germination and seedling growth of Medicago sativaunder salt stress

In order to figure out the mitigating effects of exogenous 2,4-epibrassinolide on seedling damage of Medicago sativa under salt stress,Medicago sativa cv.Zhongmu No.3and Longzhong treated with 150mmol/L NaCl solution were used to study the effect of EBR with different concentrations on seed germination and seedling growth.The results indicated that 1)seed germination,seedling growth and root vigor of alfalfa were restrained significantly under 150 mmol/L NaCl stress,aboveground and underground biomass were reduced as well.2)exogenous EBR mitigated the suppression effects of NaCl stress on seed germination,seedling growth and root vigor effectively,and showed an obvious concentration effect.3)under 150 mmol/L NaCl stress,10-1μmol/L EBR treatment had the best mitigating effect on alfalfa seedling,when the root vigor level in germination and seedling stage were enhanced,germination potential,germination rate,germination velocity,vigor index,sprout length,radical length and germination seedling dry weight were facilitated significantly,as well as the seedling leaf number,stem diameter,plant height,main root length,branch root number,aboveground and underground biomass.It suggested that exogenous 2,4-Epibrassinolide promoted seed germination and seedling growth of Medicago sativa under salt stress and EBR had positive impacts on inducing plant salt resistance.