Abstract:

To improve the saline-alkali soil in eastern Hebei, we selected the heavy saline-alkali soil and sandy loam soil in Huanghua of eastern Cangzhou in Hebei Province to mix in different proportions, and explored the growth and physiological characteristics of salt-tolerant and salt-sensitive alfalfa under salt stress. The results showed that different proportions of saline-alkali soil could inhibit the growth of alfalfa. When saline-alkali soil: sandy loam soil was no more than 1:2, the plant height, aboveground biomass, the number of main branches and lateral branches, underground biomass and root length of ‘Zhongmu 3’ had no significant difference; when the proportion was less than 1:2, salt stress could promote the growth of ‘Zhongmu 3’; but when saline-alkali soil: sandy loam soil exceeded 1:2, salt stress had a significant inhibition effect on the growth of ‘Zhongmu No.3’. The salt-sensitive variety ‘WL440HQ’ showed that with the proportion of saline-alkali soil increased, the plant height, above-ground biomass, underground biomass, number of main branches and lateral branches and root length decreased significantly. Salt stress increased the content of proline and malondialdehyde in the leaves of alfalfa. The proline and malondialdehyde content of ‘Zhongmu 3’ increased in the seedling stage to early flowering stage under the treatment of YJ-2 (saline-alkali soil: sandy loam soil = 1:2), indicating that the variety had the strongest adaptability in saline-alkali soil: sandy loam soil=1:2. In the heavy saline-alkali land in eastern Cangzhou, the mixing ratio of saline-alkali soil: sandy loam soil = 1:2 will not affect the normal growth of salt-tolerant alfalfa variety ‘Zhongmu 3’, and can improve the use of local saline-alkali soil.

Key words: salt stress, alfalfa, physiological traits, growth traits, influence