关键词: 高羊茅, 盐胁迫, 离子含量, 光合特性, 抗氧化酶活性

Abstract: To compare the salt tolerance of two tall fescue cultivars ('Titanium 2LS' and 'Easycare'),we treated the two cultivars with 500 mmol·L^-1 NaCl for 14 days and measured the morphological indexes,ion content,photosynthetic parameters to further compare the tolerance of the two species of tall fescue seedlings to salt stress. The results showed that the above-ground biomass and below-ground biomass of both tall fescue species were significantly reduced under salt stress (P<0.05),but the below-ground biomass of 'Titanium 2LS' was reduced less than that of 'Easycare';the K⁺/Na⁺ of both tall fescue species decreased significantly (P<0.05) under 500 mM salt stress,but the change of 'Easycare' was more significant;the soluble sugar and proline contents in two tall fescue seedlings increased. In addition,photosynthetic parameters and fluorescence parameters of the two species decreased significantly,and SOD activity decreased significantly,but the decrease of 'Titanium 2LS' was smaller than that of 'Easycare';POD activity did not change significantly between the two species of tall fescue,but the POD activity of 'Titanium 2LS' showed an increasing trend and that of 'Easycare' showed a decreasing trend. In conclusion,under salt stress,'Titanium 2LS' could maintain relatively high K⁺/Na⁺ and better photosynthetic capacity,accumulate more proline and soluble sugar to alleviate the injury,and alleviate osmotic stress,ionic toxicity,and oxidative stress induced by salt stress,thus it is more advantageous to the plant growth. Therefore,the salt tolerance of 'Titanium 2LS' is better than that of 'Easycare'.

Key words: Tall fescue, Salt stress, Ion content, Photosynthetic characteristics, Antioxidase activity