Study On The Salt Resistance Of Two Blue Fescue Varieties

Blue fescue is an ornamental grass which the time introduced to China is not long, but developed very fast, and the scope of application is rapidly expanding. Northern China has large areas of saline-alkali soil. In order to explore the salt resistance ability and mechanism of blue fescue, in this study, a new blue fescue variety from America and a mature blue fescue variety which has applied in many northern areas were selected as test materials; this study was conducted in Baoding. Under 0%, 0.3%, 0.6%, 0.9% and 1.2% five NaCl stress levels, percentage of green leaves, plant height, diameter, relative conductivity, soluble sugar content, free proline content, SOD activity, POD activity and MDA content nine indexes was measured in 27 days.The conclusions were as follows:1. The green leaves percentage, plant height and diameter of both blue fescue cultivars decreased under NaCl stress treatment through the stress period compared with the CK treatment. Under high NaCl stress, the green leaves percentage, plant height and diameter of'Valesiaca'decreased faster.2. The relative conductivity of both blue fescue cultivars increased under NaCl stress treatment through the stress period, first slowly, later very fast. The stress level higher, the increased speed faster, and'Valesiaca'increased faster under same conditions.3. The soluble sugar content of both blue fescue cultivars nearly had same changes, but'Valesiaca'was more sensitive.4. Free proline content of two blue fescue cultivars increased to a same highest point and kept that under NaCl stress treatment. The stress level higher, the time reached the highest point shorter, and'Valesiaca'reached the highest point more quickly.5. The SOD activity was increased by NaCl treatment, with a peak occurring first, then it dropped to the initial value, at last it began to increase again. The first peak of'Valesiaca'was higher under each NaCl stress level, and'Select'reached a higher SOD at the end of experimental period.6. POD activity increased with NaCl stress in both blue fescue cultivars until a peak, the higher POD activity in 'Select' at the end and lower peak showed that it had stronger salt resistance7. The MDA content of two blue fescue cultivars both gradually increased under NaCl stress treatment, two cultivars did not have significant differences but when under 1.2% stress level, the MDA content of'Valesiaca'increased faster then'Select'. In summary, the results suggested that the decline of percentage of green leaves and changes of physiological index on two fescue cultivars with increasing NaCl stress level was obviously associated with NaCl stress levels. 'Select' was more tolerant than 'Valesiaca'during high NaCl stress level but under low NaCl stress the two behaved similar. Therefore, selection of blue fescue on the basis of these criteria may help to develop NaCl-tolerant blue fescue cultivars.