Comparison of osmoprotectants and antioxidant enzymes of different wild Kentucky bluegrass in Shanxi province under high-temperature stress

摘要

High-temperature stress was one of the biggest threats to cool-season turfgrass, hence breeding new varieties adapted to high temperature was the fundamental way to improve the turf quality. This study was designed to determine the changes in contents of malonaldehyde (MDA), soluble sugar, soluble protein and proline, and activities of superoxide dismutase (SOD) and catalase (CAT) in different accessions of wild Kentucky bluegrass (Poa pratensis), which was collected from 13 areas of Shanxi province and subjected to 0, 5, 10, 15, 20 and 25 days of high-temperature stress, to evaluate the adaptability of different accessions of Kentucky bluegrass to high temperature stress. The results showed that the contents of soluble sugar, proline and MDA enhanced in all accessions of Kentucky bluegrass with the increase of high-temperature stress, the soluble protein contents of all accessions of Kentucky bluegrass declined under 0 to 10 days of high-temperature stress, and then increased with the increase of high-temperature stress. Inversely, the SOD and CAT activities of all Kentucky bluegrass augmented under 0 to 10 or 15 days of high-temperature stress, but they all declined with the continuous increase of high-temperature stress. The changes in osmotic and antioxidant protective system were very different in response to high-temperature stress in different accessions of Kentucky bluegrass, and the accessions of 'Qinshui' and 'Hunyuan' had the highest resistance to high-temperature stress, hence they could be used to breed new varieties that are resistant to high-temperature stress.