Differences in resistance to high temperature stress of 10 cold-season turfgrass varieties

To screen the suitability of cold-season turfgrass varieties for Hunan and solve their problems associated with summer in Hunan, 10 cold-season turfgrass cultivars of six species adapting well and widely naturalized in Hunan were selected as research objects, namely, Festuca arundinacea, Festuca rubra, Lolium perenne, Poa pratensis, Trifolium repens, and Agrostis stolonifera. The changes in their turf characteristics; physiological and biochemical indicators of free proline, soluble sugar, chlorophyll, and malondialdehyde content; and leaf membrane lipid permeability at 25 ℃ (CK) and three stress-related high temperatures, 30 ℃, 35 ℃, and 40 ℃ were analyzed. The results showed no obvious differences in turf characteristics and physiological and biochemical indicators between the 10 cold-season turfgrass cultivars of the six species under high-temperature stress. The soluble sugar, malondialdehyde, and proline content in the leaves and leaf electric conductivity increased with increasing temperature. The chlorophyll content decreased with increasing temperature. According to the turf characteristics expressed in the field planting experiment and the physiological and biochemical index changes under high-temperature stress of the different cold-season turfgrass cultivars, their high-temperature resistance was concluded to be in the following order: Festuca arundinacea ‘Vegas’ > Festuca arundinacea ‘Barrera’ > Festuca rubra ‘Bridgeport II’ > Festuca arundinacea ‘Ikay’ > Trifolium repens ‘Koala’ > Poa pratensis ‘Barrister’ > Lolium perenne ‘Bartwingo’ > Lolium perenne ‘Accent’ > Poa pratensis ‘Wellow’ > Agrostis stolonifera ‘Regent’.