Tuesday, November 6, 2007
169-10
UV-B Tolerance of Cool-Season Turfgrass Species and Cultivars.
Xunzhong Zhang and Erik H. Ervin. CSES Department, Virginia Tech, Blacksburg, VA 24061-0404
Ultraviolet-B radiation is a major factor causing quality decline of newly transplanted sod. Selection and use of turfgrass species and cultivars with improved tolerance to UV-B is a practical approach for increased sod transplanting success. This study investigated the relative UV-B tolerance of 7 cultivars of Kentucky bluegrass, 5 of tall fescue, 3 of Chewing’s fescue, and 3 of perennial ryegrass under artificial UV-B stress. Eight-week old grass seedlings were subjected to UV-B treatment for 10 days and permitted to recover for 15 days. Turfgrass quality, photochemical efficiency, and cell membrane leakage measurements indicated that Kentucky bluegrass cultivars were the least UV tolerant, while Chewing’s fescues had the most tolerance. Within species ‘Ebony’ and ‘Montana ’ tall fescues had the best UV-tolerance, while ‘Bluetastic’, Blueriffic’, and ‘0747’ Kentucky bluegrasses were superior. Differences in superoxide dismutase activity was also observed between cultivars. The data suggests that species and cultivar UV-B tolerance was associated with improved photochemical efficiency and cell membrane integrity.