Abstract
This study evaluated the winter hardiness of 13 foreign Festulolium cultivars in Hokkaido, which is a cold region of Japan. The winter hardiness of Festulolium cultivars was compared to those of meadow fescue (Festuca pratensis Huds.) and perennial ryegrass (Lolium perenne L.) cultivars in experimental fields located in a non-frozen soil area (Sapporo) and in a frozen soil area (Nakashibetsu) in Hokkaido. The amphidipoid cultivar 'Prior' derived from the perennial ryegrass×meadow fescue hybrid showed a degree of winter hardiness as high as that of the meadow fescue cultivar 'Harusakae' which is recommended to be cultivated in a frozen soil area. The tall fescue (F. arundinacea Schreb.) introgression cultivar 'Felina' showed winter hardiness similar to that of the perennial ryegrass cultivar 'Pokoro'. Other cultivars were found to be inferior to perennial ryegrass in terms of winter hardiness. Furthermore, freezing tolerance and snow mold resistance as main factors influencing winter hardiness were also evaluated under natural and artificial conditions. The results showed that the winter hardiness of 'Prior' was more closely associated with snow mold resistance than freezing tolerance, while the winter hardiness of 'Felina' was more closely related to its freezing tolerance. A new Festulolium cultivar adapted to the severe cold region in Hokkaido would be developed using the winter-hardy materials of perennial ryegrass and meadow fescue.
