Alces and Zebu, two new, tetraploid cultivars of Italian ryegrass

Tetraploid Italian ryegrass Lolium multiflorum ssp. italicum is distinguished by a high yield potential and a good forage quality. Here, we present two new, tetraploid cultivars of Italian ryegrass bred by Agroscope FAL Reckenholz, the Swiss Federal Research Station for Agroecology and Agriculture. The cultivar Alces was derived from our diploid cultivar Axis by colchicine treatment. It is distinguished by superior yields in the first main production year and by an outstanding resistance against crown rust. When the cultivar Zebu was developed, special consideration was given to frost tolerance by screening under artificial conditions. Zebu remains fully productive until the end of the second main production year and its high yields are well equilibrated throughout the growing season. Both new cultivars are clearly better digestible than the diploid cultivar Oryx. The high content of digestible organic matter of Alces and Zebu has not been hampered by the increase in yield as compared to previously cultivated Swiss cultivars of tetraploid Italian ryegrass, like Lipurus, Vicugna and Ellire.