Registration of Kura1 Trifolium ambiguum (M. Bieb) Germplasm

Kura1 is a broad-based autohexaploid (2n = 6x = 48) Trifolium ambiguum (M. Bieb) germplasm (Reg. No. GP-280; PI 643168) selected for aggressive rhizomatous spreading ability and plant vigor in a southern Wisconsin environment. Kura1 was developed jointly by the University of Wisconsin-Madison and the U.S. Dairy Forage Research Center (USDA-ARS), Madison, WI, and released jointly by the USDA-ARS and the University of Wisconsin Agricultural Experiment Station in December 2006. Few improved kura clover breeding populations exist in North America with even fewer named varieties. Kura1 germplasm is a very competitive addition to the improved germplasm base available to breeders. Kura1 was developed by selecting 69 parents for persistence, vigor, and spreading ability out of a common space plant nursery of 35 kura clover plant introductions, breeding populations, germplasm, or varieties. Syn1 seed was produced in Wisconsin in 2004 and Syn2 seed was produced in Wisconsin in 2008. In southern Wisconsin, Kura1 has 12% higher forage yield and 100% better spreading than 'Cossack' and 29% higher forage yield and 33% better spreading than 'Rhizo'. Kura1 also has extensive additive variance for important traits of seedling establishment and vigor, general plant vigor, rhizomatous spreading ability, and seed yield.