Collection of Trifolium sp and other forage legumes in Bulgaria

Joint collecting expeditions to improve the genetic diversity of Trifolium species in the U.S. National Plant Germplasm System (NPGS) were carried out in Bulgaria by scientists of the USDA-ARS, University of Florida, Texas A& M University, and Institute of Introduction and Plant Genetic Resources (II PGR), Bulgaria, on 14-27 July 1990 and 30 July - 13 August 1993. The object ives were to collect seed of T. vesiculosum Savi and other annual clovers i n southeastern Bulgaria in 1990 and seed of perennial Trifolium species in southwestern Bulgaria in 1993. A total of 246 collections were made of 50 T rifolium species (38 annual and 12 perennial) and 25 collections of 17 othe r forage legumes. Collections were made at 90 sites in 13 of the 20 florist ic regions in Bulgaria. The genetic diversity of T. vesiculosum in the NPGS was increased by the addition of 16 accessions. Four Trifolium sp. were ad ded to the NPGS. Land utilization for intensive grazing near villages and s mall plot farming in river valleys greatly increased between 1990 and 1993. Genetic erosion of the extensive Trifolium resources within Bulgaria may o ccur as these practices increase.