Cultivated alfalfa was selected from a complex taxonomic group called the Medicago sativa-falcata complex. The complex includes a number of diploid (2n = 2x = 16) and tetraploid (2n = 4x = 32) taxa. Prior information of ploidy is vital for the effective utilisation of genetic resources in alfalfa breeding programs. | M. ŞAKİROĞLU, E. C. BRUMMER Research Article Turk J Bot 35 (2011) 509-519 © TÜBİTAK doi: Clarifying the ploidy of some accessions in the USDA alfalfa germplasm collection Muhammet ŞAKİROĞLU1,*, Edward Charles BRUMMER2 1 Kafkas University, Faculty of Art and Sciences, Department of Biology, 36100 Kars - TURKEY 2 The Samuel Roberts Noble Foundation, Forage Improvement Division, Ardmore, OK 73401 - USA Received: Accepted: Abstract: Cultivated alfalfa was selected from a complex taxonomic group called the Medicago sativa-falcata complex. The complex includes a number of diploid (2n = 2x = 16) and tetraploid (2n = 4x = 32) taxa. Prior information of ploidy is vital for the effective utilisation of genetic resources in alfalfa breeding programs. From the US National Plant Germplasm System, we obtained the seeds of 256 wild accessions thought to be from the 3 diploid subspecies included in the M. sativa-falcata complex, in order to determine their ploidy level using flow cytometry: M. sativa subsp. caerulea, M. sativa subsp. falcata, and M. sativa subsp. hemicycla. A majority of the accessions classified as subsp. hemicycla were found to be either tetraploid (27 out of 32) or a mixture of diploid and tetraploid (2 out of 32), suggesting that they ought to be reclassified as subsp. varia. Only 3 accessions consisted of purely diploid genotypes. Out of 71 accessions classified as subsp. caerulea, 7 were found to be tetraploid and 8 accessions were admixed. Of the 153 accessions of subsp. falcata, 67 were diploid, 82 were tetraploid, and 4 accessions showed within-accession ploidy-level variation. We recommend reclassifying the tetraploid accessions to reflect the ploidy levels detected in this study. Key words: Alfalfa germplasm, ploidy, M. Sativa-falcata complex ABD Tarım Bakanlığı Bitki Genetik Kaynaklar Sistemindeki bazı yonca aksesyonlarının ploidi düzeyinin tespiti Özet: Kültürü yapılan yonca, karmaşık bir taksonomik .
