Karyotype and C-banding pattern of mitotic chromosomes in alfalfa, Medicago sativa L

Numerous cytogenetic studies have been performed on alfalfa (Medicago saliva L. 2n = 4x = 32), but only a few have examined the somatic chromosomes. Because the major factor limiting the study of somatic chromosomes of M. sativa is their rather uniform morphology, characterization was attempted using the C-banding technique instead of the traditional Feulgen method. Chromosome morphology and position of the heterochromatic bands resulted in satisfactory characterization of the chromosomes and provided further evidence of the autotetraploid origin of the species. It was possible to identify the homologous chromosomes and arrange them into eight groups of four. The ideogram of the basic genome of eight chromosomes was constructed. The impact of these results on cytogenetic studies and breeding research in alfalfa is discussed.