Study on the taxonomy status of alfalfa with cream flowers

Alfalfa with cream flowers is differentiable and genetically stable; however, describing it in scientific research is difficult and ambiguous because of its taxonomical status. This research attempts to delimit the taxonomical status of 14 accessions, including Medicago sativa ssp. sativa, alfalfa with cream flowers, Medicago sativa ssp. falcata and Medicago ruthinica L., using morphology, chromosome karyotypes and inter simple sequence repeat (ISSR) markers. From morphology and the ISSR-PCR analysis, three accessions of M. ruthenica L. were clustered into an independent group, and the remaining 11 accessions were clustered into three groups apparently based on flower color. Alfalfa with cream flowers had its own remarkable chromosome karyotype. The genetic distance between alfalfa with cream flowers and M. sativa ssp. sativa was almost equal to that between M. sativa ssp. falcata and M. sativa ssp. sativa. In conclusion, alfalfa with cream flowers may be an independent population just like M. sativa ssp. falcate, representing a subspecies of M. sativa ssp. according to certain taxonomic principles.