Regional Diversity in Nondormant Alfalfas from India and the Middle East

Alfalfa (Medicago sativa L.) is an important crop in many desert regions with long growing seasons. Very non-winterdormant (nondormant) cultivars are derived primarily from germplasm obtained from low elevations in the Middle East and India. Improved understanding of diversity in alfalfas from these regions may enhance conservation and utilization of this germplasm resource. To better characterize patterns of diversity in very nondormant Indian and Middle Eastern alfalfas, we evaluated 34 accessions from low elevations in western, central, and northern India, and throughout the Middle East in a field trial in Tucson, AZ, during 1989 to 1992. Middle Eastern accessions included representatives of geographical groups formulated in previous research. Cluster analysis and plots of the first three principal components of 12 agronomic and six morphological traits were used to describe patterns of variation among accessions. Both analytical approaches showed that Indian accessions were phenotypically distinct from the Middle Eastern germplasm evaluated. Northern Indian germplasm was much more persistent and higher yielding than that from western India and was generally more similar to the majority of Middle Eastern accessions than to accessions from western India. Most accessions from the Gujarat state in western India were exceptional, exhibiting very poor persistence and adaptation to temperatures near 0 °C. Arabian accessions were generally distinctive, especially those from western and southern Arabia which exhibited very rapid regrowth following harvest. Results of this study and previous research suggest that at least six regional germplasm groups exist among nondormant North African, Arabian, and Indian alfalfa germplasm. Support provided by the Arizona Agric. Exp. Stn.