Morphological and Agronomic Affinities among Middle Eastern Alfalfas—Accessions from Oman and Yemen

Alfalfa ( Medicago sativa L.) is a common element of oasis agriculture in the Middle East; however, germplasm from this region has not been widely used in alfalfa breeding elsewhere. Previous research in Arizona showed that ecotypes from the southern portion of the Arabian Peninsula possess traits that may be useful in breeding very nondormant cultivars. The objectives of this research were to describe morphological and agronomic variation among 41 accessions from Oman, Yemen and southwestern Saudi Arabia, and eight accessions representing basic germplasm groups from elsewhere in the Arabian Peninsula and North Africa. Results of this research will be useful in preservation and utilization of these germplasm resources. Data collected from a 2‐yr field trial at Tucson, AZ, were evaluated by average linkage cluster and principal components analyses. Southern Arabian accessious collected below elevations of 1000 m were distinct from those collected at higher elevations. The most distinctive accessions were from low‐elevation oases in Yemen and were extremely susceptible to frost damage. Accessions from the Salalah Coastal Plain in Oman were especially variable, perhaps reflecting recent importation. Based largely on poor response to low winter temperatures, accessions from low elevations in Yemen were shown to be separable from those from Oman. Germplasm from the Batinah Coastal Plain and the Hajar Foothills in Oman could not generally be separated. The Saudi Arabian ecotype Hasawi was similar to germplasm from northern Oman. Utilization of affalfa germplasm from subtropical environments in southern Arabia may be complicated outside this region by its adaptation to intensive management under frost‐free conditions.