GENETIC-VARIABILITY FOR MORPHOLOGY, GROWTH AND FORAGE YIELD AMONG PERENNIAL DIPLOID AND TETRAPLOID LUCERNE POPULATIONS (MEDICAGO-SATIVA L)

The wide diversity within the Medicago sativa complex is well known, b ut comparative data on different populations representing the sub-spec ies sativa and falcata are lacking. Morphological and agronomic charac ters of 25 populations or varieties of lucerne belonging to the M sati va complex were studied at Lusignan (France) in 1993 and 1994. The lan draces and varieties of the sub-species sativa were clearly different from the wild populations of the 2 sub-species sativa and falcata by t heir erect growth habit, their fast regrowth after cutting, the absenc e of rhizomatous plants, their tall height and their high forage yield . Within the cultivated populations, those originating from northern F rance had a higher winter resistance than the Mediterranean population s, and higher yields. The winter resistance trait and the variegated f lowers of the French sativa landraces show that they have integrated s ome traits belonging to sub-species falcata. The group of wild populat ions contained diploid and tetraploid populations, and sativa or falca ta populations. Among the characters analysed, only flower colour made the distinction possible between the wild sativa populations from Spa in (Mielga) with purple flowers and the falcata populations with yello w flowers. This convergence of forms between the 2 sub-species could b e a strategy of tolerance to animal feeding and to treading.