Induced resistance in alfalfa against rust disease by gamma rays

A programe was carried out that aims at inducing new source of rust disease resistance in alfalfa.Dry seeds of local cultivar were treated with 0,50,100 and 150 Krads of gamma rays at a dose rate of 45.0 red/sec.The radiosensitivity of alfalfa was significantly affected by gamma doses.Resistant plants were selected during series of artificial inoculations of M2 and M3 progenies.Data of screening procedure indicated that repeating the inoculation was very necessary to confirmhighly plants.All resistant plants selected after the fourth in oculation improred their resistance at the last inoculation.In the field,all selected plants remained highly resistant to the disease and most of them showed considerable increment in number of tillers and the fresh weight.(3 tabs., 15 refs.)