EFFECT OF EXPLANTS AND GAMMA IRRADIATION ON CALLUS INDUCTION OF THREE SOYBEAN GENOTYPES ( GLYCINE MAX L. ) IN VITRO

Abstract

An experiment was conducted in order to examine the sensitivity of callus culture for three soybean genotypes namely Taka 1, Taka 2 and Lee74 to gamma rays. Shoot apex, Cotyledonary leaves and Stems segments were taken from seedlings and cultured in MS medium supplemented with plant growth regulators for callus induction incubated in growth room at 25±2°C and 16 hrs photoperiod with light intensity of 1000 Lux. After that callus exposed to different doses of gamma rays 0,5,10,15,20,30,40 Gray was incubated at the same conditions. Results showed Cotyledonary and stem segments significant superior in fresh, dry weight than shoot apex, Also Lee74 superior in these characters reached 1176.13 mg, 417.66 mg respectively, than Taka 1 and Taka2. Results revealed gradual reductions in fresh, dry weight of callus as with the increased of gamma doses. The reduction percent were 80.11, 94.57% at 40 Gray respectively as compared with control treatment,While the dose 5 Gy increased the fresh weight reached 3.08%. However, the genotype Lee 74 was commonly significant superior than others in fresh, dry weight reach 719.48mg and 319.62 mg respectively