K. DHINESH BABU, S. SATHIAMOORTHY, N. CHEZHIYAN AND KAPIL DEO N SINGH
Abstract
A protocol was standardized during 1996-97 to eliminate the bacterial and fungal contamination that occurs during the in vitro clonal propagation of papaya (Carica papaya L.). The axillary buds of papaya genotype 9-1 D were used as ex pla nt to initiate the culture. Gentamycin, an effective antibiotic against the bacteria was used for spraying the mother trees (source plants) before excision of explants, soaking the excised explants and for spraying the mother trees followed by axillary bud soaking. Among the various concentrations of gentamycin ( 0,125,250,375 tinci 500 mg1-'), the bacterial contamination was minimum (38.75%) when gentamycin @ 500 mg1-1 was used for both spraying mother trees and soaking axillary buds for thirty minutes prior to inoculation. Similarly to reduce the fungal contamination, fungicide Carbendazim 50% wp 0.1 per cent was used for spraying mother trees and soaking the axillary buds prior to inoculation. Among the various spray schedules attempted on alternate days (0, 1, 2, 3 and 4 sprays), the fungal contamination was minimum (45.63%) when mother trees of papaya were sprayed 4 times and axillary buds were soaked for thirty minutes in 0.1 per cent solution of Carbendazim 50% wp prior to inoculation in Murashige and Skoog medium fortified with Benzyl Amino Purine @ 1.0 mgl.