Effects of Plant Growth Regulators on Papayas (Carica Papaya) Cultured in vitro

Abstract

Micropropagation of papaya variety “Khag Dum” and “Solo” was obtained by culturing papaya shoot apices and buds on modified MS medium containing 0.5 mg/1 BA and 0.2 mg/1 NAA. The increasing rate of multiple shoots was about 7 folds of plants during subculturing periods. The papaya plantlets approximately 2-3 cm. in height could be rooted on MS medium with 1.5 mg/1 IBA. After subculturing these shoots onto the same medium more than one years, the vitrification of shoots and plantlets was observed. Futher multiplication and rooting of vitrified papaya shoots and plantlets was unsuccessful. Therefore, interchangeable of the media containing white 0-5 mg/1 kinetin, 15% coconut water, and 0-0.2 mg/1 NAA were substituted for subculturing. Papaya plantlets were best geown on MS medium containing 15% coconut water, 0.1 mg/1 NAA, and 120 mg/1 adenine sulfate. About 80% of these plantlets were successfully rooted on MS medium with 1.5 mg/1 IBA.