In-Vitro androgenesis in papaya (Carica papaya L.) cv. Pusa Nanha

Abstract

Papaya (Carica papaya L.) is an economically important fruit crop of tropics and subtropics. It has high nutritional value, as well as medicinal and industrial applications. Papaya is a polygamous species with three sex types male, female, and hermaphrodite. Conventional methods of papaya breeding are time consuming and needs advent of anther culture which may be effective for shortening of breeding cycles. The present study on in vitro androgenesis in papaya cv. Pusa Nanha observed the highest embryo induction rate (8.0%) when anthers werecultured on agar medium with 0.1 mg/L BA and 0.1 mg/L NAA after incubation in liquid MS medium with 2.0% sucrose for 7 days at 35ºC. The high temperature (35ºC) was more suitable for embryo induction in papaya than slightly low temperature (25ºC). At these both temperatures longer incubation of anthers in water reduced embryo induction rate. Sugar starvation results were ambiguous. Shoots were also developed in the media when used in liquid form. The highest rooting (75.0%) was observed at 2.0 mg/L IBA. Increasing IBA concentration reduced rooting. All well rooted plants were hardened in hardening chamber and successfully transferred to field. The present findings indicated that anther culture can be efficiently contributed for the direct micro-propagation of papaya plants. This study would also be helpful to the researchers to develop more efficient anther culture protocols for further improvement of papaya through in vitro androgenesis.