Effect of Hormonal Interaction on Ethylene Production for High Frequency Regeneration of Cotyledonary Explants of Bottle Gourd.

The interaction between the plant hormones throughout the plant regeneration and development is complex. In this study, we extended our investigation and showed the capacity of de novo shoot organogenesis from cotyledon explants of bottle gourd with respect to plant hormones and ethylene inhibitors. Synergistic effect of kinetin and benzyl adenine (BA) enhanced higher shoot regeneration efficiency (80.6%) than BA or kinetin alone in cotyledon explants of bottle gourd. BA and kinetin alone or their synergistic combination showed a characteristic brownish phenotype at bud formation stage related to ethylene production. The cotyledon explants cultured on MS medium supplemented with kinetin induced slightly ethylene than BA or the combination of BA and kinetin but regeneration capacity was found very poor and emergence of shoot bud delayed. BA promoted ethylene production but synergistic effect of kinetin and BA decreased ethylene production and kept a role on high frequency regeneration from cotyledon explants of bottle gourd. In this study, we also observed that polyamines and silver nitrate showed their sensitivity on the regeneration, which is hormonal dependent. The physiological relevance of the hormonal interaction with respect to regulation of ethylene action and effect on regeneration is discussed. We believe that this efficient shoot regeneration system will contribute to the production of transgenic plants as well as would be a practical tool for bottle gourd improvement.