Recurrent production of plants of black plum, Syzygium cuminii (L.) Skeels, a myrtaceous fruit tree, from in vitro cultured seedling explants

The epicotyl segments bearing scaly leave(s), excised from in vitro grown seedlings of Syzygium cuminii, produced multiple shoots when cultivated on Murashige and Skoog's (MS, 1962) medium supplemented with different concentrations of BA (0-2 mg l ). The optimum response was recorded on the medium containing 1 mg l BA. An average of 8.6 shoots per explant were produced 60 days after inoculation, following transfer to fresh medium after 30 days. The shoots were excised, and the residual explants were transferred to fresh medium, where they again developed shoots. Up to five such passages resulted in the production of shoots from the repeatedly subcultured original explants. However, during the fifth passage, organogenic response was negligible and the explants turned brown thereafter. Following repeated harvesting of shoots and subculture of the residual explants, an average of 29 shoots per explant was obtained. The in vitro developed shoots produced roots when transferred to Knop's medium supplemented with 2% sucrose and 1 mg l IAA. The developed plantlets were planted in soil and transferred to fields after an acclimatization period of 7-8 months. These plants have been thriving well for more than 3 years. The nodal explants excised from in vitro developed shoots and plants also exhibited a similar response when cultured on MS+1 mg l BA. Thus, a protocol has been developed to raise plants of S. cuminii at any time of the year.