New Forests, 2012,
43 (2), p. 143-154 ISSN 0169-4286
An in vitro plant regeneration protocol via indirect organogenesis from morphogenetic callus was established for Casuarina cunninghamiana Miq. Effects of plant growth regulator NAA (naphthaleneacetic acid) and BAP (6-benzylaminopurine), sucrose and AgNO3 on callus induction, adventitious bud differentiation and shoot development were examined. Explants used were epicotyl fragments from 45-day-old seedlings. The largest callus (4.29 mm in diameter) was obtained after 1 month on a basic culture medium consisting of Murashige and Skoog A1/2 macro- and full strength micro- elements, Nitsch and Nitsch vitamins, supplemented with 0.54 mu M NAA, 3.30 mu M BAP, and 30 g L-1 sucrose. The calli were subcultured in the same medium above for 2 months. They were then cultured for another 2 months for adventitious bud differentiation and shoot development. The highest mean adventitious bud differentiation, number of shoots formed per callus and number of shoots a parts per thousand yen2 cm long per callus (47.50%, 27.38 and 4.75, respectively) were achieved on the above medium modified with NAA at 0.27 mu M and supplemented with AgNO3 1 mg L-1. Shoots were successfully rooted without plant growth regulator and the rooted plantlets survived and grew normally. This protocol for in vitro plant regeneration provides a tool not only for vegetative propagation but also for plant genetic transformation and gene function studies of C. cunninghamiana.
