Meristem culture of Acacia mearnsii

The Black Wattle (Acacia mearnsii) is an economically important forest tree hence the need for efficient methods of amplification and clonal propagati on of superior trees. To overcome maturation effects and the number of dise ases infecting the wattle, rejuvenated tissue such as apical meristems, can be used. Meristems were taken from 30-day-old in vitro grown plants, from coppice (rejuvenated tissue) and adult material from trees of five differen t ages over two seasons. Meristems from the coppice and adult material was successfully decontaminated. Shoot production was obtained by meristems fro m in vitro grown plants, coppice and adult material, irrespective of plant age, on solidified Murashige and Skoog (MS) medium alone or supplemented wi th 2.0 mg l(-1) benzyladenine, half-strength MS and Woody Plant Medium (WPM ), under light or dark culture conditions. The age of the parent tree, from which plant material (adult or coppice plant material) was obtained, did n ot have a significant effect on the degree of shoot production. Apparently the use of coppice material was not necessary as shoot production from the meristems taken from the adult material was equal, if not greater, than tha t obtained by meristems from the coppice material. Adult trees, of differen t ages, were successfully rejuvenated through the use of meristem culture.