Rejuvenation and micropropagation of adult Acacia mearnsii using coppice material

In an attempt to overcome maturation affects and loss of juvenile character istics, when using adult plant material in vitro, investigations were under taken into the the use of coppice material, as an alternative. Trees from 5 age groups (2, 4, 6, 8 and 10-years-old, respectively) of Acacia mearnsii were felled to a height of 1.5 m. After 3 weeks, coppice was noted on the s tumps of trees of all the age groups. A linear degree of coppice production was noted between the age groups, with the greatest coppice production bei ng on the 2-year-old trees and least on the 10-year-old trees. Decontaminat ion of the coppice was successful and multiple shoot production was obtaine d from all age groups on Murashige and Skoog (MS) medium supplemented with 2.0 mg l(-1) benzyladenine (BA). Various sucrose concentrations were invest igated and it was noted that greater shoot production occurred with increas ed sucrose concentrations (20 and 30 g l(-1)). It is evident that rejuvenat ion of mature tissue can be achieved through the use of coppice material. T his technique can now be used for future breeding programmes for the black wattle.