P.L. Glocke’s research while affiliated with The University of Adelaide and other places

The induction and anatomy of adventitious root formation were investigated in stem cuttings of six genotypes of Acacia baileyana treated with 0, 1,000 and 5,000 ppm indole butyric acid (IBA) in spring and autumn. Eight weeks after strike there was a highly significant effect of IBA on adventitious root formation, and a significant difference between genotypes in rooting ability. Rooting percentages were higher in autumn than in spring. Stem anatomy was similar in all genotypes, irrespective of rooting ability, with a sclerenchymatous fibre sheath located between the cortex and phloem. Stems treated with 5,000 ppm IBA showed statistically significant increases in ordered vascular tissue growth, cortical callus production and vascular ray development over a four week period. Adventitious root primordia were initiated in the proliferated cortical callus, and vascular connection was established via vascular rays which forced apart the sclerenchyma fibres. This often occurred in the vicinity of a leaf trace.