TITLE:
Stimulation of Multiple Leader Formation in Some Genotypes of Acacia mangium and Acacia auriculiformis with 6-Benzylaminopurine (BAP)
AUTHORS:
Ahmed Mohamed Adam Eldoma, Sures Kumar Muniandi, Nor Aini Ab Shukor
KEYWORDS:
Cytokinin, Multiple Leader, Provenance, Genotypes, Apical Control, Stem Form
JOURNAL NAME:
Open Journal of Forestry,
Vol.5 No.7,
September
21,
2015
ABSTRACT: Acacia mangium Willd. and Acacia auriculiformis A. Cunn. ex. Benth. are two of the
fast-growing tropical acacias which have received priority for genetic
assessment and improvement. They were therefore proposed for timber production
in a short rotation in Malaysia but were impeded by the multiple leaders (ML)
formation which limited their value as sawn timber. This work attempts to investigate
the causes of ML formation in four genotypes of A. mangium and A. auriculiformis as related to apical dominance, nutrition and plant growth hormones and their correlations.
The effects of 6-benzylaminopurine and decapitation on ML formation of these
genotypes were also investigated. 6-benzylaminopurine (BAP) as a foliar spray
and also decapitation did not stimulate ML formation. However, they
significantly increased the number of branches and reduced all other growth
traits including height. However, basal diameter was not affected by
decapitation. The effects of BAP increased consistently with increasing level
of application. BAP at 1500 mg·Lǃ resulted in mortality of A. mangium provenances while A. auriculiformis provenances survived
and grew normally. Some of the BAP treated plants of both species developed
juvenile pinnate leaves. Decapitation of the apical bud resulted in the
activation of the lateral bud immediately below the point of decapitation.