TITLE:
Irradiance and Developmental Stages of Crown Architecture Affect Shoot Production in Rhododendron reticulatum
AUTHORS:
Kenichi Yoshimura
KEYWORDS:
Branching; Crown Architecture; Daughter Shoot; Developmental Stage; Shoot Production
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.5A,
May
30,
2013
ABSTRACT: Plasticity in
crown architecture, contributing to leaf arrangement within crown, is an important
feature for whole plant carbon assimilation and survival. In this study, I
examined the plasticity in crown architecture to light condition and developmental
stage by the changes in shoot production. Rhododendron
reticulatum expands crown with orthotropic growth in monopodial branching
in young stage, but orthotropic growth is ceased in adult stage. Main stem of
young crown is described with monopodial branching regardless of light
environment. But multi-layer crown is observed in sun-lit environment rather
than mono-layer crown in adult stage. Long shoot production for each branching system
(foliage derived from sympodial branching) in young crown is associated with
local light environment, but not in adult crown. Long shoot production rate is
correlated with long shoot production rate of its mother shoot in young crown,
but not in mono-layer crown. These results suggest that young crown expands
branches to sun-lit position whereas adult crown reduces congestion of shoots with
stochastic shoot production regardless of shoot production of mother shoots. I
concluded that both light and developmental stage are important factors for
shoot production and constructing crown architecture.