Normand Frédéric, Bello Abdoul Kowir Pambo, Trottier Catherine, Lauri Pierre-Eric
CIRAD, UPR HortSys, Station de Bassin-Plat, BP 180, 97455 Saint-Pierre Cedex, Reunion Island, France.
Ann Bot. 2009 Jun;103(8):1325-36. doi: 10.1093/aob/mcp079. Epub 2009 Apr 5.
Growth and reproductive strategies of plants are often related to particular, although usually poorly characterized, spatial distributions of shoots within the plant's architecture. In this study it is therefore hypothesized that a close relationship exists between architectural position, axis morphology (length, diameter, leaf area), and functional behaviour (branching, flowering and fruiting). The study focused on the architectural position of mango growth units, defined here as being the relative position, apical or lateral, on the parent growth unit, i.e. growing from the apical or a lateral meristem, respectively.
Stem length and leaf characteristics (area, dry weight) were measured on apical and lateral growth units of four mango cultivars over two years. Branching, flowering and fruiting were assessed for both growth unit types using an exhaustive description of tree vegetative and reproductive growth over two years. The relationships between growth unit diameter and flowering and fruiting were assessed for one of the four cultivars.
A pronounced morphological dimorphism was observed for the four cultivars. Across cultivars, stem length was significantly 1.31-1.34 times longer and total leaf area was 2.54-3.47 times larger in apical compared to lateral growth units. Apical growth units tended to branch, flower and fruit more than lateral growth units. The relationship between growth unit diameter and flowering rate was quadratic and dependent on growth unit position. The relationship between growth unit diameter and fruiting rate was linear and independent of growth unit position.
Morphological traits of mango growth units were clearly involved in the determinism of flowering and fruiting, although in different ways. The results, however, showed that current hypotheses of flowering, such as carbohydrate availability and florigenic promoters, are not sufficient in themselves if they neglect the hierarchical relationships between axes, i.e. their relative position, apical or lateral.
植物的生长和繁殖策略通常与植物结构内枝条特定的空间分布相关，尽管这些分布通常特征描述不足。因此，本研究假设在结构位置、轴形态（长度、直径、叶面积）和功能行为（分枝、开花和结果）之间存在密切关系。本研究聚焦于芒果生长单元的结构位置，这里将其定义为在母生长单元上的相对位置，即顶端或侧生，分别从顶端分生组织或侧生分生组织生长而来。
在两年时间里，对四个芒果品种的顶端和侧生生长单元测量了茎长和叶特征（面积、干重）。通过对两年内树木营养生长和生殖生长的详尽描述，评估了两种生长单元类型的分枝、开花和结果情况。对四个品种之一评估了生长单元直径与开花和结果之间的关系。
观察到四个品种存在明显的形态二态性。在各品种中，顶端生长单元的茎长显著比侧生生长单元长1.31 - 1.34倍，总叶面积大2.54 - 3.47倍。顶端生长单元比侧生生长单元更倾向于分枝、开花和结果。生长单元直径与开花率之间的关系是二次曲线关系，且取决于生长单元位置。生长单元直径与结果率之间的关系是线性的，且与生长单元位置无关。
芒果生长单元的形态特征明显以不同方式参与了开花和结果的决定过程。然而，结果表明，如果当前关于开花的假设，如碳水化合物可用性和成花素启动子，忽略了轴之间的层级关系，即它们的相对位置（顶端或侧生），那么这些假设本身是不充分的。
