Institut für Spezielle Botanik und Botanischer Garten, Johannes-Gutenberg Universität Mainz, Germany.
Ann Bot. 2013 Nov;112(8):1523-42. doi: 10.1093/aob/mct009. Epub 2013 Feb 27.
Conceptual and terminological conflicts in inflorescence morphology indicate a lack of understanding of the phenotypic diversity of inflorescences. In this study, an ontogeny-based inflorescence concept is presented considering different meristem types and developmental pathways. By going back to the ontogenetic origin, diversity is reduced to a limited number of types and terms.
Species from 105 genera in 52 angiosperm families are investigated to identify their specific reproductive meristems and developmental pathways. Based on these studies, long-term experience with inflorescences and literature research, a conceptual framework for the understanding of inflorescences is presented.
Ontogeny reveals that reproductive systems traditionally called inflorescences fall into three groups, i.e. 'flowering shoot systems' (FSS), 'inflorescences' sensu stricto and 'floral units' (FUs). Our concept is, first, based on the identification of reproductive meristem position and developmental potential. The FSS, defined as a seasonal growth unit, is used as a reference framework. As the FSS is a leafy shoot system bearing reproductive units, foliage and flowering sequence play an important role. Second, the identification of two different flower-producing meristems is essential. While 'inflorescence meristems' (IMs) share acropetal primordia production with vegetative meristems, 'floral unit meristems' (FUMs) resemble flower meristems in being indeterminate. IMs produce the basic inflorescence types, i.e. compound and simple racemes, panicles and botryoids. FUMs give rise to dense, often flower-like units (e.g. heads). They occur solitarily at the FSS or occupy flower positions in inflorescences, rendering the latter thyrses in the case of cymose branching.
The ontogenetic concept differs from all existing inflorescence concepts in being based on meristems and developmental processes. It includes clear terms and allows homology statements. Transitional forms are an explicit part of the concept, illustrating the ontogenetic potential for character transformation in evolution.
花序形态学中的概念和术语冲突表明人们对花序的表型多样性缺乏理解。在这项研究中，我们提出了一个基于个体发生的花序概念，该概念考虑了不同的分生组织类型和发育途径。通过追溯个体发生的起源，可以将多样性简化为有限数量的类型和术语。
研究了来自 52 个被子植物科的 105 个属的物种，以确定其特定的生殖分生组织和发育途径。基于这些研究、长期的花序经验和文献研究，提出了一个理解花序的概念框架。
个体发生揭示，传统上称为花序的生殖系统分为三组，即“开花枝系统”（FSS）、“花序”（inflorescences）和“花单位”（FUs）。我们的概念首先基于生殖分生组织位置和发育潜力的识别。FSS 被定义为季节性生长单位，用作参考框架。由于 FSS 是一个带有生殖单位的叶状枝系统，因此叶序和开花顺序起着重要作用。其次，识别两种不同的产生花的分生组织至关重要。虽然“花序分生组织”（IMs）与营养分生组织共享向顶式原基的产生，但“花单位分生组织”（FUMs）在不定性方面类似于花分生组织。IMs 产生基本的花序类型，即复合和简单的总状花序、圆锥花序和聚伞花序。FUMs 产生密集的、通常如花的单位（例如头状花序）。它们在 FSS 上单独出现，或者在花序中占据花的位置，使得后者在聚伞状分枝的情况下成为伞形花序。
该个体发生概念与所有现有的花序概念不同，它基于分生组织和发育过程。它包括清晰的术语，并允许同源性陈述。过渡形式是该概念的一个明确部分，说明了进化中特征转化的个体发生潜力。
