Prenner Gerhard, Cardoso Domingos
Royal Botanic Gardens, Kew, Jodrell Laboratory, Richmond, Surrey TW9 3DS, UK
National Institute of Science and Technology in Interdisciplinary and Transdisciplinary Studies in Ecology and Evolution (INCT IN-TREE), Instituto de Biologia, Universidade Federal da Bahia, Rua Barão de Jeremoabo, s/n, Ondina, 40170-115, Salvador, Bahia, Brazil.
Ann Bot. 2017 Feb;119(3):417-432. doi: 10.1093/aob/mcw223. Epub 2016 Dec 26.
The study of floral morphology and ontogeny and the re-investigation of existing data help to uncover potential synapomorphic characters and foster our understanding of phylogenetic relationships that rely primarily on molecular analyses. Goniorrhachis marginata is a monotypic caesalpinioid legume (Leguminosae) that shows some interesting floral features, such as a long hypanthium and regular Rosaceae-like flowers. We studied the ontogeny and morphology of the flowers in detail and present our results in a broad phylogenetic context.
Flower buds were collected in the field, fixed in 70 % ethanol and investigated using scanning electron microscopy. Older buds in spirit were carefully opened to investigate the direction of style bending. Characters of the style from 131 taxa from the main legume lineages were analysed and mapped on a Bayesian molecular phylogeny.
The tetramerous calyx is the result of complete loss of one sepal. The formation of the radially symmetrical corolla starts in a typical caesalpinioid pattern with the adaxial petal innermost (ascending aestivation). The young style bends in the abaxial direction, which is a character found exclusively in all studied detarioid legumes and therefore a newly described synapomorphy for the clade.
We show that investigation of unstudied taxa and reinvestigation of published data can uncover new, previously overlooked and important characters. Curvature of the style can be detected in young buds with a hand lens and therefore is an important character for field botanists. Our study reveals the importance of including poorly studied and/or phylogenetically enigmatic taxa in molecular phylogenies and in detailed morphological and ontogenetic analyses.
对花的形态学和个体发育进行研究以及对现有数据进行重新调查，有助于发现潜在的共衍征性状，并增进我们对主要依赖分子分析的系统发育关系的理解。边缘镰瓣豆是一种单型的云实亚科豆科植物，具有一些有趣的花部特征，例如长花托和类似蔷薇科的整齐花。我们详细研究了花的个体发育和形态，并在广泛的系统发育背景下展示了我们的研究结果。
在野外采集花芽，固定于70%乙醇中，并用扫描电子显微镜进行观察。小心打开浸泡在酒精中的较老花芽，以研究花柱弯曲的方向。分析了主要豆科谱系中131个分类群的花柱特征，并将其映射到贝叶斯分子系统发育树上。
四基数花萼是一片萼片完全缺失的结果。辐射对称花冠的形成始于典型的云实亚科模式，即近轴花瓣位于最内侧（上升式花被卷叠式）。幼嫩花柱向远轴方向弯曲，这是所有研究的云实亚科豆科植物中独有的特征，因此是该分支新描述的共衍征。
我们表明，对未研究的分类群进行调查以及对已发表数据进行重新调查，可以发现新的、以前被忽视的重要特征。用手持放大镜可以在幼嫩花芽中检测到花柱的弯曲，因此这是野外植物学家的一个重要特征。我们的研究揭示了在分子系统发育以及详细的形态学和个体发育分析中纳入研究不足和/或系统发育关系不明的分类群的重要性。
