Givnish T J, Evans T M, Pires J C, Sytsma K J
Department of Botany, University of Wisconsin, Madison, Wisconsin 53706, USA.
Mol Phylogenet Evol. 1999 Aug;12(3):360-85. doi: 10.1006/mpev.1999.0601.
Phylogenetic relationships of the five families of the order Commelinales remain an area of deep uncertainty in higher-level monocot systematics, despite intensive morphological and anatomical study. To test the monophyly of the Commelinales and the subclass Commelinidae, evaluate their relationships, and analyze evolutionary trends in their morphology, ecology, and biogeography, we conducted parsimony analyses on 95 rbcL sequences representing 17 taxa of Commelinales, 16 taxa of other Commelinidae, and 63 taxa from Arecidae, Liliidae, and Zingiberidae. Commelinales is polyphyletic and Commelinidae paraphyletic, with Eriocaulaceae and Xyridaceae sister to Poaceae and its relatives, Rapateaceae sister to Bromeliaceae and Mayacaceae, and Commelinaceae sister to Philydrales and allies. Thurnia is sister to Prionium at the base of Cyperaceae-Juncaceae; only 1 of Cronquist's multifamily commelinoid orders is diagnosed as monophyletic. We propose a revised Commelinidae, incorporating 4 revised superorders (Bromelianae, Commelinanae, Dasypogonanae, Arecanae) and 10 orders ((Poales, Eriocaulales, Cyperales, Typhales, Bromeliales), (Commelinales, Philydrales, Zingiberales), (Dasypogonales), (Arecales)). Morphological and anatomical characters used to define the original Commelinales and Commelinidae appear to be plesiomorphic or to reflect convergence or recurrent mutation; several characters supporting our revised classification are anatomical traits that seem relatively insulated from environmental selection pressures. The Commelinidae distal to the Arecales arose in South America, with amphiatlantic Bromeliaceae-Mayacaceae-Rapateaceae originating in the Guayana Shield. Ecological diversification involved the repeated invasion of shady, infertile, or arid microsites. The numbers of species in families of the revised Commelinidae are related partly to the extent of adaptive radiation in those families, but seem more strongly related to nonadaptive features promoting speciation, such as restricted seed dispersal (especially in forest interior groups with fleshy fruits), polyploidy, aneuploidy, and apomixis. Species diversity is unrelated to the rate/amount of rbcL sequence evolution.
尽管进行了深入的形态学和解剖学研究，但在高级单子叶植物系统学中，鸭跖草目五个科的系统发育关系仍然是一个存在很大不确定性的领域。为了检验鸭跖草目的单系性和鸭跖草亚纲的单系性，评估它们之间的关系，并分析它们在形态学、生态学和生物地理学方面的进化趋势，我们对95个rbcL序列进行了简约分析，这些序列代表了鸭跖草目的17个分类单元、其他鸭跖草亚纲的16个分类单元以及来自槟榔亚纲、百合亚纲和姜亚纲的63个分类单元。鸭跖草目是多系的，鸭跖草亚纲是并系的，谷精草科和黄眼草科是禾本科及其近缘类群的姐妹群，帚灯草科是凤梨科和雨久花科的姐妹群，鸭跖草科是田葱科及其近缘类群的姐妹群。刺鳞草属是莎草科-灯心草科基部的普里翁草属的姐妹群；克朗奎斯特的多科鸭跖草类目中只有1个被诊断为单系的。我们提出了一个修订后的鸭跖草亚纲，包括4个修订后的超目（凤梨超目、鸭跖草超目、刺叶树超目、槟榔超目）和10个目（（禾本目、谷精草目、莎草目、香蒲目、凤梨目），（鸭跖草目、田葱目、姜目），（刺叶树目），（槟榔目））。用于定义原始鸭跖草目和鸭跖草亚纲的形态学和解剖学特征似乎是近祖的，或者反映了趋同或反复突变；支持我们修订分类的几个特征是解剖学特征，似乎相对不受环境选择压力的影响。槟榔目远端的鸭跖草亚纲起源于南美洲，泛大西洋的凤梨科-雨久花科-帚灯草科起源于圭亚那地盾。生态多样化涉及对阴暗、贫瘠或干旱微生境的反复入侵。修订后的鸭跖草亚纲各科的物种数量部分与这些科的适应性辐射程度有关，但似乎更强烈地与促进物种形成的非适应性特征有关，如种子传播受限（特别是在有肉质果实的森林内部类群中）、多倍体、非整倍体和无融合生殖。物种多样性与rbcL序列进化的速率/数量无关。
