Cialdella Ana M, Salariato Diego L, Aagesen Lone, Giussani Liliana M, Zuloaga Fernando O, Morrone Osvaldo
Instituto de Botánica Darwinion, Labardén 200, San Isidro, B1642HYD Buenos Aires, Argentina.
Cladistics. 2010 Dec;26(6):563-578. doi: 10.1111/j.1096-0031.2010.00310.x.
© The Willi Hennig Society 2010. ABSTRACT: The tribe Stipeae, with nearly 550 species, includes 28 core genera, of which 13 occur in America: Achnatherum, Aciachne, Amelichloa, Anatherostipa, Hesperostipa, Jarava, Nassella, Ortachne, Oryzopsis, Pappostipa, Piptatherum, Piptochaetium and Ptilagrostis. Based on 37 species representing 14 Stipeae genera, and using four chloroplast markers and morphological characters, we provide a phylogenetic hypothesis of the New World Stipeae, with our focus on Amelichloa and Aciachne. Parsimony analyses included two approaches: (i) a multiple-sequence alignment where gaps were treated as missing or coded, (ii) using direct sequences by direct optimization as implemented by the program POY v.4.0.2870. Analyses under direct optimization were conducted using the molecular data sets independently and combined, and with morphological data. Different cost regimes were explored and the one producing the highest congruence between partitions was chosen. Among the genera considered, only Piptochaetium, Austrostipa, and Hesperostipa were resolved as monophyletic, while Achnatherum, Amelichloa s.l., Anatherostipa, Jarava and Nassella were polyphyletic, and Aciachne was polyphyletic or paraphyletic. As a result, Amelichloa can be restricted to a monophyletic group if including A. brachychaeta, A. ambigua, A. clandestina and A. caudata, or it should be considered within Nassella. The phylogenetic position of species of Aciachne suggests inbreeding and outbreeding events with species of Anatherostipa, Ortachne and Hesperostipa.
© 威利·亨尼希协会2010年。摘要：针茅族包含近550个物种，有28个核心属，其中13个分布于美洲：芨芨草属、无芒针茅属、沙鞭草属、异针茅属、西针茅属、加拉针茅属、纳氏针茅属、奥塔针茅属、落芒草属、拟针茅属、扁穗草属、细柄草属和冠毛草属。基于代表针茅族14个属的37个物种，并利用四个叶绿体标记和形态特征，我们提出了新大陆针茅族的系统发育假说，重点关注沙鞭草属和无芒针茅属。简约分析包括两种方法：（i）一种多序列比对，其中空位被视为缺失或编码，（ii）使用程序POY v.4.0.2870实现的直接优化直接序列。直接优化分析分别使用分子数据集独立进行、合并进行以及与形态数据一起进行。探索了不同的代价体系，并选择了在各分区之间产生最高一致性的体系。在所考虑的属中，只有细柄草属、澳针茅属和西针茅属被解析为单系类群，而芨芨草属、广义沙鞭草属、异针茅属、加拉针茅属和纳氏针茅属是多系类群，无芒针茅属是多系类群或并系类群。因此，如果将短颖芨芨草、歧颖芨芨草、隐匿芨芨草和尾稃芨芨草包括在内，沙鞭草属可以限定为一个单系类群，或者应将其视为纳氏针茅属内的类群。无芒针茅属物种的系统发育位置表明其与异针茅属、奥塔针茅属和西针茅属物种存在近交和远交事件。
