Ballard, H. E. , Wahlert, Gregory A. , de Paula-Souza, Juliana , Feng, Min .
Molecular phylogenetic relationships, intrafamilial groups, and a proposed classification for the Violet family (Violaceae).
Recent comprehensive sampling of all accepted genera and many species in the largest genera for the trnL intron, trnL-F spacer and rbcL chloroplast regions provided us the opportunity to confidently reevaluate relationships among previously recognized genera and the current intrafamilial classification of the Violet family (Violaceae). The trnL/L-F and rbcL data sets are mostly congruent and differ only in relative placement of Allexis, Mayanaea and Rinoreocarpus. Both data sets and the combined analysis place Fusispermum basal to the rest of the family, the bulk of Rinorea above it (with two species falling among hybanthoid groups higher up in the tree), and other Violaceae in a grade of smaller clades. More basal clades have chromosome numbers based putatively on x=6, whereas more derived groups are based on x=8. The so-called genus Hybanthus is extensively polyphyetic as our previous studies showed, presently represented by nine morphologically, cytogenetically and phylogenetically distinct clades worthy of generic segregation. The current classification, with subfamily Fusispermoideae (Fusispermum), subfamily Leonioideae (Leonia), and subfamily Violoideae with the rest of the family assigned to several tribes based mostly on floral symmetry and presence/absence of staminal nectaries with spurs, is almost wholly unsupported; floral zygomorphy and nectary evolution are clearly highly homoplastic. The genus Leonia generally forms a clade with another Neotropical indehiscent-fruited genus, Gloeospermum. Hybanthus s. str., Orthion and Mayanaea form a well supported clade distinguished by unusual long-pedunculate compound cymes and large smooth white seeds. West African Allexis, Noisettia, Schweiggeria and the largest genus, Viola, form a heterogeneous clade. The lianescent genera Agatea, Anchietea and Corynostylis form a highly supported clade with herbaceous climber Hybanthopsis, all with flattened seeds. Most of Latin American Hybanthus groups with Hawaiian Isodendrion in a large and highly supported clade with distinctive androecial morphology. A preliminary new classification is proposed.
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1 - Ohio University, Dept. of Environmental & Plant Biology, and Molecular & Cellular Biology Program, 317 Porter Hall, Athens, Ohio, 45701, USA
2 - Ohio University, Department of Environmental & Plant Biology, Porter Hall, Richland Avenue, Athens, Ohio, 45701-2979, USA
3 - Universidade de São Paulo, Instituto de Biociências, Rua do Matão, trav. 14, nº 321, Cidade Universitária, São Paulo, 05508, Brazil
4 - Chinese Academy of Sciences, Institute of Botany, State Key Laboratory of Systematic and Evolutionary Botany, Haidian District, 20 Nanxincun, Xiangshan, Beijing, 100093, China
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Maybird/Cliff Lodge - Level C
Date: Wednesday, July 29th, 2009
Time: 11:00 AM