Tellería, M.C. , Funk, Vicki A. , Sancho, G. , Ventosa-Rodriguez, I. , Roque, N. , Kelloff, Carol L. .
Taxonomic significance of pollen features in Gochnatia and allied genera (Asteraceae, Gochnatieae).
The tribe Gochnatieae was recently established on the basis of molecular studies and is one of the basal clades of Compositae. Gochnatieae comprises the South American Gochnatia, ca. 70 species Richterago, 17 species, Cnicothamnus, 2 species, and the monotypic Cyclolepis. A key taxon of the tribe Gochnatieae is Gochnatia itself that traditionally included 6 sections. After recent molecular studies, three these sections, Discoseris, Leucomeris and Pentaphorus, were removed from Gochnatia and raised to the genus rank. Due to the high number of species of Gochnatia, molecular and morphological studies are needed. One set of characters can be obtained from pollen morphology, this study involved 130 specimens representing 47 species of Gochnatia, 10 species of Richterago, one species of Cnicothamnus, Cyclolepis, Leucomeris and Nouelia. The combination of size, shape in equatorial view, exine thickness, and the presence of conspicuous spines, small microspines or both sculptural elements in the same pollen grain allows three pollen types to be distinguished: one type is exclusive to the section Moquiniastrum, one occurs in the sections Gochnatia, Hedraiophyllum and Penthaphorus, and the final one is found in Nouelia and sect. Leucomeris. The three pollen groups described herein are in partial agreement with previous molecular and morphological studies. Nouelia and sect. Leucomeris have been closely related in recent molecular studies. Cyclolepis and sect. Moquiniastrum share pollen features and other distinctive characters as, for instance, ginodioecy. Pollen of Cnicothamnus and Richterago are close to what here we call Gochnatia core, which includes sections Gochnatia, Hedraiophyllum, and Penthaphorus. Close relationships among Cnicothamnus, Gochnatia and Richterago have been demonstrated in previous studies based in morphology and molecules. As preliminary conclusions: 1. According to the present study, pollen features of sect. Pentaphorus are not distinct from other members of the Gochnatia core; and 2. Two of the traditional Gochnatia sections, Leucomeris and Moquiniastrum appear to depart from the core of Gochnatia species.
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1 - Museo de La Plata, CONICET. Laboratorio de Sistemática y Biología Evolutiva, Paseo del Bosque s/n, FW 1900, La Plata, Argentina
2 - National Museum of Natural History, Smithsonian Institution, Department of Botany, MRC-166, P.O. Box 37012, Washington, DC, 20013-7012, USA
3 - Museo de La Plata, División Plantas vasculares, Paseo del Bosque s/n, La Plata 1900, Buenos Aires, Argentina
4 - Instituto de Ecología y Sistemática, Carretera Varona, Km 3 ½ Capdevila, Boyeros, CP 10800, AP 8029, Cuidad de la Habana, Cuba
5 - Universidad Federal de Bahía, Departamento de Botânica, Av. Ademar de Barros s.n., Ondina, 40-171.970, Salvador, Bahia, Brazil
6 - Smithsonian Institution, Dept. of Botany, MRC166, NMNH, P.O. Box 37012, 10 & Constitution Ave, NW, Washington, DC, 20013, USA
Presentation Type: Poster:Posters for Sections
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM