Abstract Detail



Systematics

McGarvey, Luisa [1], Jiao, Lynn [2], Hutchison, Vera [2], Joffe, Jonah [3], Douglas, Norman [4], Ochoterena, Helga [5], Flores Olvera, Hilda [6], Moore, Michael [7].

Exploring species boundaries of Thelesperma (Asteraceae) on gypsum using molecular phylogenetics.

Gypsum is a naturally occurring mineral that exists as surface outcrops in some regions of the world and that is a relatively harsh environment for plant life. Nevertheless, such outcrops host numerous plant species that are endemic to the substrate gypsum and are adapted to the nutrient-poor conditions. Thelesperma is a genus of thirteen species in the sunflower family that often occupy gypsum in the Chihuahuan Desert region of northern Mexico and southwestern USA, although only one species is known to be restricted to gypsum. Recent fieldwork in northern Mexico has identified a group of populations that may represent a previously undescribed species of Thelesperma that appears to be restricted to gypsum. These populations are most similar morphologically to Thelesperma longipes, but they are much larger. This study aimed to test whether this is an undescribed gypsum endemic taxon and to understand the evolution of gypsophily within the genus Thelesperma. In order to test this hypothesis, the evolutionary relationships of these populations along with all other species of Thelesperma were constructed by generating DNA sequences of the nuclear ITS region and two chloroplast regions (the ndhF/rpl32 and rpl32/trnL spacer regions). DNA was extracted from a mix of herbarium and field-collected samples. Phylogenetic analysis will be used to determine whether the unusual Thelesperma populations are an evolutionarily distinct gypsum endemic species.


Related Links:
Origin and evolution of Chihuahuan Desert gypsum endemic plants


1 - Oberlin College, Department of Biology, 119 Woodland St, Oberlin, OH, 44074-1060, USA
2 - Oberlin College, Department of Biology, 119 Woodland St., Oberlin, OH, 44074-1060, USA
3 - University of Washington, Department of Statistics, Box 354322, Seattle, WA, 98195-4322, USA
4 - University Of Florida, Biology, PO Box 118525, Gainesville, FL, 32611, United States
5 - Instituto De Biología, UNAM, Botanica, Depto Botánica-Apdo.Postal 70-367, Coyoacan, Mexico DF, 04510, Mexico
6 - Instituto de Biología, UNAM, Apartado Postal 70-367, Mexico, DF, 04510, Mexico
7 - Oberlin College, Department Of Biology, 119 Woodland St., Science Center K111, Oberlin, OH, 44074, United States

Keywords:
gypsum
Asteraceae
phylogeny
Mexico
Coahuila.

Presentation Type: Poster This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PSY007
Abstract ID:272
Candidate for Awards:None


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