Abstract Detail


McGarvey, Luisa  [1], Jiao, Lynn [2], Douglas, Norman [3], Flores, Hilda [4], Ochoterena, Helga [5], Moore, Michael [1].

Exploring species boundaries of Thelesperma (Asteraceae) on gypsum using phylogenetic and morphometric analysis.

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 grow only on the substrate gypsum and are adapted to nutrient-poor conditions. Thelesperma (Asteraceae: Coreopsideae) is a genus of thirteen species that often occupy gypsum in the Chihuahuan Desert region of northern Mexico and southwestern USA, including one species restricted to gypsum. 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). This sequence data revealed that populations of T. longipes and T. megapotamicum possess diverse sequences that group into a few distinct clades, possibly representing new species. Therefore, the current study aimed to test whether individual clades of these two species are morphologically coherent but distinctive from each other, through morphometric analysis of vegetative and reproductive characters. Herbarium samples were used for morphometric analysis. The morphometric data collected suggests that there is some morphological variation between the reproductive characters in the T. longipes clades,  T. megapotamicum clades, and between T. longipes and T. cf. longipes.

1 - Oberlin College, Department Of Biology, 119 Woodland St., Science Center K111, Oberlin, OH, 44074, United States
2 - Oberlin College, Department of Biology, 119 Woodland Street, Oberlin, OH, 44074, USA
3 - University Of Florida, Biology, PO Box 118525, Gainesville, FL, 32611, United States
4 - Instituto De Biologia, UNAM, Departamento de Botanica, Apdo.Postal 70-367, Mexico, DF, 04510, Mexico
5 - Instituto De Biología, UNAM, Botanica, Depto Botánica-Apdo.Postal 70-367, Coyoacan, Mexico DF, 04510, Mexico

species boundaries

Presentation Type: Poster
Session: P, Systematics Posters
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 5:00 PM Time and date to be determined
Number: PSY006
Abstract ID:284
Candidate for Awards:None

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