Abstract Detail

Conservation Biology

Fehlberg , Shannon D [1], Allen, Jessica M [1], Church, Kathleen [1].

Distinguishing Arizona hedgehog cactus, a federally endangered species, from its close relatives using genetic information.

The Arizona hedgehog cactus, Echinocereus arizonicus subsp. arizonicus, is a narrow endemic known from a highly localized area in central Arizona between the towns of Superior, Miami and Globe. In order to address real and significant threats facing E. arizonicus subsp. arizonicus, basic information about its taxonomy and that of closely related species in Echinocereus section Triglochidiatus must be resolved. Our current knowledge of species, subspecies, and varieties of taxa within this section is confounded by widely varying and overlapping morphological characters found within populations, across geographic regions, and across taxa. However, the addition of genetic data to our current understanding of morphology, ploidy level, and distribution patterns in Echinocereus section Triglochidiatus may enable us to form stronger species definitions, make more accurate field identifications, and begin to clarify long-standing taxonomic confusion in the group. In order to acquire such genetic data, 47 populations representing all focal taxa (E. arizonicus subsp. arizonicus, E. arizonicus subsp. nigrihorridispinus, E. coccineus, E. santaritensis, E. triglochidiatus var. mojavensis, and E. triglochidiatus var. triglochidiatus) were visited, and more than 215 spine and/or floral tissue samples were taken. Data for one nuclear and two chloroplast DNA sequence regions and four nuclear microsatellite regions were obtained. Results presented here indicate that there are at least three distinct genetic groups based on shared multilocus genotypes in this study system: the diploid E. arizonicus subspecies, the diploid E. triglochidiatus varieties, and the tetraploid E. coccineus and E. santaritensis, and there is some level of genetic differentiation among populations and taxa. Although these results should be considered preliminary because of their limited scope, they do provide evidence that continued genetic investigations hold promise for the resolution of difficult relationships among the red-flowered hedgehog cacti.

1 - Desert Botanical Garden, 1201 N. Galvin Pkwy., Phoenix, AZ, 85008, USA

Keywords:
Cactaceae
conservation genetics
population genetics
Echinocereus
polyploidy
microsatellites.

Presentation Type: Oral Paper:Papers for Topics
Session: 16
Location: Firs North/Boise Centre
Date: Tuesday, July 29th, 2014
Time: 11:00 AM
Number: 16012
Abstract ID:268
Candidate for Awards:None