Abstract Detail

Hybrids and Hybridization

McCauley, Ross [1], Swindell, Emily [2], Tabb, Stacey [2].

Incongruence of nuclear and plastid markers supports the hybrid origin of the edaphic endemic Packera mancosana (Asteraceae: Senecioneae) in southwestern Colorado.

Packera mancosana is a recently described rare species restricted to an area of Mancos Shale barrens in Lone Mesa State Park in Southwestern Colorado. The population of P. mancosana is extremely small consisting of approximately 400 plants over an area of 3-5 hectares and it shares the site with other rare species including Gutierrezia elegans and Physaria pulvinata. The species is closely allied to the widespread and morphologically variable P. werneriifolia and the segregation of P. mancosana from P. werneriifolia has been questioned. To investigate the distinction and origin of P. mancosana we performed morphometric analysis on population samples of Packera species from around the Four Corners region and developed multi-gene phylogenies for both plastid (rpl32-trnL, rps15-ycf1, trnV-ndhC, petL-psbE, and psbJ-petA) and nuclear (ITS and WAXY) regions. Morphologically P. mancosana is divergent from other Packera taxa in the region. Nuclear genetic data does support a close relationship between P. mancosana and P. werneriifolia although plastid markers suggest a sister relationship to other Packera species including P. crocata and P. neomexicana. This incongruence of genetic markers coupled with unique morphology in this shale barren habitat suggests a hybrid origin and adaptation to the unique soil substrate. Our work has also shed light on the prevalence of gene exchange among multiple divergent species within Packera of the Four Corners region and highlights the difficulty of assigning taxa within this hybridizing complex.

1 - Fort Lewis College, Department Of Biology, 1000 Rim Drive, Durango, CO, 81301, United States
2 - Fort Lewis College, Department of Biology, 1000 Rim Dr., Durango, CO, 81301, USA

Keywords:
Asteraceae
edaphic
endemic
Hybridization
Colorado.

Presentation Type: Poster
Session: P, Hybrids and Hybridization
Location: Grand Ballroom - Exhibit Hall/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 5:30 PM 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: PHH003
Abstract ID:781
Candidate for Awards:None