Abstract Detail

Systematics

Fehlberg, Shannon [1], Prather, Alan [2], Ferguson, Carolyn [3].

Patterns of ecological and genetic diversification among diploids, tetraploids, and hexaploids in closely related taxa of Phlox (Polemoniaceae).

Renewed attention to polyploidy, or whole genome duplication, over the last decade has resulted in a greater appreciation for its ubiquity and importance. However, as recent reviews suggest, numerous questions about its influence on various aspects of plant diversity remain. To better understand the contribution of polyploidy to diversity, research documenting the consequences of polyploidy across a spectrum of biological, genetic, morphological, ecological, and physiological dimensions, in a comparative phylogenetic context, is needed. Here we report on our ongoing research in the genus Phlox (Polemoniaceae), an important, non-model species group for elucidating the contributions of polyploidy to different aspects of diversity, evolution, and speciation. Polyploidy is well known in Phlox, and recent studies employing flow cytometry have greatly increased our knowledge of the distribution of polyploidy in the genus, including documentation of cytotypic variation within species. Cytotypic variation has been most thoroughly documented in three closely related Phlox taxa distributed in the mountains and high plains of the southwestern United States and northern Mexico: P. amabilis, P. nana and P. woodhousei. Each of these species occurs as diploid, tetraploid and hexaploid populations with some overlap in distribution of cytotypes at a coarse geographic scale. Using a combination of carefully curated occurrence data, flow cytometry data linked with chromosome counts, characterizations of both geographic and environmental niche space, comparisons of niche breadth and optima, and phylogenetic analysis of chloroplast sequences, we determined the patterns of ecological and genetic diversification among species and cytotypes for P. amabilis, P. nana, and P. woodhousei. Results from analyses of ecological niche among the three species indicate significant niche divergence for all measures. Results among cytotypes within species indicate both niche conservatism (three of seven comparisons) and niche divergence (four of seven comparisons), with consistency among various measures. Results from phylogenetic analyses indicate several supported clades corresponding to taxonomy, multiple origins of polyploidy within species (predominantly autopolyploidy), and instances of hybridization across all three species. Taken together, these results can be used to understand ecological differentiation of species and cytotypes in a phylogenetic context. As we continue to build these various types of data sets and comparisons across multiple species complexes, we advance our ability to address critical questions of broad interest concerning the contribution of polyploidy to diversity.

1 - Desert Botanical Garden, Research, Conservations, and Collections, 1201 North Galvin Parkway, Phoenix, AZ, 85008, United States
2 - Michigan State University, PLANT BIOLOGY, Plant Biology Laboratories, 612 Wilson Rd, Rm 166, East Lansing, MI, 48824, United States
3 - Kansas State University, Biology, Division Of Biology, Ackert Hall, Manhattan, KS, 66506, United States

Keywords:
polyploidy
ecological niche modelling
Phylogenetics
flow cytometry
Phlox
Polemoniaceae
cytotype.

Presentation Type: Poster
Session: P, Systematics Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
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: PSY011
Abstract ID:336
Candidate for Awards:None