Abstract Detail

Systematics Section/ASPT

Chansler, Matt [1], Ferguson, Carolyn J [2], Fehlberg , Shannon D [3], Prather, Alan [4].

Analysis of Morphological Variation between Diploid, Tetraploid, and Hexaploid Phlox amabilis.

Polyploidy has been established as an important factor in evolution and ecology of flowering plants.  A better understanding of the kind and degree of morphological differentiation among ploidy levels within a species can help explain further how polyploidy generates biodiversity.  Which morphological characters and/or groups of characters vary with ploidy?  How much variation can be explained by ploidy?  Are associations between morphology limited to those kinds of characters typically studied? We focus on establishing a foundational assessment of morphological variation within Arizona phlox, Phlox amabilis.  Prior work has indicated that this species of conservation concern, endemic to Arizona, contains plants of three ploidy levels: diploid, tetraploid, and hexaploid.  We collected plant material and recorded data from 11 populations of P. amabilis, including almost all known populations.   A wide array of morphological characters was measured in the field and in the lab for 25 plants at each population: four micromorphological, eight vegetative, and 13 reproductive.  For those populations not previously characterized, ploidy was determined by flow cytometry.  Most populations have a single cytotype, although one contains both diploid and tetraploid individuals, as well as two putative triploids.  Mixed-model statistics indicate that most characters differ significantly between ploidy levels.  Cell size, observed using stomata and pollen grains, was significantly larger in both tetraploids and hexaploids than in diploids, confirming a widely-observed pattern.  Notable differences were found in most characters, with representation from micromorphological, vegetative, and reproductive categories.  Each ploidy level also differed from one or both other ploidy levels in at least one character.  In the future, we will use these morphological data in tandem with phylogeny, population genetics, and species distribution to build a more complete picture of the role of ploidy in evolution and ecology in P. amabilis and its close relatives.

1 - Michigan State University, Plant Biology, 612 Wilson Road, East Lansing, MI, 48823, USA
2 - Kansas State University, Division of Biology, Ackert Hall, Manhattan, KS, 66506-4901, USA
3 - Desert Botanical Garden, 1201 N. Galvin Pkwy., Phoenix, AZ, 85008, USA
4 - Michigan State University, Plant Biology, 612 Wilson Road, East Lansing, MI, 48824, USA

Keywords:
polyploidy
Morphology
phlox
Polemoniaceae
chansler
fehlberg
ferguson
prather
ploidy
Arizona
stomata
collaboration.

Presentation Type: Oral Paper:Papers for Sections
Session: 30
Location: Payette/Boise Centre
Date: Tuesday, July 29th, 2014
Time: 4:45 PM
Number: 30012
Abstract ID:411
Candidate for Awards:None