Premise Of The Study: Unrecognized variation in ploidy level can lead to an underestimation of species richness and a misleading delineation of geographic range. (Ranunculaceae) comprises a complex of hexaploids (6), rare nonaploids (9), and dodecaploids (12), all with unknown distributions. We delineate the geographic distribution and contact zones of the cytotypes, investigate morphologies of cytotypes and subspecies, and discuss the biogeography and evolutionary history of the polyploid complex.

Methods: Using cytologically determined specimens as reference, propidium iodide flow cytometry was performed on silica-dried samples and herbarium specimens from across the range of s.l. Genome size estimates from flow cytometry were used to infer cytotypes. A key morphological character, leaf length-to-width ratio, was measured to evaluate whether these dimensions are informative for taxon and/or cytotype delimitation.

Key Results: Dodecaploids were more northerly in distribution than hexaploids, and a single midlatitude population in the Northern Rockies yielded nonaploids. Genome size estimates were significantly different between all cytotypes and between hexaploid subspecies. Leaf length-to-width ratios were significantly different between subspecies and some cytotypes.

Conclusions: presents clear patterns of cytotype distribution at the large scale. Marked differences in morphology, range, and genome size were detected between the hexaploid subspecies, subsp. in the Cascade-Sierra axis and subsp. in the Rockies. Sympatry between cytotypes in the Cascades and a parapatric distribution in the Northern Rockies suggest unique origins and separate lineages in the respective contact zones.

Download full-text PDF

Source
http://dx.doi.org/10.3732/ajb.1600365DOI Listing

Publication Analysis

Top Keywords

genome size
12
contact zones
8
flow cytometry
8
range genome
8
size estimates
8
leaf length-to-width
8
northern rockies
8
hexaploid subspecies
8
cytotypes
5
cytogeography subalpine
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!