Abstract Detail

Hybrids and Hybridization

Persinger, Jessica [1], Thompson, Pamela [2], Diaz, Nicolas [3], Hendrickson, Elizabeth [4], Katie, Gerloff [2], Katie, Kline [2], Cruzan, Mitchell [5].

Reproductive isolation between a widespread and range-limited Ranunculus species.

Hybridization has the potential to contribute to adaptation and diversification, but poses a threat to the persistence of divergent lineages when considering excessive gene flow. The fate of range-limited species is of particular concern when they are hybridizing with more common species due to the potential for genetic swamping. Species may be rare because of historical range contraction, or they may be recently derived and occupy stable or expanding ranges. Based on phenotypic traits, we identified a narrow hybrid zone between the range-limited Ranunculus austro-oreganus and its widespread congener, R. occidentalis. We verify the presence of a hybrid zone by quantifying morphological traits and characterizing the distribution of genetic variants based on genome-wide SNP surveys. We test the strength of reproductive isolation using greenhouse crosses, estimates of flowering time based on herbarium records, and geographic and ecological isolation based on environmental niche modeling. Interspecific and intraspecific crosses along with a lack of strong ecological and phenological differences indicate that these species are not strongly reproductively isolated. A strong signature of homozygosity across populations and lower seed production after selfing and outcrossing in R. austro-oreganus suggests high levels of drift load, which is indicative of a recent genetic bottleneck. Continued hybridization may be a threat to the persistence of the range-limited R. austro-oreganus.

1 - Portland State University, Biology, 1719 SW 10th Ave., SRTC Room 246, Portland, OR, 97201, United States
2 - Portland State University, 1719 SW 10th Avenue, SRTC Rm 246, Portland, OR, 97201, United States
3 - Portland State University, Biology Department, 1719 SW 10th Avenue, SRTC Rm 246, Portland , OR, 97201, United States
4 - Portland State University, Biology, 1719 SW 10th Avenue, SRTC Rm 246, Portland, OR, 97201, United States
5 - Portland State University, Department Of Biology, 1719 SW 10th Ave, SRTC Rm 246 - Biology, Portland, OR, 97201, United States

Keywords:
reproductive isolation.

Presentation Type: Oral Paper
Session: HYHY1, Hybrids and Hybridization
Location: Tucson H/Starr Pass
Date: Wednesday, July 31st, 2019
Time: 9:30 AM
Number: HYHY1005
Abstract ID:204
Candidate for Awards:None