Abstract Detail

Hybrids and Hybridization

McElwee-Adame, Alexandra [1], Silva, Kiley [1], Gonzalez Elizondo, Socorro [2], Gonzalez Elizondo, Martha [2], Flores-Renteria, Lluvia [3].

Multidirectional hybridization challenges species boundaries within the plant genus Arbutus of Mexico.

It is estimated that somewhere between 30-70% of extant flowering plants have experienced a hybridization event at some point in their evolutionary history. Species in the genus Arbutus are suspected to hybridize based on morphology, however, no studies have applied genomic approaches to the species distributed throughout mainland Mexico (A. arizonica, A. bicolor, A. madrensis, A. mollis, A. occidentalis, A. tessellata, A. xalapensis), leaving a gap in our understanding of the species boundaries within this system. Additionally, field observations have noted high levels of overlapping distribution, with as many as five species found in the same locality, possibly allowing hybridization to occur. Field observations further note that many suspected hybrid combinations may occur, many between A. bicolor, A. madrensis, A. tessellata and A. occidentalis, blurring our understanding of where species boundaries may be drawn in this genus. Therefore, our study aims to apply a genomic approach to determine how species that occur sympatrically are influenced levels of gene flow interspecifically and elucidate species boundaries as well as determine the patterns of hybridization. We hypothesize that all species that occur sympatrically will exhibit varying levels of hybridization. Using DArT genomic data, we applied both a model based, and non-model based hierarchical population genetics approach to determine species boundaries between the overlapping Arbutus species as well identifying hybrid individuals. Our study was able to correctly identify five observed hybrid crosses as well as a novel cross between A. arizonica and A. occidentalis. With many of these species residing within the Madrean Pine-Oak Woodlands biodiversity hotspot, we hope that results of this study inform important conservation decisions within this critical region as well as further our understanding of how species behave under varying levels of overlapping distribution.

1 - San Diego State University, Biology, 5500 Campanile Drive, San Diego, CA, 92182, United States
2 - CIIDIR Durango (IPN), Sigma 119, 20 de Noviembre II, Durango, Durango, 34220, Mexico
3 - San Diego State University, 4319 Yale Ave, San Diego State University, La Mesa, CA, 91942, United States

Keywords:
hybridization
Ericaceae
Population genomics
Species Boundaries.

Presentation Type: Oral Paper
Session: HH1, Hybrids and Hybridization I
Location: /
Date: Wednesday, July 21st, 2021
Time: 11:00 AM(EDT)
Number: HH1005
Abstract ID:1136
Candidate for Awards:Margaret Menzel Award