Abstract Detail

Systematics Section/ASPT

morin, david [1], ALEXANDER, PATRICK [2], BECK, JAMES [3], Windham, Michael D [4], Li, Fay-Wei [5], Rushworth, Catherine [6], Al-Shehbaz, Ihsan [7], Allphin, Loreen [8], Bailey, C. Donovan [9].

Identifying the sexual diploid members of the Boechera suffrutescens (Brassicaceae) Complex.

Boechera provides a unique opportunity to investigate the evolutionary roles of hybridization, apomixis, and polyploidization in a diverse genus closely related to Arabidopsis.  Boechera is particularly noteworthy because it includes an abundance of diploid and triploid species that have arisen via hybridization and become established through apomixis. Given the complexity of this reticulate speciation, it is necessary to characterize/define the divergent sexual diploid lineages before addressing the origins of hybrid lineages. In this study, we focus on the Boechera suffrutescens complex, a northwestern U.S. clade whose diploid species include the widespread B. suffrutescens and two narrowly distributed serpentine endemics, B. constancei and B. rollei.  Here we present an analysis of the sexual diploid members of the complex based on multilocus data from 15 microsatellite loci genotyped in 307 individual samples from across the geographic range of the complex. Our results support the recognition of B. rollei and B. constancei as discrete taxa, and unexpectedly reveal that B. suffrutescens includes three divergent sexual diploid lineages. One of these, which includes the type specimen of B. suffrutescens, is restricted to Idaho and eastern Oregon; the others (including the type specimen of Arabis duriuscula) are distributed along  the Sierra Nevada/Cascade axis. Our data also reveal a high degree of differentiation between populations of B. constancei, most likely caused by the highly fragmented distribution of its serpentine habitat. Within the B. suffrutescens complex, our 15 locus microsatellite dataset provides both critical taxonomic resolution and the population genetic data needed to strengthen conservation plans for the rare endemics. 

1 - New Mexico State University, Biology, PO Box 30001, 3AF, Las Cruces, NM, 88003, USA
2 - New Mexico State University, Biology Department, 248 Foster Hall, MSC 3AF, Las Cruces, NM, 88003, USA
3 - Wichita State University, Biology, 1845 Fairmount, Box 26, Wichita, KS, 67260-0026, USA
4 - Duke University, Department of Biology, Box 90338, Durham, NC, 27708, USA
5 - Duke University, Biology, Box 90338, Durham, NC, 27708, USA
6 - Duke University, PO Box 90338, Durham, NC, 27708, USA
7 - Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166-0299, USA
8 - Brigham Young University, DEPT INTEGRATIVE BIOLOGY, 275 WIDB, Provo, UT, 84602, USA
9 - New Mexico State University, PO Box 30001 MSC 3AF, Las Cruces, NM, 88003, USA

Keywords:
microsatellites
population structure
conservation genetics
Brassicaceae
Boechera
Serpentine.

Presentation Type: Oral Paper:Papers for Sections
Session: 14
Location: Cottonwoods North/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:15 PM
Number: 14015
Abstract ID:796
Candidate for Awards:None