Abstract Detail

Genetics Section

Alexander, Patrick J. [1], Beck, James [2], Windham, Michael [2], Allphin, Loreen [3], Al-Shehbaz, Ihsan [4], Bailey, C. Donovan [5].

From one, many: divergent and reticulate speciation within Boechera fendleri sensu lato (Brassicaceae).

Boechera is a taxonomically complex and almost exclusively North American genus that has become a model system for a diverse array of studies. It is proving particularly useful in studies of apomixis and hybrid polyploid speciation, both of which are rampant in the group. The genus includes about 70 sexual diploid species, along with ca. 40 named (and many additional unnamed) apomictic triploid hybrids. Diploid hybrids have been considered rare, leading to the belief that most of the apomictic triploids are either autopolyploids or digenomic triploids (with the dominant genome contributed by a sexual diploid producing rare, unreduced gametes). Here we present gene sequence and microsatellite data from the B. fendleri complex that challenge this assumption. Boechera fendleri sensu lato consists of three divergent diploid species ranging from northern Colorado to western Texas; north to south, these are B. spatifolia, B. fendleri, and B. texana. Microsatellite data indicate that the two northern elements, B. fendleri and B. spatifolia have crossed repeatedly to produce a genetically variable, diploid hybrid. This taxon has subsequently hybridized with B. texana to form a trigenomic hybrid species.

Broader Impacts:

1 - New Mexico State University, Department of Biology, 248 Foster Hall, Las Cruces, NM, 88003, USA
2 - Duke University, Department of Biology, 139 Biological Sciences Building, PO Box 90338, Durham, North Carolina, 27708, USA
3 - Brigham Young University, Department of Plant and Animal Sciences, 275 Widtsoe Building, Provo, UT, 84602, USA
4 - Missouri Botanical Garden, Po Box 299, St Louis, Missouri, 63166-0299, USA
5 - New Mexico State University, Department of Biology, 263 Foster Hall, Las Cruces, NM, 88003, USA

Keywords:
Boechera
Brassicaceae
hybrid speciation
microsatellites
allopolyploid.

Presentation Type: Oral Paper:Papers for Sections
Session: 22
Location: 553B/Convention Center
Date: Monday, August 2nd, 2010
Time: 4:45 PM
Number: 22005
Abstract ID:684