Abstract Detail

Systematics Section/ASPT

Liston, Aaron [1], Weitemier, Kevin [2], Kronmiller, Brent [3], Zarrei, Mehdi [4], Dickinson, Tim [5].

Using Hyb-Seq data to test phylogenetic hypotheses in hawthorns (Crataegus, Rosaceae).

Recently, the “Crataegus problem” (limited morphological variation, apomixis, hybridization, polyploidy) became markedly more tractable with the availability of flow cytometric determinations of ploidy level, and phylogenetic inferences based on DNA sequence data. However, phylogenetic inferences to date are based on only a small number of nuclear and chloroplast loci of relatively limited resolution. To greatly increase the number of loci available for phylogenetic analysis in Crataegus, target enrichment baits were designed for 1254 exons from 257 nuclear genes, using the published apple genome as a reference. Genomic libraries were constructed for 24 Crataegus accessions representing 12 diploids and four tetraploids, and all seven major clades. Solution hybridization and Illumina sequencing yielded an average of 1000 exons and 345,000 base pairs of nuclear sequence per accession. In addition, an average of 105,000 base pairs of chloroplast sequence was obtained per accession. We will test support for the topology obtained previously using diploid accession species trees rooted using the apple sequences. By including tetraploids from predominantly eastern North American Crataegus section Coccineae we will test the conclusions from earlier work that two tetraploids in C. section Douglasia originated from separate hybridizations between Douglasia diploids and Coccineae tetraploids. Analyses of the concatenated chloroplast sequence data will provide a maternal phylogeny with which to compare the species trees obtained from the nuclear loci.

Related Links:
Black-fruited hawthorns of North America

1 - Oregon State University, Department Of Botany & Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331-2902, USA, 541/737-5301
2 - Oregon State University, Botany And Plant Pathology, Cordley Hall 2082, Corvallis, OR, 97331, USA
3 - Oregon State University, Center for Genome Research and Biocomputing, 3021 ALS Building, Corvallis, OR, 97331-7303, USA
4 - The Centre for Applied Genomics (TCAG), The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay St, Toronto, ON, M5G 0A4, Canada
5 - Royal Ontario Museum, Natural History, 100 Queen's Park, Toronto, ON, M5S 2C6, Canada

Keywords:
diploid
tetraploid
gametophytic apomixis
hybrids.

Presentation Type: Oral Paper:Papers for Sections
Session: 49
Location: Salon 4/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 4:30 PM
Number: 49012
Abstract ID:1004
Candidate for Awards:Margaret Menzel Award