Abstract Detail



Phylogenomics

Abair, Alexander [1], Dugas, Diana [1], Madhugiri, Nageswara-Rao [1], Hughes, Colin [2], Bailey, C. Donovan [1].

Developing Phylyogenetic Hypotheses for Leucaena through Reference Guided and de novo Transcriptomics .

The genus Leucaena (Leguminosae, Caesalpinioideae, Mimosoid clade) is comprised of 24 species with native ranges extending from southern USA to Peru.  Several of these species have historical and contemporary use in Mesoamerica as food, shade, and soil fertilizers.  Some species (most notably Leucaena leucocephala) have spread around the world where they are used as cattle fodder, biofuels, shade, and soil amendments in tropical agroforestry systems.  The evolutionary history of this genus includes an ancient polypoidization event, subsequent diploidization, and diversification into 19 described diploid taxa.  Five additional allotetraploid species originated through the process of spontaneous backyard hybridization from the human-translocated diploid species.  Although the precise relationships of these species remain unclear, previous work has inferred three well-supported diploid clades.  However, the placement of one species (Leucaena cuspidata) as well as the relationships among species within the largest clade (Clade 1) remain poorly resolved.  Since all hybrid species have a parent in Clade 1, the uncertainty of relationships within that clade prevents reliable inference of allotetraploid origins.  This study uses a sequenced genome from the diploid Leucaena trichandra and whole seedling-derived transcriptomes from all Leucaena species to infer a more robust species tree for the diploids.  Both reference-guided and de novo approaches are used to investigate conserved orthologous genes from the transcriptome data.  Using the phylogeny inferred from these methods, patterns of evolution will be tied to patterns in biogeography using a well-curated set of Leucaena herbarium specimens. 


1 - New Mexico State University, Department Of Biology, PO Box 30001, MSC 3AF, Las Cruces, NM, 88003, United States
2 - University Of Zurich, Institute Of Systematic Botany, Zollikerstrasse 107, Zürich, 8008 Zürich, Switzerland

Keywords:
Leucaena
Leguminosae
Polyploid
phylogeny
genomics
Transcriptomics
hybridization
orthology
paralogy.

Presentation Type: Oral Paper
Number:
Abstract ID:923
Candidate for Awards:None


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