Economic Botany Section
Govindarajulu, Rajanikanth , Hughes, Colin E. , Robertson, Ashley , Bailey, C. Donovan .
Phylogenetic jumping beans: inferring relationships among diploid species of Leucaena with conflict among and within data partitions.
The genus Leucaena comprises a complex assemblage of wild diploid species and derived wild and semi-domesticated polyploids. Interest in understanding the relationships and origins of polyploidy in Leucaena has been sparked by reticulate evolutionary patterns in the genus, attempts to understand processes of incipient indigenous domestication, and to underpin breeding of this economically important forage crop. Initial studies to tease apart divergence and reticulation in Leucaena suggested hybrid origins for a number of polyploid taxa. However, the specific origins of most of the polyploids remain elusive due to limited resolution and support among diploid species in the existing gene trees. Here, we investigate relationships among diploids with particular emphasis on L. lanceolata, one of the putative parents of the pantropically cultivated polyploid L. leucocephala. Phylogenetic analyses of eight independent DNA sequence-based markers (three chloroplast [two trnK introns flanking the matK gene and psbA-trnH] and seven nuclear-encoded loci [nrDNA ITS and six anonymous SCAR-based loci - 23L, A9, 28, PA1213, A4A5, A2]), including 53 accessions representing all 17 diploids were conducted. Results from the analyses of separate and combined matrices identify considerable conflict among gene-trees for these morphologically diverse diploids, including accessions of L. lanceolata. We discuss lack of informative sequence variation, hybridization, recombination, and species delimitation issues, as possible explanations for these conflicting placements of L. lanceolata.
Log in to add this item to your schedule
1 - New Mexico State University, Biology, Msc 3af, Las cruces, New Mexico, 88001, USA
2 - University of Oxford, Department of Plant Sciences, South Parks Road, Oxford, Oxfordshire, OX1 3RB, United Kingdom
3 - University of Bristol, School of Biological Sciences, Woodland Road, BS8 1UG, Bristol, UK
4 - New Mexico State University, Department of Biology, Po Box 30001, Department 3Af, Las Cruces, New Mexico, 88003-8001, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Magpie B/Cliff Lodge - Level B
Date: Tuesday, July 28th, 2009
Time: 2:45 PM