Systematics Section / ASPT
Yi, Tingshuang , Miller, Allison J. , Wen, Jun .
Phylogenetic and biogeographic diversifications of Rhus (Anacardiaceae) in the Northern Hemisphere.
Sequences of internal transcribed spacers (ITS) and the third intron of the nuclear nitrate reductase (NIA-i3) gene, and the chloroplast ndhF gene and two noncoding regions (trnL intron, and trnL[UAA] 3’ exon-trnF [GAA] intergenic spacer) were used for phylogenetic analyses of Rhus. The aligned matrix of Rhus species for ITS data had a length of 742 characters with 96 variable and 72 parsimony-informative sites, and NIA-i3 had 707 characters with 118 variable and 55 pasimony-informative sites. Both the nuclear and chloroplast DNA data sets support the monophyly of Rhus. The monophyly of subgenus Rhus was supported by NIA-i3, and largely supported in chloroplast DNA data except R. microphylla of subgenus Lobadium was nested within. The monophyly of subgenus Lobadium was supported in the ITS and NIA data, whereas cpDNA data revealed two main clades within the subgenus, which formed a trichotomy with the clade of subgenus Rhus plus R. microphylla. The ITS, NIA, and cpDNA trees provided largely congruent results, but differed in the positions of R. coriaria, R. michauxii, R. microphylla, R. rubifolia. Hybridization and introgression among the Rhus species may explain the discordance between nuclear and chloroplast data. The Hawaiian R. sandwicensis was suggested to have derived from a common ancestor with R. chinensis in Asia, and was estimated to have dispersed from Asia about 17 million years ago using the penalized likelihood method.
1 - Washington University, Department of Biology, 1 Brookings Drive, Rebstock Hall, St. Louis, Missouri, 63130-4899, USA
2 - Field Museum, Botany Department, 1400 S. Lake Shore Dr., Chicago, Illinois, 60605-2496, USA
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM