Systematics Section / ASPT
Danderson, Clark A. , Downie, Stephen R. .
Resolving phylogenetic relationships within the apioid superclade (Apiaceae subfamily Apioideae) using cpDNA sequence data, with emphasis on tribe Apieae.
Previous molecular systematic studies into the higher-level relationships of Apiaceae subfamily Apioideae have revealed a strongly supported clade heretofore unrecognized in prior taxonomic treatments. This group of flowering plants, provisionally recognized as the apioid superclade (Plunkett and Downie, 1999), comprises some 300 genera of largely north temperate distribution. Traditionally, these genera were classified into no fewer than five putatively unrelated tribes with dubious circumscriptions. Within the apioid superclade, seven tribes are confirmed as monophyletic (Apieae, Careae, Echinophoreae, Pimpinelleae, Pyramidoptereae, Selineae, and Tordylieae). Some of these tribes maintain long-standing names, but they are radically different in generic composition from those groups originally recognized. In addition, there are numerous genera of uncertain tribe or clade placement, thus it is not unrealistic to presume that further studies of the group will reveal additional tribes within the superclade. Many genera are of exceptional taxonomic difficulty and their delimitation and infrageneric relationships will only be resolved through international collaborative effort. The resolution of intergeneric and tribal relationships within the apioid superclade, as well as its precise circumscription, is poor and is one of the last major problems of Apiaceae higher-level systematics. To resolve issues of relationships (and, ultimately, to produce a revised classification of the group), sequence data are being obtained from the cpDNA trnQ-trnK 5’exon region, which includes two large intergenic spacers and the rps16 intron. Additional data may come from other noncoding cpDNA loci. Sampling is based on the results of many recently published studies using nrDNA ITS sequences and those taxa that have been recalcitrant to proper phylogenetic placement using existing cpDNA sequence and restriction site data. Emphasis is placed on tribe Apieae, which contains many economically important plants. Results to date suggest that adequate resolution will be achieved to resolve higher-level relationships within the apioid superclade.
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1 - University of Illinois Urbana, Department of Plant Biology, 265 Morrill Hall, 505 South Goodwin Avenue, Urbana, Illinois, 61801-3707, USA
Presentation Type: Poster:Posters for Sections
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM