A Phylogenetic Analysis within Tribes Gloxinieae and Gesnerieae (Gesnerioideae: Gesneriaceae)
The evolution of floral symmetry in Asteridae has been of recent interest. Three genera with full or partial radial floral symmetry are found within tribes Gesnerieae and Gloxinieae of Gesneriaceae where the remaining taxa have bilaterally symmetrical flowers. These tribes have been shown to each be monophyletic and to be sister to each other, but a full analysis within each tribe has not demonstrated strongly supported sister group relationships among genera, especially those with radially symmetrical flowers. To assess sister group relationships more accurately, a phylogenetic analysis using GCYC (a Gesneriaceae homolog of CYCLOIDEA) sequences as well as four regions from the chloroplast genome (ndhF, trnL intron, trnF-trnL spacer, rpl20-rps12 spacer), ITS, and two paralogues of the nuclear encoded chloroplast expressed glutamine synthetase was conducted. The analyses for the most part resolved sister group relationships between radial and bilateral taxa with strong support as well as provided support for several clades within Gloxinieae and indicated that Phinaea is not a monophyletic genus.
James F. Smith, Scottie B. Draper, Lena C. Hileman, and David A. Baum. "A Phylogenetic Analysis within Tribes Gloxinieae and Gesnerieae (Gesnerioideae: Gesneriaceae)" Systematic Botany 29.4 (2004): 947-958.