ibclogo XVI International Botanical Congess

Abstract Number: 4340
Poster No. = 846


PHYLOGENETIC ANALYSIS OF THE EXOCHORDA COMPLEX (ROSACEAE) BASED ON MOLECULAR DATA


Fangyou Gao and Daniel Potter, Dept. of Pomology, University of California, Davis, CA 95616, U.S.A.


Sequence data from ITS regions of nuclear rDNA and matK of cpDNA were used to study phylogenetic relationships in the Exochorda complex. Spiraea, Prunus, Oemleria and Rosa were also included in this study. Both gene regions strongly supported the monophyly of Exochorda with Oemleria as the sister taxon. Previous systematic research suggested that Exochorda could be divided into three subspecies. ITS data supported a clade composed of E. r. subsp. racemosa plus E. r. subsp. giraldii with E. r. serratifolia as the sister group. The matK data weakly supported the monophyly of E. r. subsp. racemosa. Morphological evolution of the genus is discussed and a hypothesis is presented to explain the origin and distribution of the genus in this paper.Key words: Biogeography, Exochorda, ITS, matK, molecular phylogenetics, Rosaceae.

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