Systematics/Phytogeography / Taxonomie/ Section
Tsou, Chih-Hua , Vijayan, Kunjupillai , Zhang, Wenju .
Molecular phylogeny of Camellia (Theaceae) as inferred from nrITS.
Camellia, of the family Theaceae, is an economically important genus, because of its utilization in beverage (tea), oil and horticultural industries. The taxonomic treatment of this genus is still a matter of great controversies as evident from the two recent and widely followed classifications (Chang 1988; Ming 2000). These two classifications vary widely in the treatments at species, sectional, and subgeneric levels. In order to understand the phylogeny of Camellia, we undertook nrITS sequencing. Genomic DNA from 87 species were extracted, PCR amplified, cloned the PCR product, and at least 10 clones from each leaf sample were sequenced. Multiple alignments showed intraindividual variation in many species, thus, a gene tree was constructed with 143 sequences from our 87 species and 13 sequences of golden camellias obtained from genebank. In the gene tree, most of the sequences of the same species grouped together under the same clade. We further choused one sequence from each species to construct the species tree. The gene trees and the species trees were highly congruent in topology. The species tree was resolved into seven major clades and a few small groups, which failed to support any of the existing classifications. While supporting the monophyletic nature of the sections Thea and Furfuracea and the unification of sections Theopsis and Eriandra, it revealed many interesting and important points like the paraphyletic nature of sections¬†Camellia and Paracamellia, the settlement of C. piquetiana and C. yunnanensis within the clade of golden camellias, etc. Further, it is observed that the division of the genus Camellia into subgenera based on presence or absence of pedicel was not supported, though grouping on the basis of fusion of style and filaments, numbers of carpels in the ovary, locules in the fruit, and seeds in the locule showed good correlations.
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1 - Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, 11529, Republic of China
2 - Department of Ecology and Evolutionary Biology, Fudan University, Shanghei, 200433, China
Presentation Type: Oral Paper:Papers for Sections
Location: Room 3/Woodward
Date: Monday, July 28th, 2008
Time: 3:00 PM