Plant Diversity ›› 2011, Vol. 33 ›› Issue (5): 465-476.DOI: 10.3724/SP.J.1143.2011.11075

• Articles •     Next Articles

The Systematic Placement of the Monotypic Genus Paraisometrum (Gesneriaceae) Based on Molecular and Cytological Data

 TAN  Ying-1、2,   Wang-Zhi-1、3,   Sui-Xue-Yi-1、4,   Hu-Guang-Wan-1   

  1. 1 Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; 2 Graduate University of Chinese
    Academy of Sciences, Beijing 100049, China; 3 School of Forestry, Southwest Forestry University, Kunming
    650224, China; 4 College of Agronomy, Yunnan Agricultural University, Kunming 650201, China;
    5 Department of Biological Sciences, Old Dominion University, Norfolk, Virginia 23529-0266, USA;
    6 College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
  • Received:2011-05-10 Online:2011-10-25 Published:2011-06-16
  • Supported by:

    The Chinese Academy of Sciences (KSCX2-YW-Z-0925 & O92441112F), the Ministry of Education of China through its 985 and 111 projects (MUC 98503-001006 & B08044), the National Science Foundation of China (31070288), the Japan Society for the Promotion of Science (JSPS/AP/109080), and the Ministry of Science and Technology of China (2008FY110400-2-2)


Paraisometrum, is a monotypic genus endemic to Southwest China, with an uncertain systematic position. To resolve the phylogenetic relationships of Paraisometrum within subfamily Cyrtandroideae, we performed phylogenetic analyses of 116 taxa placed in the subfamily Cyrtandroideae and 7 outgroup species selected from other Gesneriaceae subfamilies. The independent and combined analyses were performed on three DNA datasets: the nuclear internal transcribed spacer regions (ITS) and two chloroplast regions (trnL-F, atpB-rbcL). Maximum Parsimony (MP) and Bayesian Inference (BI) were used for tree construction. The combined three gene dataset strongly support Paraisometrum in a clade containing Oreocharis, Opithandra, Isometrum, Ancylostemon, and Briggsia rosthomii. In the MP tree this lineage is an unresolved polytomy, but BI resolves Paraisometrum as sister to B.rosthomii and the Ancylostemon clade. We did the first chromosome counts of Paraisometrum (2n=34). The diploid number 34 has also been reported for Oreocharis, Opithandra, Briggsia and Ancylostemon, which lends further support to the placement of Paraisometrum in this lineage.

Key words: atpB-rbcL, Gesneriaceae, ITS, Paraisometrum, Phylogeny, trnL-F

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