Journal of Plant Research

, Volume 115, Issue 3, pp 0225–0235 | Cite as

Karyomorphology of Taiwanese Begonia (Begoniaceae): taxonomic implications

  • K. Oginuma
  • C.-I Peng
ORIGINAL ARTICLE

Abstract

 The karyomorphology of all 14 species of Taiwanese Begonia was investigated to elucidate their chromosome features and chromosomal evolution. Among all species investigated, differences in chromosome features are found in: (1) chromosome number 2n = 22, 26, 36, 38, 52, 60, 64, 82, and (2) frequencies of chromosomes with secondary, tertiary, and/or small constrictions of polyploids, ranging from 23% to 63%, which is higher than the expected value of about 9%. It is suggested that after polyploidization from the diploid species (i.e., 2n = 22 and frequencies of chromosomes with secondary, tertiary, and/or small constrictions of polyploids of about 9%), chromosome translocations occurred, followed by a decrease in chromosome number, and subsequently stabilized genomes were formed in various species in Taiwan. The karyomorphological evidence also suggested that the chromosome morphology has evolved in parallel in the begonias belonging to different sections in Taiwan. The variation in chromosomal features is more complex than the variation in floral and fruit morphologies. Karyomorphological data also supports the recognition of five new species in Taiwan: Begonia bouffordii, B. chuyunshanensis, B. pinglinensis, B. tengchiana, and B. wutaiana. Based on detailed karyomorphological analyses, the taxonomic implications, speciation, and chromosomal evolution in Taiwanese Begonia are discussed.

Key words Begonia Begoniaceae Chromosome cytology Karyomorphology Taiwan 

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Copyright information

© The Botanical Society of Japan and Springer-Verlag Tokyo 2002

Authors and Affiliations

  • K. Oginuma
    • 1
  • C.-I Peng
    • 2
  1. 1.Faculty of Human Life and Environmental Science, Kochi Women's University, Kochi, JapanJP
  2. 2.Institute of Botany, Academia Sinica, Taipei, Taiwan Tel. +886-2-2789-9590 ext 404/406; Fax +886-2-2789-1623 e-mail: bopeng@sinica.edu.twTW

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