Chromosome Research

, Volume 14, Issue 6, pp 665–672

Genome size, karyotype, meiosis and a novel extra chromosome in Torenia fournieri, T. baillonii and their hybrid

  • S. Kikuchi
  • H. Tanaka
  • T. Shiba
  • M. Mii
  • H. Tsujimoto
Article

DOI: 10.1007/s10577-006-1077-y

Cite this article as:
Kikuchi, S., Tanaka, H., Shiba, T. et al. Chromosome Res (2006) 14: 665. doi:10.1007/s10577-006-1077-y

Abstract

Torenia is a suitable model plant to study plant fertilization because of its protruding embryo sac. However, information on the genomes and chromosomes of this species is limited. We determined the genome sizes of T. fournieri Linden and T. baillonii Godefr as 1.71 pg × 108 bp and 1.67 × 108 bp, respectively. The small genome size of these species suggests their superiority as the targets for molecular cloning studies. Furthermore, karyotypes of T. fournieri and T. baillonii were determined using FISH probed with 5S rDNA, 45S rDNA and species-specific centromere repetitive sequences. Although the two species have similar genome size, number of chromosomes, centromere repeats and 5S rDNA loci were varied. Observation of meiosis in the F1 hybrid revealed that all chromosomes except one of T. fournieri paired well with the chromosomes of T. baillonii throughout the entire length of the chromosomes including species-specific centromeric regions. One exceptional chromosome of T. fournieri behaved as a univalent and was not always required for gametogenesis. The present results provide the basis for the molecular genetics in Torenia.

Key words

chromosome pairing extra chromosome genome size karyotype Torenia 

Copyright information

© Springer 2006

Authors and Affiliations

  • S. Kikuchi
    • 1
  • H. Tanaka
    • 1
  • T. Shiba
    • 2
    • 3
  • M. Mii
    • 2
  • H. Tsujimoto
    • 1
  1. 1.Laboratory of Plant Genetics and Breeding Science, Faculty of AgricultureTottori UniversityTottoriJapan
  2. 2.Plant Cell Technology Laboratory, Faculty of HorticultureChiba UniversityChibaJapan
  3. 3.Plant Biotechnology DepartmentNational Institute of Agrobiological Sciences (NIAS)TsukubaJapan

Personalised recommendations