Journal of Plant Research

, Volume 120, Issue 5, pp 585–593

Identification of parental genomes and genomic organization in Aster microcephalus var. ovatus

Regular Paper

DOI: 10.1007/s10265-007-0101-4

Cite this article as:
Matoba, H., Soejima, A. & Hoshi, Y. J Plant Res (2007) 120: 585. doi:10.1007/s10265-007-0101-4

Abstract

The karyotype of diploid Aster iinumae is morphologically similar to that of diploid Aster ageratoides var. ageratoides, however, its chromosome size is apparently smaller (S-type chromosomes versus L-type chromosomes, respectively). The hybrid origin of tetraploid Aster microcephalus var. ovatus (LS-type chromosomes) has previously been suggested by cytogenetics and chloroplast DNA (cp DNA) data. The cp DNA phylogeny also implies that the S-type chromosome is apomorphic, which means that genome size reduction occurred on the evolutionary way to A. iinumae. In this study, we have demonstrated that the chromosome size difference does not depend on the intensity of chromosome condensation but on the DNA content. The simultaneous genomic in situ hybridization (GISH) results show the similarity between S-type chromosomes of A. iinumae and A. microcephalus var. ovatus, and between L-type chromosomes of A. ageratoides and A. microcephalus var. ovatus, which provide additional evidence for A. microcephalus var. ovatus being a tetraploid amphidiploid produced by hybridization between S-type chromosomes and L-type chromosomes. The distribution patterns of Ty1-copia-like retrotransposons were similar in L- and S-type chromosomes. The copies of this retrotransposon dispersed uniformly on all chromosomes, and it is not yet apparent how the Ty1-copia-like retrotransposon affects the size difference between them.

Keywords

Aster Alloploidy Genome size reduction GISH Ty1-copia-like retrotransposon Speciation 

Copyright information

© The Botanical Society of Japan and Springer 2007

Authors and Affiliations

  • Hideyuki Matoba
    • 1
  • Akiko Soejima
    • 2
  • Yoshikazu Hoshi
    • 3
  1. 1.Department of Applied Biological ScienceCollege of Bioresource Sciences, Nihon UniversityFujisawaJapan
  2. 2.School of Science, Osaka Prefecture UniversitySakaiJapan
  3. 3.Department of Plant ScienceKyushu Tokai UniversityKumamotoJapan

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