Advertisement

Journal of Plant Research

, Volume 112, Issue 2, pp 145–161 | Cite as

Chromosomal Evolution in the Genus Brachyscome (Asteraceae, Astereae): Statistical Tests Regarding Correlation Between Changes in Karyotype and Habit Using Phylogenetic Information

  • Kuniaki Watanabe
  • Tetsukazu Yahara
  • Tetsuo Denda
  • Keiko Kosuge

Brachyscome

and 8 taxa of its allied genera, Australian Astereae. Statistical tests regarding correlations between changes in chromosome number, total chromosome length, mean chromosome length, karyotypic asymmetry and chromosome length heterogeneity and changes in habit were performed based on the matK molecular phylogenetic tree. The reductions in chromosome number and total chromosome length, and the increases in mean chromosome length, chromosome length heterogeneity and karyotypic asymmetry were found to be correlated with the change in habit from perennial to annual. A reduction in total chromosome length is favored to shorten the mitotic cell cycle and to produce smaller cells conducive to more rapid development of smaller annuals under the time-limited environment. Stepwise dysploidal reductions in chromosome number were achieved through the translocation of large chromosome segments onto other chromosomes, followed by the loss of a centromere, resulting in one fewer linkage group and one fewer haploid chromosome. The correlations between the dysploidal reduction in chromosome number and the increases in mean chromosome length, length heterogeneity and asymmetry in karyotype can be attributed to this mode of chromosomal change. These changes occurred independently in several different lineages in Brachyscome.

Keywords: Annual, Asteraceae, Brachyscome, Chromosomal evolution, Dysploidy, Semi-desert 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© The Botanical Society of Japan 1999

Authors and Affiliations

  • Kuniaki Watanabe
    • 1
  • Tetsukazu Yahara
    • 2
  • Tetsuo Denda
    • 3
  • Keiko Kosuge
    • 1
  1. 1.Department of Biology, Faculty of Science, Kobe University, 1-2-1 Tsurukabuto, Kobe, 657–8501 JapanJP
  2. 2.Department of Biology, Faculty of Science, Kyushu University, 6-10-1 Hakozaki, Fukuoka, 812–8581 JapanJP
  3. 3.Laboratory of Ecology and Systematics, College of Science, The University of the Ryukyus, Okinawa Pref., 903–8501 JapanJP

Personalised recommendations