African Journal of
Plant Science

  • Abbreviation: Afr. J. Plant Sci.
  • Language: English
  • ISSN: 1996-0824
  • DOI: 10.5897/AJPS
  • Start Year: 2007
  • Published Articles: 806

Full Length Research Paper

Chromosome numbers and karyotype in three species of the genus Vernonia Schreber in Southern Nigerian

Kemka-Evans, C. I.1* and Okoli, Bosa2
1Alvan Ikoku Federal College of Education Owerri, Imo State, Nigeria. 2Regional Centre for Bioresources and Biotechnology, Rivers State, Nigeria.
Email: [email protected]

  •  Accepted: 26 August 2013
  •  Published: 30 November 2013


Detailed cytological studies were carried out on three species of the genus Vernonianamely Vernonia amygdalina (bitter leaf and non-bitter leaf), Vernonia cinerea andVernonia conferta to ascertain their chromosome number. The taxa studied showed diploid number of chromosome for V. cinerea (2n = 18) and V. conferta (2n = 20) and tetraploid number for V. amygdalina (2n = 36). The karyotype show nine (9) pairs of submetacentric chromosomes in V. cinerea and 10 pairs of submetacentric chromosomes in V. conferta. The karyotype of V. amygdalina (bitter leaf) varied from that of V. amygalina (non-bitter) by being larger in size and with a pair of telocentric chromosome. The studies of the pollen fertility suggest that V. amygdalina is an amphidiploid.


Key words: Chromosome numbers, karyotype, polyploidy, Vernonia.