Cytogenetic studies in the Andropogon gayanus-Andropogon tectorum Complex in Southwestern Nigeria


  • Funmilola Mabel Ojo Department of Biological Sciences (Botany Programme), Olusegun Agagu University of Science and Technology, Okitipupa, Ondo State
  • Chinyere Constance Nwokeocha Natural History Museum, Obafemi Awolowo University, Ile-Ife, Osun State
  • Julius Olaoye Faluyi Department of Botany, Obafemi Awolowo University, Ile-Ife, Osun State



Andropogon gayanus, Andropogon tectorum, Apomixis, Kiwani, Meiotic study


The studies were carried on accessions of the Andropogon gayanus-Andropogon tectorum complex (Poaceae) in southwestern Nigeria to determine the chromosome numbers and meiotic dynamics in the species. This involves meiotic chromosome and pollen studies using standard procedures. Studies on the morphology and meiotic behaviour of collections of A. gayanus (2n = 40) and A. tectorum (2n = 20, 40) have been made. The cytogenetic studies show that the chromosome configuration of A. gayanus is a tetraploid (2n = 40) on a basic chromosome number of 10. A. tectorum occurs as a regular diploid on a chromosome number of 2n = 20 and it is the only species found in Ekiti State. Accession “Kiwani” was found to be a polyploid. A. tectorum with a chromosome number of 2n = 40. This study has also established the stability of the genome of the Andropogon complex. In spite of the occurrence of univalent and multiple associations, meiosis ensures a high percentage of pollen grains. The pollens of accession “Kiwani” (> 35 µm) were generally larger than those of other accessions while the other accessions of both A. gayanus and A. tectorum have modal pollen sizes less than 35 µm, although the A. tectorum accessions were generally smaller. The study concluded that the occurrence of the tetraploid (2n = 40 in accession AT10, “Kiwani” can be attributed to apomixis occurring in a lonely plant.


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Author Biographies

Chinyere Constance Nwokeocha, Natural History Museum, Obafemi Awolowo University, Ile-Ife, Osun State


Natural History Museum,  Obafemi Awolowo University,  Ile-Ife Osun state,  Nigeria

Julius Olaoye Faluyi, Department of Botany, Obafemi Awolowo University, Ile-Ife, Osun State


Department of Botany,  Obafemi Awolowo University, Ile-Ife Osun state Nigeria 


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How to Cite

Ojo, F. M., Nwokeocha, C. C., & Faluyi, J. O. (2023). Cytogenetic studies in the Andropogon gayanus-Andropogon tectorum Complex in Southwestern Nigeria. Caryologia, 76(1), 3–13.