Department of Biological Sciences, Ahmadu Bello University, Zaria, Nigeria
Online published on 25 January, 2012.
The haploid number of chromosomes in two West African S. melongena vars., Giwa-1 and Giwa-2, was found to be 12. Chromosome aberrations were observed in pollen mother cells, generally in form of chromatid bridges, fragments, lagging and elimination of univalents. The frequency of these aberrations has been determined.
The association of chromosomes in threes and fours occurred in 16.2% and 15.2% pmc. in vars. Giwa-1 and Giwa-2 respectively. The occurrence of high frequency of polyvalents in diploid West African eggplants seemed to indicate the presence of translocation interchanges.
The frequency of univalents in Giwa-1 and Giwa-2 was 22.9% and 18.1%. Structural changes and gene mutation are probably responsible for failure of pairing among pairable chromosomes. The behaviour of univalents varied, they either pass to poles or lag or divide. The division and elimination of univalents causes unequal distribution of chromosomes on second metaphase plates. The univalents and fraagments which failed to be included in the daughter nuclei formed micronuclei, resulting in considerable abortion of pollen grains (22.5% and 41.8% in Giwa-1 and Giwa-2, respectively).
These chromosome aberrations are presumably due to gene mutation which may have been enhanced by hybrid genotypic constitution.
