STUDIES ON GENE FREQUENCIES OF POLYEMBRYONY AND KARYOTYPE IN FLUTED PUMPKIN (Telfairia occidentalis Hook. F.)
ABSTRACT
Five experiments were performed to investigate the polyembryonic expressions and karyomorphology of fluted pumpkin (Telfairia occidentalis Hook. F.). The results obtained revealed three morphotypes of polyembryony which included twin, triple and quadruple, irrespective of the shape of the pod. The three morphotypes had side shoots that varied in length. Some were  , a few of them were almost equal, and many had rudimentary side shoots, which subsequently degenerated with time. Chi-square test between the pod shape and the embryo type depicted independence (χ2= 1.02; P= 0.90) between pod shape and the embryo type. The triple and quadruple embryo types had the highest and lowest frequencies of occurrence, respectively. The gene frequencies in the first year were 0.64 and 0.36 for polyembryony (S allele) and
monoembryony (s allele), respectively. The derived zygotic frequencies were 0.41 for the homozygous dominant (SS); 0.46 for the heterozygous (Ss) and 0.13 for the homozygous recessive (ss). These summed up to 0.87 for the multiple embryonic traits and 0.13 for the single embryonic trait. In the second year, the zygotic frequencies for the homozygous dominant (SS), the heterozygous (Ss) and the
homozygous recessive (ss) were 0.33, 0.49 and 0.18, respectively.
These corresponded with the 0.82 for the multiple embryonic traits and 0.18 for the single embryonic trait. Chi square analysis showed that the gene frequencies in both years did not differ significantly (χ2= 0.017; P= 0.96). The results obtained from the cytological studies of fluted pumpkin revealed the interphase and mitotic stages of the cell cycle, and a diploid chromosome number of 2n = 22. There were traces of polyploids namely; aneuploids (2n = 22 + 1), triploid.
