Abstract:
Temporal variation in allele frequencies in a natural population of wild Vigna unguiculata was studied by making monthly
collections of seeds overatwo-year period. Usingstarch gelelectrophoresis, four outof sevenloci analysed wereshown to be
polymorphic (Enp, Fdh, Fle 3 and Pgd 2). These four loci showed significant variation in allele frequencies over time. Changes
in population structure over time were analysed using F-statistic estimators. Although heterogeneity was evident between
loci, the analysis showed significant differentiation among months within a year for all polymorphic loci. Fixation indexes
wereall positive and statistically different from zero, highlighting asignificant departure from random mating. Using analysis
of variance (ANOVA), the pattern of inbreeding (f) showed significant changes over time (season); among the polymorphic
loci, Enp most strongly contributed to this significance. Significant correlations were found between allele frequencies at
different loci. The monthly average gene diversity (He) and allele frequencies at the Enp locus were found to be significantly
correlatedwithweatherconditions(temperatureandrainfalldistribution).Theseallelefrequencydeviationsovertimecanbe
attributed to changes in pollinator behaviour, and frequent genetic bottlenecks that are associated with changes in
environmental conditions.
