Some measures of gene diversity analysis on land race populations of Ethiopian barley

Abstract

158 land race populations of cultivated barley, represented by 3266 individuals from 19 diverse regions composed of 72 areas, were assayed electrophoretically for 5 enzyme loci (Est-A, Est-B, Est-C, Est-D and Acph-·l) to determine isozyme variability within and among populations. Differences in frequency of isozyme phenotypes were observed among populations within regions and between regions. The number of allozymes detected in the five loci studied were 5 in Est-A, 4 in Est-B, 6 in Est-C, 5 in Est-D and 6 in Acph-·l locus. The supply of alleles varied from region to region, from area to area and from locality to locality. Populations in the same region differed in their allelic composition. The highest number of alleles of the five loci studied detected in a region was 22 and the lowest, 7. A high frequency of null alleles at the Est-B locus was observed in two regions. 44.85% of the total gene diversity was found to be due to genetic variation within localities, 20.13% was due to variation between localities within areas, 18.71% was due to variation between areas within regions, while 16.31% of the total gene diversity was due to genetic variation between regions. The magnitude of the contribution of different components of the hierarchy to the total gene diversity varied from region to region. No correspondence was found between geographical distance and heterozygosity. For the genetic diversity computed Nei's and Gregorius' logics were not found to give a synonymous result. A significant heterogenous distribution of polymorphic events over regions was observed.