Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/1996
Publication Date: N/A
Technical Abstract: Genetic variation at 20 isozyme loci was surveyed from 149 accessions of wild and domesticated Helianthus annuus L. via newly optimized starch gel electrophoretic protocols, yielding one of the more extensive data sets of allelic frequencies available for a crop. This data set was enlisted to resolve several managerial issues regarding H. annuus germplasm. Standard measures of genetic polymorphism were calculated to assess the efficacy of germplasm maintenance procedures. A pair-wise interaccession distance matrix constructed from the data set was analyzed via principal coordinate, UPGMA cluster, and neighbor-joining (NJ) methods. The latter two methods yielded concordant patterns of genetic divergence that were sometimes incongruent with the patterns resulting from UPGMA analyses. The preceding patterns suggested that some accessions were putative wild X domesticated hybrids, that others with identical provenance names were genetically divergent, and that genetic diversity within H. annuus was ecogeographically structured. The utility of isozyme data for delimiting core subsets for the NPGS's H. annuus germplasm collection was assessed.