Assessment of genetic diversity in a collection of Ghanaian okra germplasm (abelmoschus spp l.) using morphological markers.
A total of 25 accessions of okra collected in Ghana were evaluated for phenotypic identity, diversity and quality based on morphological characterisation. Nineteen quantitative and seventeen qualitative characters were measured on the genotypes in field experiments using randomized complete block design with four replications, and phenotypic characters scored as specified by the standard international crop descriptor for okra (IBPGR, 1991). A dendrogram (cluster diagram) was generated for morphological data based on the Simple Matching Coefficient and four cluster groups were observed. The distribution of the accessions into the groups, based on the morphological traits had no unique geographical relationship. The results of the matrix of similarity among the 25 accessions performed using the NTsys pc programme placed two accessions in a tie, suggesting they were identical. Eight (8) accessions were placed at over 80% similarity, meaning the accession pairs were closely related, and three accessions were 50% similar, which means they matched at half the characters neasured. Six pairs of accessions measured were somewhat diverse, which can be exploited by plant breeders for further improvement. The genetic affinity between the accessions from different regions and ethnic groups could however be due to the selection and exchange of okra between farmers from different regions and ethnic groups. This shows that similar names might not suggest a means for identifying duplicates in the okra germplasm. Further research at the molecular level will be required to confirm duplicate accessions to enhance this work.
A thesis submitted in partial fulfillment of the requirements for the award of a Master of Science degree in Crop Science, Agronomy (Plant Breeding) at the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.