GENETIC DIVERSITY IN SOME LOCAL CASSAVA CULTIVARS IN GHANA

ABSTRACT

The genetic diversity in 100 cassava accessions collected from eight regions of Ghana was assessed using morphological and molecular characterisation. Both qualitative and quantitative morphological traits were used to assess variability in the accessions. Canonical discriminant analysis of morphological data showed that quantitative traits detected more variability than qualitative traits. A set of 1 0 random sequence 1 0 mer oligonucleotide primers selected from among eighty that were screened detected polymorphisms and generated 63 amplified DNA bands. Cluster analysis based on the unweighted paired group method with arithmetic averages (UPGMA) categorised the accessions into eight groups. Some accessions with the same local name were put in the same cluster (Ankra, Bankye boodee, Bosomnsia and Steer bekum driver) and some duplicate accessions from source were clustered into different groups. RAPD markers revealed genetic variability and estimated the genetic distances, which facilitates identification of diverse parents in order to maximise the expression of heterosis. Accession Kav90004 ‘Trailasko’ showed the highest genetic distance of 8 % from Eop8903 ‘Katawire’ and Dmgk05 ‘Bani bisa’ 9% Jaccard similarity coefficient. Eop9802 'Yebesi' and Eop9801 were the most closely related of 87% Jaccard similarity coefficient. Seventeen representative accessions (15%) were selected and kept as core collection for future work. There was no relationship between geographical diversity and genetic diversity.