Abstract:
Twenty coffee genotypes were characterized comprising of eleven F1 interspecific Arabusta hybrids,
three induced tetraploid Robusta parental genotypes, four Arabica parental genotypes, one diploid
Robusta accession and one Hybrido de Timor (HDT), a natural interspecific hybrid between
Arabica and Robusta. Characterization was conducted using thirteen Simple Sequence Repeats
(SSR) and ten Random Amplified Polymorphic DNA (RAPD) molecular markers. The molecular
data were analyzed for polymorphism and also subjected to cluster analysis using Unweighted Pair
Group Method with Arithmetic Average (UPGMA) to estimate the diversity among the genotypes.
SSR markers revealed a genetic diversity of 51.5%, 50% and 6.9% while RAPD markers revealed
genetic diversity of 51.6%, 47.4% and 3.5% within induced tetraploid Robusta, F1 interspecific
Arabusta hybrids and Arabica genotypes respectively. The SSR primers separated the genotypes
into 3 distinct clusters unlike RAPDs which separated them into 7 distinct clusters. The study
therefore confirmed the narrow genetic base within Arabica coffee and successfully portrayed the
possibility of broadening it through interspecific hybridization. These results can be used to select
parents with high combining ability in a hybridization program between Arabica and tetraploid
Robusta.
