Genetic diversity in Tanzanian Arabica coffee using random amplified polymorphic DNA (RAPD) markers

DNA from Coffea arabica leaves was used for RAPD analysis and a total of 144 leaf samples collected from 16 provenances in five regions of Tanzania were analysed. Ten arbitrary 10 mer primers were employed in the analysis and they produced a total of 86 fragments. Fragment sizes ranged from 100-1400 bp. The resulting dissimilarity matrix revealed values ranging from 0.11 to 1, while the average was 0.66. The cophenetic matrix and the original dissimilarity matrix showed a significant correlation of 78%. Mean dissimilarity values within provenances showed a fairly uniform trend despite the large range from 0.31 to 0.65. The dendrogram based on genetic distances showed two clusters with grouping of provenances similar to the dendrogram generated by Jaccard's coefficient. Bootstrap analysis showed low values, but despite this, the resulting dendrogram grouped all provenances according to their geographical origin. The standard genetic distances were fairly uniform implying a narrow genetic base in the cultivated Arabica coffee.