Objective  Diversity on the agronomic traits relating to breeding purpose of arabica coffee germplasms in collection was studied.

  Method  From 60 arabica coffee germplasms, 8 agronomic and 5 quality traits were targeted and subjected them to the correlation, principal component, and cluster analyses for the genetic diversity study.

  Result  Among the 8 agronomic traits, the fresh/dry ratio had the highest coefficient of variation of 25.15% followed by fresh fruit weight of 19.85%, while green bean rate of 1.97% being the lowest. Seed length ranked the highest on the genetic diversity indices. On the 5 quality traits, the chlorogenic acid content showed the highest coefficient of variation of 22.68% followed by fat of 12.40%, and protein of 5.20% being the lowest of all. Chlorogenic acid also had the greatest genetic diversity index of 2.07 followed by fat of 2.06 and protein of 2.05. The dry bean weight of the germplasms significantly correlated with their green bean rate; the seed size with 100-seed weight, green bean rate and protein; the 100-seed weight with green bean rate, protein and fat; and, the green bean rate with protein and fat. The contents of protein and fat showed an extremely significant correlation; whereas, those of caffeine and sucrose an extremely significant inverse correlation. The principal component analysis indicated the top 4 main components (i.e., PC1-PC4) included the 12 agronomic traits and had a combined contribution of 69.17% of the total constituting the major factors that affected the diversity. A cluster analysis classified the 60 germplasms into two groups, 53 in Group I and 7 in Group II. Group II was high on the fresh fruit weight, especially, Subgroup II-2, which exhibited high fresh and dry bean weights.

  Conclusion  The arabica coffee germplasms under study were rich in diversity. The desirable genes could be preserved by domestication, hybridization, grafting and/or molecular breeding. Subgroup II-2, being high on fresh and dry bean weights, could conceivably be used as a parent for new variety breeding.