Abstract:
Information on genetic variability is a prerequisite for further improvement of the yield and quality of coffee.
However, lack of information on genetic variability for specialty coffee accessions has been one of the major
problems in coffee improvement program. Forty nine coffee (Coffea arabica L.) germplasm accessions, which
were collected from Gomma Wereda, were evaluated at Agaro research station with the objective of estimating
the genetic diversity. The experiment was conducted in simple lattice design with two replications during
2011/12 cropping season by superimposing on six years old coffee trees which were planted in July, 2006 and
grown under uniform coffee shade tree (Sesbania sesban) conditions. Data on 26 quantitative characters were
recorded. The analysis of variance showed significant (P<0.05) variation among the accessions for all
morphological traits except percentage bearing primary branches, leaf area, bean thickness and rust incidence.
This indicated the existence of variability among the tested materials. Cluster analysis of quantitative
characters grouped the 49 coffee germplasm accessions into five clusters. This makes the germplasm
accessions to be moderately divergent. The distances between most of these clusters were highly significant at
(P<0.01), suggesting the possibility of getting suitable accessions for hybridization program among the tested
materials. Principal component analysis showed the variation in the first two principal components, which
explained the lion’s share of the observed variation, (42%), was mainly due to inter node length of main stem
and primary branches, leaf length, hundred bean weight, plant height, number of main stem nodes, number of
primary branches, length of primary branches, number of secondary branches and canopy diameter. So, these
traits were identified as a source variation among Gomma wereda coffee accessions and can be used for
selecting diverse parents in future coffee hybridization program.
