TITLE:
Assessment of Genetic Diversity of Coffee Accessions in Rwanda and Its Implication for Coffee Breeding
AUTHORS:
B. P. Muvunyi, P. Y. K. Sallah, L. Dusengemungu, Jiyu Zhang
KEYWORDS:
Coffee, Genetic Diversity, Morphological Markers, Breeding, Rwanda
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.10,
September
18,
2017
ABSTRACT: Genetic variation is important in breeding programs because it determines
the amount of gain from selection. This
study was conducted to determine the magnitude of genetic diversity in
coffee (Coffea Arabica L.) accessions for developing superior cultivars in Rwanda. Twenty-one
coffee accessions established in 1990 in an un-replicated field experiment at the Rubona
Experimental Station of the Rwanda Agriculture Board (RAB) located in the
mid-altitude zone of Rwanda, were used in the study. Data were recorded on three randomly selected trees on eight quantitative morphological
traits in each accession in 2013.
One-way analysis of variance (ANOVA) indicated highly significant (p 0.01)
differences among the accessions for number of primary branches, number of
leaves per branch, number of cherries per internode and % coffee leaf rust disease rating; and significant (p 0.05) for yield, but not for internode length, weight of 100 cherries, and number of internodes per branch.
Multivariate analysis showed that the first three principal components
contributed cumulatively to 78.3% of the total variation. The PCA biplot
grouped all the accessions into three different clusters and one singleton. The
first and second PCs accounted for 43% and
21%, respectively. Cluster I and II grouped accessions with valuable
quantitative agronomic traits while accessions in cluster III exhibited poor
agronomic performance. The highest inter cluster distance of 475 was observed
between cluster I and II, and the highest intra-cluster distance (62) was in
cluster II. The phenotypic markers provided a useful measure of genetic
distances among the coffee accessions and identified potential donors for
future breeding efforts.