Assessment of Genetic Diversity of Coffee Accessions in Rwanda and Its Implication for Coffee Breeding

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.

Organic amendment composition and sowing depth in coffee Arabica: Effects on seedling growth biometrics

“…The finding of this study was in agreement with some research results [ 2 , 5 , [65] , [66] , [67] , [68] , [69] ] who reported that higher number of nodes were observed when coffee seedlings grown using organic amendments possibly due to the availability of rich organic carbon [ [15] , [16] , [17] , [18] , [19] ] that eventually improves growth media porosity, aeration, nutrient uptake and water retention capacity (Adrinal et al, 2021).…”

“…The current findings concur with Teixeira et al [ 65 ], Muvunyi et al [ 66 ], Rodrigues et al [ 67 ] and Netsere and Kufa [ 69 ] who reported that internode lengths of coffee seedlings significantly varied in different plant growth media compositions, probably due to the fertility variation of the organic amendment [ 68 ] and the variation in growing condition [ 64 ]. Besides, DaMatta et al [ 71 ] and Ribeirinho et al [ 50 ] supported that the internode length of coffee seedlings in soil with enough organic matter is longer compared with seedlings grown merely in topsoil.…”

Genetic Analysis of Coffee (Coffea arabica L.) Genotypes in Zimbabwe Using Morphological Traits

“…Unique genes can only come from these divergent cluster families. The existence of both very divergent and uniform genotypes among coffee germplasm was also observed by Muvunyi et al (2017).…”

Plant biotechnology: A key tool to improve crop production in Rwanda

“…In Rwanda, the majority of the agricultural produce is Dusengemungu et al 69 food crops instead of export crops which results in generating low incomes for the farmers (Muvunyi et al, 2017). Primarily due to numerous challenges that result in low crop production including shortage of arable land and mismanagement of available land, inadequate rainfall (climate uncertainties), soil infertility, pest and disease control, limited technology base, to cite a few.…”

“…The practice now is targeting the small-scale farmers and it is hoped to increase productivity, therefore, contributing to the food security and poverty eradication. Choosing the right high productive and reliable breed of cultivated plants is very recommended and should be more exploited by all sectors involved in agriculture (Musoni, 2016;Muvunyi et al, 2017).…”