Coffea canephora Pierre ex Frohener is a perennial plant originated from Africa. Two main groups, Guinean and Congolese, have already been identified within this species. They correspond to main refugia in western and central Africa. In this paper we present the analysis of a region that has not yet been studied, Uganda. Two wild, one feral (once cultivated but abandoned for many years), and two cultivated populations of C. canephora from Uganda were evaluated using 24 microsatellite markers. Basic diversity, dissimilarity and genetic distances between individuals, genetic differentiation between populations, and structure within populations were analysed. Expected heterozygosity was high for wild compartments (0.48 to 0.54) and for cultivated and feral ones (0.57 to 0.59), with the number of private alleles ranging from 12 for cultivated genotypes to 37 for a wild compartment. The Ugandan samples show significant population structuring. We compared the Ugandan populations with a representative sample of known genetic diversity groups within the species using 18 markers. Coffea canephora of Ugandan origin was found to be genetically different from previously identified diversity groups, implying that it forms another diversity group within the species. Given its large distribution and extremely recent domestication, C. canephora can be used to understand the effect of refugia colonization on genetic diversity.

The amphidiploid Tnfo/ium repens L. (2n = 4x = 32) is one of the most agronomically important of the 250-300 species in the genus Trfolium. Seed production is, however, variable and often poor, because of a number of interacting reproductive and climatic factors. Improvement to those characters influencing seed production may be achieved by interspecific hybridization using a closely related species within the genus. One species which has been demonstrated to have a close affinity with T repens is the annual T nigrescens (2n =2x = 16), a prolific flower producer with a less intermittent pattern of flowering than T repens. Specific cross-combinations of T. repens and C nigrescens readily produced hybrids without the need of embryo culture. Some F1 hybrids produced large numbers of seed when backcrossed to C repens. Chromosome counts, isoenzymes and leaf markers confirmed that these were true hybrids. The F1s and BC1 s were vigorous plants demonstrating intermediate reproductive characters inherited from the two parental species. This novel approach may be a means of extending the range of heritable variation useful in the breeding and selection of T repens.

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This chapter describes the current status of coffee wilt disease (CWD, Gibberella xylarioides) in Uganda, including its occurrence and distribution, its impact on coffee production, the factors affecting its severity and incidence, and country-specific practices for its control.

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Coffea canephora organoleptic cup attributes are the most important factors that define its price in world markets. Determining the components that contribute to the diversity of organoleptic characters will help in the improvement of these qualities in order to obtain favourable markets. Two hundred and six genotypes from twenty one districts and two research institutes were analyzed by a three member expert panel from Uganda Coffee Development Authority using a 10 point descriptive scale and protocols from, The Coffee Quality Institute of America (CQIA). The results revealed that the evaluators" organoleptic cup trait ratings were significantly different (p< 0.05) for all attributes, reflecting a diversity of cup interests. Four multivariate groups that were significantly different for fragrance, aroma and flavour were formed offering diverse cup tests to different markets. A variety of fine and commercial flavours were detected in ripe cherry and green roasted beans. Cup balance contributed the highest regression coefficient (R 2 =0.90) to overall assessment while fragrance/aroma had the least (R 2 =0.22). The above average rating of 75% for cup balance, flavour, mouth feel, aftertaste, fragrance and aroma revealed that Ugandan Robusta coffees were of high quality with a mild taste. The higher cup acidity among land races,"nganda" and ISSN 2166-0379 2016 www.macrothink.org/jas 102 "erecta" genotypes revealed that genotypes with high sugars and cup acidity could be selected for from local germ-plasm. Coffee types and environmental factors such as soil texture, altitude and location influenced the content and level of organoleptic cup attributes. A diversity of flavours that exist among Uganda Robusta coffee and has so far remained unexploited, would provide new marketing channels, enhance quality and earn the country the much desired foreign exchange capital. Journal of Agricultural Studies

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