Geoffrey Tusiime

Makerere University · Department of Agricultural Production

Soybean (Glycine max) is a vital crop for food, animal feed, and industrial products. However, its yield performance is significantly affected by genotype-by-environment interaction (GEI), which complicates the selection of high-yielding, stable varieties. This study aimed to evaluate the yield performance and stability of 12 elite soybean varietie...

Rice (Oryza sativa) bacterial blight (BB) is a direct threat to production in Africa. The extent of damage on the continent is not known. We conducted a genome-wide association study (GWAS) to seek out Quantitative trait loci (QTL) that confer the broad-spectrum resistance (BSR) to rice Xanthomonas oryzae pv. oryzae in the rice Multiparent advanced...

Background: Xanthomonas oryzae pv. Oryzae (Xoo), the causal agent of rice bacterial blight disease has been extensively characterized and loci against different races identified. Many rice cultivars have been developed and utilized to combat the disease, however due to rapid evolution of Xoo, a number of resistances have broken-down. The continuous...

Soybean is a high oil and protein-rich legume with several production constraints. Globally, several fungi, viruses, nematodes, and bacteria cause significant yield losses in soybean. Coniothyrium glycines (CG), the causal pathogen for red leaf blotch disease, is the least researched and causes severe damage to soybean. The identification of resist...

Soybean (Glycine max L.) is an important oil crop with production below the real need in Africa. To increase production, substantial upgrading must be accomplished by enlarging the genetic potential of new cultivars that relies on the parents’ genetic diversity. We aimed to assess the genetic diversity and the population structure of soybean access...

Background Xanthomonas oryzae pv. Oryzae (Xoo), the causal agent of rice bacterial blight disease has been extensively characterized and loci against different races identified. Many rice cultivars have been developed and utilized to combat the disease, however due to rapid evolution of Xoo, a number of resistances have broken-down. The continuous...

Background: Xanthomonas oryzae pv. Oryzae (Xoo), the causal agent of rice bacterial blight disease has been extensively characterized and loci against different races identified. Many rice cultivars have been developed and utilized to combat the disease, however due to rapid evolution of Xoo, a number of resistances have broken-down. The continuous...

Soybean ( Glycine max (L.) is an important oil crop with production below the real need in Africa. To increase the production, substantial upgrading must be accomplished by enlarging the genetic potential of new cultivars that relays on the parents' genetic diversity. We aimed to assess the genetic diversity and the population structure of soybean...

Soybean ( Glycine max (L.) is an important oil crop with production below the real need in Africa. To increase the production, substantial upgrading must be accomplished by enlarging the genetic potential of new cultivars that relays on the parents' genetic diversity. We aimed to assess the genetic diversity and the population structure of soybean...

The yield and protein performance in a soybean genotype result from its interaction with the prevailing environmental conditions. This makes selecting the best genotypes under varied target production environments more complex. This study’s objectives were to determine protein content and protein stability of 30 elite soybean genotypes in major soy...

Bacterial leaf streak disease (BLS) caused by Xanthomonas oryzae pv oryzicola is one of the emergent biotic constraints to rice production in Africa. The disease, which can cause yield loss of up to 60% on susceptible cultivars, was observed in Uganda in the rice growing districts of Namutumba, Butaleja and Iganga in 2014. As such there is limited...

Rice blast disease remains the most important contributor to low and stagnated rice yields in Uganda. However, the role of the smallholder farming system in shaping the prevalence of the disease in the country is not known. In 2015B and 2016A, we surveyed smallholder rice farmlands in 27 districts of Uganda and recorded blast incidence, severity, a...

Differential yield response of a genotype is the result of its interaction with the prevailing environment. This makes the task of selecting widely adapted and best soybean genotypes challenging under varied target production environments. The objectives of this study were to; (i) determine the mean performance and stability of 30 elite soybean gen...

Breeding for resistance is a major component in the integrated management of common bacterial disease of beans (Phaseolus vulgaris L.). Use of less virulent strains or strains with attenuated virulence may lead to selection of resistant genotypes with intermediate response, when exposed to more virulent strains of the pathogen. The objective of thi...

Kumi F, Badji A, Mwila N, Odong T, Ochwo-Ssemakula M, Tusiime G, Gibson P, Biruma M, Prom KL, Cuevas HE, Agbahoungba S, Rubaihayo P. 2019. New sources of sorghum resistant genotypes to downy mildew disease in Uganda. Biodiversitas 20: 3391-3397. Sorghum downy mildew (SDM) disease is still prevalent in Uganda at varying levels of incidence and sever...

Though Uganda produces adequate amounts of food for its population the nutritional status is generally poor and undernourishment is considered as one of the major health problems. Despite the high prevalence of malnutrition, there is no literature that clearly documents the Uganda national food composition. The objective of this study was to identi...

Banana, a major staple in East and Central Africa is constrained by banana Xanthomonas wilt (BXW) caused by Xanthomonas campestris pv. musacearum (Xcm). Xcm-infected plants are rapidly destroyed leading to 100% yield loss. Cultural controls are effective but laborious attracting laxity among farmers. This has led to epidemic resurgence in areas whe...

Common bacterial blight (CBB) is associated with common bean (Phaseolus vulgaris L.), an important grain legume for human consumption worldwide. The disease, caused by Xanthomonas spp. is spread mainly through seed. This paper focuses on the diversity of X. axonopodis pv. phaseoli and X. fuscans subsp. fuscans and interactions between related bacte...

Stability in performance is important for determining adaptation and recommendation of pre-commercial crop varieties. This study was conducted with the following objectives: i) to determine stability of grain yield for 55 quality protein maize (QPM) single cross hybrids generated from 14 inbred lines ii) to determine the pattern of grouping of QPM...

Pineapple (Ananas comosus L. Merr) is an economic horticultural crop in Uganda. However, pineapple production is currently being threatened by the latest outbreak of pineapple heart rot disease in Uganda. Yet, information on pineapple heart rot disease causal pathogen is unknown. Therefore, the objective of this study was to identify the pathogen c...

Sorghum (Sorghum bicolor) ranks as the third most important staple cereal food crop in Uganda after maize and millet. The crop is hampered by several biotic stresses of which Sorghum Downy Mildew disease is one of the most devastating diseases. The disease is caused by a soil-borne fungus Peronosclerospora sorghi but it is also air-borne through co...

Bean anthracnose caused by the fungus Colletotrichum lindemuthianum is among the most destructive diseases of common bean in Uganda, Brazil and worldwide, especially in the high altitude and low temperature areas. This study was conducted to identify sources of effective resistance for use in bean breeding program in both Uganda and Brazil. Through...

Pseudocercospora fijiensis, causal agent of the black Sigatoka disease (BSD) of Musa spp., has spread globally since its discovery in Fiji 1963 to all the banana and plantain growing areas across the globe. It is becoming the most damaging and economically important disease of this crop. The identification and characterization of genes that regulat...

Pineapple heart rot disease (PHRD) caused by Phytophthora nicotianae is a threat to pineapple industry in Uganda. Currently, there is uncertainty in the management of the disease. Elsewhere, fungicides are used for management of Phytophthora diseases. The objective of this study was to determine in vitro efficacy of fungicides for the control of Ph...

Sorghum is the third most important staple cereal crop in Uganda after maize and millet. Downy mildew disease is one of the most devastating fungal diseases which limits the production and productivity of the crop. The disease is caused by an obligate fungus, Peronosclerospora sorghi (Weston & Uppal) with varying symptoms. Information on the geneti...

Pineapple (Ananas comosus L. Merrill) is one of the most important horticultural crops in many tropical and subtropical countries including Uganda. Currently, pineapple production in Uganda is being threatened by the outbreak of Pineapple heart rot disease (PHRD). Information on the pathogenicity of the causal organisms in Uganda is still scanty. T...

Germplasm of common beans from the Mesoamerican gene pool races: Durango, Jalisco, Mesoamerica and Guatemala have highest genetic variation for the crop's improvement. The objective was to assign 50 common bean germplasm in Uganda into its gene pool races based on analyses of population structure. Secondly, to estimate heritability and effects of g...

Fusarium related root rots have been associated with reduced cowpea productivity in Uganda. Sources of genetic resistance to Fusarium redolens which was found to be the most virulent have been identified but the mode of inheritance of the genes conferring the resistance is unknown. This study aims to investigate how the genes for resistance to F. r...

Black Sigatoka disease, caused by Pseudocercospora fijiensis is a serious constraint to banana production worldwide. The disease continues to spread in new ecological niches and there is an urgent need to develop strategies for its control. The high osmolarity glycerol (HOG) pathway in Saccharomyces cerevisiae is well known to respond to changes in...

Root rots (RR) are the main cause of declining bean (Phaseolus vulgaris) production in southwestern Uganda. Here, beans are mainly intercropped/rotated with maize (Zea mays), sorghum (Sorghum bicolor), sweet potato (Ipomoea batatas), potatoes (Solanum tuberosum) and garden peas (Pisum sativum). These crops also suffer from RR and bean RR pathogens...

Common bean production is constrained by different diseases the major ones being, Angular Leaf Spot (ALS), bean root rot, anthracnose, Common Bright Bacteria (CBB), Bean Common Cosaic Virus (BCMV) and Bean Common Mosaic Necrotic Virus, (BCMNV). The aim of this study was to identify new and better sources of broad resistance to both bean ALS and Roo...

Angular leaf spot (ALS) is one of the most economically important bean diseases in Africa. One promising control option for the disease is the use of mixtures of resistant and susceptible varieties. This research evaluated (1) the reaction of farmer preferred bean varieties to ALS in the screenhouse and on-station and (2) the effect of different sp...

This article was inspired by a dialogue that transpired during the 5th All Africa Higher Education Week and Biennial Conference of the Regional Universities Forum for Capacity Building in Agriculture (RUFORUM), held in October 2016. The conference gathered over 850 participants from 72 countries and is usually a convening event that brings together...

Potato production in Uganda is being affected by rainfall fluctuations in both timing and amount, resulting into inadequate soil moisture availability and low productivity. Also, potato production is expanding into locations at lower altitudes, where drought is more common. Therefore, drought stress mitigation measures and coping mechanisms need to...

Insects are a major mode of banana Xanthomonas wilt (XW) spread. High insect activity has been blamed for the high XW incidence in 'Kayinja' (ABB-genome) dominated banana landscapes across east and central Africa. 'Kayinja' male bud nectar composition reportedly contributes to high insect activity. The variation in nectar composition with agro-ecol...

Abstract Potato is an important staple food and source of income in the highlands of Uganda. However, its production is being affected by precipitation fluctuations in both timing and amount, resulting into inadequate soil moisture availability and low productivity. Many regions in the world that previously had stable and reliable rainfall pattern...

Insect vectors of Xanthomonas campestris pv musacearum (Xcm) have played a major role in long distance and plant to plant transmission of Xanthomonas wilt of banana (XW). The prevalence of insects has been reported to vary in space and time. Some banana cultivars have also been reported to attract more insect vectors of Xcm than others. The present...

Phytopthora infestans (Mont.) de Bary the pathogen responsible for causing late blight in potato and tomato is a rapidly evolving and highly adaptable pathogen. Following the appearance of a new clonal genotype in Kenya (KE-1 lineage) in 2007, there was a need to document possible displacement of the older US-1 genotype by the newer lineage. Sample...

Common bean is the most consumed pulse globally and a very important crop in tropical Africa, especially in the Central, East and southern Africa, both for its nutritional value and its market potential. Unfortunately, genotype by environment interactions has an important effect on the breeding of better varieties for beans nutritional traits espec...

Micronutrient malnutrition especially iron (Fe) and zinc (Zn) has disastrous consequences for the more vulnerable members of the human society, especially poor women and preschool children in developing countries. The common bean (Phaseolus vulgaris L.), an important grain legume directly consumed by humans provides cheap and important quantities o...

Farmers have shown preference for the maize variety Longe 5 because of its quality protein nature, easy access to seed and high adaptability. However production of Longe 5 is constrained by endemic foliar diseases including turcicum leaf blight. The current study determined the effectiveness of two cycles of S 1 recurrent selection towards improvem...

Background Production of cassava (Manihot esculenta Crantz), a food security crop in sub-Saharan Africa, is threatened by the spread of cassava brown streak disease (CBSD) which manifests in part as a corky necrosis in the storage root. It is caused by either of two virus species, Cass ava brown streak virus (CBSV) and Ugandan cassava brown streak...

Thirteen promising clones from population B3C2 potato genotypes (bred for quantitative resistance to late blight) obtained from the International Potato Center and three control cultivars were evaluated for four planting dates within two cropping seasons at Kalengyere Research Station in Southwestern Uganda in order to determine performance and yie...

There has been much emphasis on breeding for increased sweetpotato storage root yield, but less on dry matter yield, and its inheritance. High dry matter content (DMC) is associated with consumer preferences, and is important for the processing industry. This study was conducted to determine the type of gene action controlling DMC and to assess gen...

Abstract A study was implemented in six locations in 2010 to establish the reaction of MT56, an introduced tomato cultivar showing potential resistance in research trials, to Ralstonia solanacearum across agroecological zones in Uganda. In a randomized complete block design, MT56 vs. three susceptible (Marglobe, Moneymaker and Roma) and one resista...

Background: A key challenge for designing RNAi-based crop protection strategies is the identification of effective target genes in the pathogenic organism. In this study, in vitro antifungal activities of a set of synthetic double-stranded RNA molecules on spore germination of two major pathogenic fungi of banana, Fusarium oxysporum Schlecht f. sp...

Banana Xanthomonas wilt (BXW) caused by Xanthomonas campestris pv. musacearum (Xcm) is a devastating disease of bananas in Uganda and across the Great Lakes region of East and Central Africa. While use of disease-free suckers is recognized as important to control BXW, bacterial movement from infected mother plants to their suckers is not well under...

Pgt race TTKSK (Ug99) has a wide virulence range with respect to currently grown wheat cultivars worldwide. Aspects of migration, mutation, recombination and selection in the pathogen have led to previously deployed stem rust resistance genes being ineffective. Race TTKSK has further evolved to acquire virulence for resistance genes such as Sr24 (r...

The main areas for cowpea cultivation in Uganda were surveyed in June and October 2006 for viruses affecting the crop. Seed and leaf samples from symptomatic and asymptomatic plants were collected from farmers' fields and analysed for infecting viruses using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The viruses detecte...

Atim, M., Beed, F., Tusiime, G., Tripathi, L., and van Asten. P. 2013. High potassium, calcium, and nitrogen application reduce susceptibility to banana Xanthomonas wilt caused by Xanthomonas campestris pv. musacearum. Plant Dis. 97:123-130. The effect of exogenous applications of potassium (K), calcium (Ca), and nitrogen (N) on the susceptibility...

In the present study, we assessed the pathogenicity of the prevalent strains of Rice Yellow Mottle Virus (RYMV) present in Eastern Uganda and identified suitable donors for durable resistance among rice cultivars. Screenhouse studies were conducted using eight isolates of the virus against 16 rice cultivars. Isolate aggressiveness and cultivar resi...

A specific and rapid diagnostic tool has been developed to detect Xanthomonas campestris pv. musacearum, the causal agent of bacterial wilt of banana. PCR primers were developed from intergenic regions of X. campestris pv. musacearum following its partial sequence. A total of 48 primers were tested for specificity to X. campestris pv. musacearum st...

Plant parasitic nematodes remain a major challenge to crop production that has hitherto received minmum research attention in sub-Saharan Africa. This paper gives the diversity of nematode genera and species associated with cereal crops and indicates the possibility of nemadode population build up due to production intensification especially in soi...