Browsing by Author "Onyilo, Francis"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Agricultural Cooperative marketing and credit policy reform in Uganda: An opportunity for poverty reduction
    (African Journal of Food, Agriculture, Nutrition and Development, 2019) Onyilo, Francis; Adong, Annet
    Academics and development practitioners increasingly view cooperatives as the cornerstone for agricultural transformation and poverty reduction in sub-Saharan Africa. Cooperatives play a crucial role in promoting bulk storage and sale by smallholder farmers, which can play a major role in poverty reduction for farmers otherwise unable to commercialize. Despite the significant role of cooperatives, the reforms associated with economic liberalisation have caused many cooperatives in the region to fail. While efforts were made in Uganda to ameliorate this situation through the passing of the National Co-operative Policy (NCP), this has done little to enhance the survival of these cooperatives. In this opinion paper, we identify challenges faced by cooperatives that negatively impact performance and survival, such political interference, lack of administrative support, human resource constraints, inadequate knowledge of the operations by members and poor governance. This paper recommends stronger linkages between the Ministry of Trade, Industry and Cooperatives and the Ministry of Agriculture Animal Industry and Fisheries (MAAIF). Integrating cooperatives into the decentralisation framework and formalising existing village savings and loan association groups into formal cooperatives. Most importantly, the government needs to take on a more proactive approach toward cooperative development, as seen in some countries such as South Africa and Rwanda.
  • Thumbnail Image
    Item
    Agrobacterium tumefaciens-mediated transformation of pseudocercospora fijiensis to determine the role of PfHog1 in osmotic stress regulation and virulence modulation
    (Frontiers in Microbiology, 2017) Onyilo, Francis; Tusiime, Geoffrey; Chen, Li-Hung; Falk, Bryce; Stergiopoulos, Ioannis; Tripathi, N. Jaindra; Tushemereirwe, Wilberforce; Kubiriba, Jerome; Changa, Charles; Tripathi, Leena
    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 external osmolarity. HOG pathway activation leads to phosphorylation, activation and nuclear transduction of the HOG1 mitogen-activated protein kinases (MAPKs). The activated HOG1 triggers several responses to osmotic stress, including up or down regulation of different genes, regulation of protein translation, adjustments to cell cycle progression and synthesis of osmolyte glycerol. This study investigated the role of the MAPK-encoding PfHog1 gene on osmotic stress adaptation and virulence of P. fijiensis. RNA interference-mediated gene silencing of PfHog1 significantly suppressed growth of P. fijiensis on potato dextrose agar media supplemented with 1 M NaCl, indicating that PfHog1 regulates osmotic stress. In addition, virulence of the PfHog1-silenced mutants of P. fijiensis on banana was significantly reduced, as observed from the low rates of necrosis and disease development on the infected leaves. Staining with lacto phenol cotton blue further confirmed the impaired mycelial growth of the PfHog1 in the infected leaf tissues, which was further confirmed with quantification of the fungal biomass using absolute- quantitative PCR. Collectively, these findings demonstrate that PfHog1 plays a critical role in osmotic stress regulation and virulence of P. fijiensis on its host banana. Thus, PfHog1 could be an interesting target for the control of black Sigatoka disease in banana.
  • Thumbnail Image
    Item
    First report of banana bunchy top disease caused by Banana bunchy top virus in Uganda
    (Wiley, 2021-11-16) Ocimati, Walter; Tazuba, A.F.; Tushemereirwe, Wilberforce Kateera; Tugume, Joab; Omondi, Bonaventure Aman; Acema, Dan; Were, E.; Onyilo, Francis; Ssekamate, A.M.; Namanya, P.; Kubiriba, J.; Erima, R.; Okurut, A.W.; Kutunga, D.; Blomme, G.
    In August 2020, banana plants with characteristic symptoms of banana bunchy top disease (BBTD) caused by the Banana bunchy top virus (BBTV) were observed on two different banana (Musa sp.) mats in backyard gardens in Arua City (GPS coordinates: 2o59’36’’N 30o54’40’’E), West Nile region of Uganda. The plants were severely stunted with short, narrow leaves, chlorotic leaf margins and dark green streaks on petioles and midribs. The affected plants had a rosette-like or bunchy and choked appearance (Figures 1–2). A PCR using specific primers that amplify a 240 bp conserved domain of the BBTV DNA-mRep segment (Mansoor et al., 2005) confirmed the presence of BBTV in leaf, pseudostem and corm samples of the two symptomatic plants. The PCR product from one of the samples was purified and reverse sequenced (GenBank Accession No. OK066320). This sequence showed 98–99% nucleotide sequence identity with multiple BBTV isolates from India (e.g., KX219591, GU085264), Democratic Republic of Congo (DR Congo; e.g. KU687085, KU687070, KU687068), Benin (e.g. JQ437548), Burundi (e.g. JN204198), Australia (e.g. KM607586), USA (Hawaii; e.g., KM607599) and other African and South Pacific countries. To our knowledge, this constitutes the first report of BBTD in Uganda.
  • Thumbnail Image
    Item
    Pseudocercospora fijiensis cell fusion (Fus3) gene, complete cds
    (National Center for Biotechnology Information (NCBI), 2019-08-07) Onyilo, Francis
  • Thumbnail Image
    Item
    Pseudocercospora fijiensis high osmolarity glycerol (Hog1) gene, complete cds
    (National Center for Biotechnology Information (NCBI), 2019-08-07) Onyilo, Francis
  • Thumbnail Image
    Item
    Pseudocercospora fijiensis suppressor of the lytic phenotype (Slt2) gene, complete cds
    (National Center for Biotechnology Information (NCBI), 2019-08-07) Onyilo, Francis; Stergiopoulosq, I; Chen, L.-H.; Falk, B.; Odong, T. L.; Tripathi, J. N.; Tusiime, G.; Tripathi, L
  • Thumbnail Image
    Item
    Silencing of the Mitogen-Activated Protein Kinases (MAPK) Fus3 and Slt2 in Pseudocercospora fijiensis Reduces Growth and Virulence on Host Plants
    (Frontiers in Plant Science, 2018) Onyilo, Francis; Tusiime, Geoffrey; Tripathi, N. Jaindra; Chen, Li-Hung; Falk, Bryce; Stergiopoulos, Ioannis; Tushemereirwe, Wilberforce; Kubiriba, Jerome; Tripathi, Leena
    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 regulate infection processes and pathogenicity in P. fijiensis will provide important knowledge for the development of disease-resistant cultivars. In many fungal plant pathogens, the Fus3 and Slt2 are reported to be essential for pathogenicity. Fus3 regulates filamentous-invasion pathways including the formation of infection structures, sporulation, virulence, and invasive and filamentous growth, whereas Slt2 is involved in the cell-wall integrity pathway, virulence, invasive growth, and colonization in host tissues. Here, we used RNAi-mediated gene silencing to investigate the role of the Slt2 and Fus3 homologs in P. fijiensis in pathogen invasiveness, growth and pathogenicity. The PfSlt2 and PfFus3 silenced P. fijiensis transformants showed significantly lower gene expression and reduced virulence, invasive growth, and lower biomass in infected leaf tissues of East African Highland Banana (EAHB). This study suggests that Slt2 and Fus3 MAPK signaling pathways play important roles in plant infection and pathogenic growth of fungal pathogens. The silencing of these vital fungal genes through host-induced gene silencing (HIG) could be an alternative strategy for developing transgenic banana and plantain resistant to BSD.