Browsing by Author "Alicai, Titus"

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    Comparative analysis of oil palm extraction rates and nutritional profiles of indigenous and introduced hybrid genotypes cultivated in selected districts of Uganda
    (Taylor & Francis, 2026-04-04) Caku, Jimmy; Ddamulira, Gabriel; Nuwamanya, Ephraim; Ddumba, Gerald; Mahipal, Kesawat Singh; Asiimwe, Alex; Amugoli, Otuba Moses; Alicai, Titus; Masika, Fred Bwayo
    Oil palm (Elaeis guineensis Jacq. L.) is the leading global source of plant-based oil. However, Uganda relies on imported hybrid varieties because it lacks a domestic breeding program. To inform potential breeding efforts, this study evaluated oil extraction rates and nutritional profiles of indigenous and introduced hybrid oil palm genotypes cultivated in Bundibugyo, Kanungu, and Kalangala districts. Seventy-five ripe fruit bunches were collected, and palm oil was extracted using a screw press. Measurements of oil extraction rate and stearin mass recovery were performed. Nutritional analysis of olein samples included carbohydrate quantification via the Anthrone method; fatty acid quantification (linolenic, linoleic, oleic, palmitic, and stearic acids) using High-Performance Liquid Chromatography (HPLC) with UV detection; and beta-carotene concentration determined using spectrophotometry. Statistical differences between groups were assessed using the non-parametric Kruskal-Wallis H test, as data for most variables did not meet the assumptions for parametric tests. Indigenous genotypes showed slightly higher mean oil extraction rates (23.3%) and stearin recovery (22.6%) than hybrids (22.8 and 17.9%, respectively). These results highlight the potential of indigenous genotypes as promising candidates for breeding programs aimed at enhancing oil yield and nutritional quality under Uganda’s agro-ecological conditions. The study provides foundational data to support the development of a sustainable, locally adapted oil palm breeding initiative.
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    Efficient conditions for in vitro establishment and regeneration of disease-free Ugandan farmer-preferred cassava genotypes
    (African Journal of Biotechnology, 2021-08-18) Apio, Hellen B; Alicai, Titus; Ogwok, Emmanuel
    Cassava (Manihot esculenta Crantz) is majorly devastated by two viral diseases, cassava brown streak disease (CBSD) and cassava mosaic disease (CMD), resulting in 100% yield loss. Being a clonal plant, nodal cuttings (NC) and shoot apical meristems (SAMs) are the best explants for production of disease free planting materials. In this study, NCs and SAMs were used to determine reliable indicators for successful in vitro establishment of cassava. Eight cassava genotypes were used for the study. Leaf samples were collected from 30 stakes of each of the eight genotypes planted in the screen house. The leaf samples were pooled and screened for presence and/or absence of CBSD and CMD by PCR using virus specific primers. Nodal cuttings were excised from screen house grown plants, surface sterilized to rid-off contaminants and established on Murashige and Skoog (MS) Medium. Using the sprouted stakes, 5-mm sized SAMs were excised, surface sterilized and reduced to 0.5-1 and 2-3 mm sizes. The SAMs were established on MS medium with varying concentrations of plant growth regulators (0.5, 1, 2) ml/L Benzylaminopurine (BAP) and (2, 4) ml/L Naphthalene acetic acid (NAA), Kinetin (K) and BAP respectively. PCR results revealed the pooled leaf samples were free of both CBSD and CMD for all genotypes. Establishment and regeneration of NCs was possible with MS medium for all genotypes. For the SAMs, the concentrations of (2, 4) ml/LBAP followed by 2 ml/LNAA facilitated their establishment and regeneration in comparison to KIN.SAMs of 2-3 mm sizes regenerated better than 0.5 - 1 mm size. Both NCs and SAMs of the different genotypes produced leaves, nodes, roots and there was an increase in plant length. These parameters are critical indicators for in vitro establishment and regeneration of cassava.
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    High-throughput sequencing analysis reveals Moroccan Watermelon Mosaic Virus and Tobacco Streak Virus isolates infecting pumpkins in Uganda
    (CABI Agriculture and Bioscience, 2025-08-01) Masika, Fred Bwayo; Tugume, Arthur K.; Kesawat, Mahipal S.; Shimelis, Hussein; Ddamulira, Gabriel; Athman, Shahasi Y.; Ipulet, Perpetua; Alicai, Titus
    Pumpkin (Cucurbita pepo L.) is a globally cultivated, economically significant cucurbit species, yet viral diseases pose a major threat to its yield and quality, especially in key production areas such as Uganda. To investigate and document viruses affecting pumpkins in Uganda, we assessed the sub-regional severity of virus-like diseases and identified pumpkin-infecting viruses using RNA sequencing. A total of 75 pumpkin leaf samples displaying typical viral symptoms were collected from 66 fields across Uganda. These samples were then pooled into five bulk groups, each consisting of 15 different plant leaves. Our analysis identified two viruses and detected six viruses, which were, however, not confirmed by another method. The two identified viruses were Moroccan Watermelon Mosaic Virus (MWMV) and Tobacco Streak Virus (TSV). This is the first report of MWMV and TSV infecting pumpkins in Uganda. The virus-like disease symptoms exhibited variations in sub-regional severity and incidence. These findings highlight the current viral diversity in pumpkins in Uganda, providing critical information for developing integrated disease management strategies to enhance crop yield and productivity.
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    Seasonal dynamics of Elaeidobius Kamerunicus in allopatric populations: comparative analysis from indigenous mainland and introduced oil palm ecosystems in Uganda’s lake Victoria islands
    (Taylor & Francis, 2026-02-04) Masika, Fred Bwayo; Otuba, Amugoli Moses; Kesawat, Mahipal Singh; Asiimwe, Alex; Baguma, Bidget; Alicai, Titus; Manohar, Swati; Ddamulira, Gabriel
    Oil palm (Elaeis guineensis L.), native to Africa but widely cultivated in Southeast Asia, is increasingly grown in Uganda, and pollination efficiency is critical for fruit set and oil yield. The study assessed the population and sexual diversity of the primary pollinator, Elaeidobius kamerunicus FAUST, in introduced hybrid plantations in Kalangala and natural stands in Bundibugyo. Pollinator weevils were sampled across both wet and dry seasons in 2022 and 2023, and data were analyzed using ANOVA and correlation tests in Minitab 17. Results revealed significant variation between sites, with higher populations in Kalangala (7,503 ± 8.682) compared to Bundibugyo (5,164 ± 5.829). Furthermore, females (6,636 ± 4.646) outnumbered males (6,032 ± 5.028), with a slightly higher concentration of females in the middle section of male inflorescences. Seasonal differences were evident, as the wet season supported slightly higher weevil populations relative to the dry season. Correlation analysis indicated a weak negative relationship between weevil abundance and weather variables, suggesting that cooler conditions suppress population growth. Overall, Uganda provides favorable conditions for pollinator weevil multiplication, particularly under moist climatic regimes, while extensive cold conditions limit population expansion. These findings highlight the importance of pollinator dynamics in sustaining oil palm productivity in diverse agroecological regions.
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    Unlocking Ugandan pumpkin landrace diversity: integrated morphological and nutritional profiling for food security and breeding innovation
    (Taylor & Francis, 2026-04-13) Masika, Fred Bwayo; Anywar, Godwin; Kesawate, Mahipal Singh; Ddamulira, Gabriel; Kawuma, Caro; Andama, Morgan; Ajoma, Charity; Ramathan, Iddi; Amugoli, Otuba Moses; Caku, Jimmy; Alicai, Titus; Nuwamanya, Ephraim; Tugume, Arthur K.
    Pumpkins (Cucurbita spp.) are vital for food and nutritional security in Uganda, yet their full potential remains underexploited due to the limited characterization of traits. To address this, 91 landraces, 21 Cucurbita pepo and 70 Cucurbita moschata were collected from 19 districts across major agroecological zones, evaluated for morpholological and nutritional diversity. Results revealed wide phenotypic variation with fruit weights ranging from 0.5 to 10.0 kg and shapes varying from discoid (L/D 0.44) to highly elongated (L/D 4.00). Fruit size and shape were independent axes of variation. Regionally, Buganda and Bunyoro landraces produced larger fruits, averaging 3.84 kg and 4.07 kg, while West Nile landraces formed a distinct nutrient-rich cluster, with high dry matter (22.8%), lipids (3.75% fresh weight (FW), fiber (3.34% FW), and carbohydrates (4.07% FW). District-specific differences were also observed, with Mpigi landraces rich in phenolics content (0.062 ± 0.0023 g GAE/100 g), and Mukono landraces rich in proteins (0.000887 g/100 g). Importantly, external morphology poorly predicted internal nutritional quality, highlighting the need for direct biochemical profiling in breeding programs. This study provides Uganda’s first nationally structured dataset on pumpkin diversity, offering a scientific foundation for targeted germplasm conservation, nutrient-enriched cultivar development and policy interventions to strengthen food systems across diverse agroecological zones in Uganda.