Browsing by Author "Mushongi, Arnold"

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Characterization of Provitamin A Status and Distribution in Commercial Grown Maize Varieties in Tanzania
(East African Journal of Science, Technology and Innovation, 2022-02-16) Msungu, Selly; Venkataramana, Pavithravani; Mushongi, Arnold
Provitamin A carotenoids are important as precursors for vitamin A, essential for stronger immune system and eyesight. Consumption of a plant-based diet rich in provitamin A such as provitamin A maize is an easy and affordable source of vitamin A. The majority of the commercially grown maize varieties in Tanzania are white whose provitamin A status is uncertain and undocumented. The existing current information suggests that white maize varieties have low provitamin A, an active form of vitamin A, thus putting maize consumers at risk of vitamin A deficiency (VAD). Characterization of provitamin A status in commercial maize varieties grown and consumed in Tanzania is important to provide baseline information required for vitamin A rich-maize improvement programs. Therefore, this study was conducted to map the status of provitamin A in commercial maize varieties to accrue the information needed to improve maize nutrition quality toward controlling VAD in the country. The study involved 14 maize varieties including commercial yellow and white pigmented maize from 3 regions of Tanzania. From maize samples, carotenoid extraction was conducted based on published protocol. The concentration of beta carotene (BC), beta-cryptoxanthin (BCX), alpha-carotene (AC) were determined by an ultraviolet spectrophotometer and provitamin A computed for the individual carotenoids components. The study found that the concentration of provitamin A and associated carotenoids significantly differed (p<0.001) among varieties studied. The mean concentration (in μg/g) for provitamin A and its components in range as provitamin A (2.64-6.50), BC (1.91-4.66), BCX (0.649-1.21), and AC (0.819-1.46). The concentrations of provitamin A in the studied maize varieties were below the recommended levels (15 μg/g). The low concentrations of provitamin A among commercial maize varieties signify the need for introgressions of provitamin A in the adapted maize genotypes for ensured intake of vitamin A.
Integrating storage structures and store time in maize grains postharvest losses evaluation in Northern Zone of Tanzania
(INNSPUB, 2019-06-16) Swai, Jennifer; Mbega, Ernest; Mushongi, Arnold; Mwaijande, Violeth; Ndakidemi, Patrick
Maize is the most important cereal crop in Tanzania, thus its postharvest losses are a big threat to food security. This study integrated maize store-time with five storage methods namely Perdue Improved Cowpeas Storage bags (PICS), Metal Drums, Kihenge, Polyethylene bags with insecticides and Polyethylene bags without insecticide. Trials were established following a randomized complete block design with five treatments at Kilimanjaro, Arusha and Manyara, and treatments were monitored for weevil’s infestation for six months consecutive. The results showed PICS bag was the most efficient storage method in minimizing insect damaged kernels as it only contributed to 1% of the insect damaged kernels, while other methods such as Metal drum, Kihenge Polyethylene bag with insecticide and Polyethylene bag without insecticide resulted in 4%, 23 %, 29%, and 43% insect damaged kernels respectively after six month store‒time. The correlation matrix showed similar results with coefficients of correlation‒0.378, ‒0.272, 0.045, 0.037 and 0.516 respectively. With regards to store- time PICS bag and Metal drum had the lowest number of insect damage throughout six-month store-time. Polyethylene bag with insecticide was able to keep the kernel insect free only for three months while Polyethylene bag without insecticide kept grains free of weevil infestation only for one. There was no suggesting time to store grains using Kihenge due to its fewer numbers of observations
Molecular assessment of genetic diversity of Tanzanian and aflatoxin-resistant maize (Zea mays. L) accessions
(Springer International Publishing, 2024-05-28) Bundala, Gregory; Mng’ong’o, Marco; Mushongi, Arnold; Venkataramana, Pavithravani
Genetic distance information for various maize accessions is important for germplasm improvement and breeding program. However, this information is limited in most of the developing countries such as Tanzania. The present study was conducted to analyze the genetic diversity between Tanzanian maize accessions and the International Maize and Wheat Improvement Center (CIMMYT) lines as a strategy to create heterotic groups for maize breeding. Thirty Tanzanian maize accessions (14 inbred lines, 8 open-pollinated varieties, and 8 landraces) and 10 tester lines from CIMMYT were studied to estimate the molecular genetic variability using Euclidean distance determined by simple sequence repeat (SSR) markers. Fifteen SSR markers, resulting in general maize alleles, were used to determine genetic diversity, where 13 markers were amplified with an average PIC of 0.73. Where a moderate genetic distance between Tanzanian maize accessions and resistant lines, ranging from 0.13 to 0.57, was determined. The 40 maize genotypes (testers and accessions) were studied by using SSR markers classified into three major groups and further divided into 5 subgroups, which were later used to create the heterotic groups. The heterotic groups drawn and determined in phylogenetic tree showed distinct variations among studied genotypes. The study concludes that there is significant (P < 0.001) genetic diversity among the maize genotypes, which are essential breeding materials for producing superior maize hybrids with high combining ability and high heritability of traits of interest, such as high yielding and resistance to aflatoxin contamination. Thus, Tanzanian maize breeders can utilize the available maize genotypes to develop hybrids with high yield and resistance to aflatoxin contamination.
Post-harvest losses in maize store-time and marketing model perspectives in Sub-Saharan Africa
(Academic Journals, 2019-01-31) Swai, Jennifer; Mbega, Ernest; Mushongi, Arnold; Ndakidemi, Patrick
Postâ€’harvest losses of maize are almost half of the produced grains in Subâ€’Saharan Africa. Efforts to reverse this trend are recommended. Thus, there is a prerequisite to create a postâ€’harvest loss resilient strategy to guide small scale maize growing farmers in Africa. In this review, critical elements underlying postâ€’harvest losses in Africa such as infestation by insectâ€’pests, microbes, rodents, poor transportation infrastructure, poor storage facilities, injudicious storeâ€’time and unjustified marketing models have been discussed. Furthermore, we have proposed options for mitigating the postâ€’harvest damage by highlighting possible pathways for farmers’ friendly resilient strategies and areas needing research to eventually minimize postâ€’harvest losses of maize in Sub Saharan Africa
Prevalence of aflatoxigenic fungi and contamination in soils and maize grains from aflatoxin-hot spot areas in Tanzania
(Elsevier, 2024-11-01) Kwigizile, Owekisha; Mbega, Ernest; Mushongi, Arnold; Philipo, Mashamba
Maize is a major food security crop contributing over 50 % of total food requirement in Tanzania. However, number of factors limit its production and quality. Aflatoxins contamination mostly produced by two Aspergillus species, A. flavus and A. parasticus compromise food safety, public health and economic concern globally. Despite its harmful effects little is documented on the aflatoxin- producing fungi on prevalence’s and contamination levels in soils and maize. The present study investigated Aflatoxigenic occurrence and aflatoxins contamination extents in seven districts. A total of 126 soil and 126 maize samples were collected and analyzed for presence, dominance, and levels of aflatoxin contaminations. Serial dilution and direct plating techniques were used for fungal isolation from soil and maize respectively and macro morphology characterization were used for identification. Aflatoxin levels were detected by High-Performance Liquid Chromatography. A. flavus (38.1 %), A. parasiticus (22.2 %) and A. niger (16.7 %) were found to be the most dominant linked to aflatoxins B1 contamination. Total Aflatoxins were detected in Bahi (72.2 %, with mean of 87.9 μg/kg), Chemba (61.2 %, 74.2 μg/kg), and Babati (56.3 %, 65.8 μg/kg) indicating these were more prone to aflatoxins and higher aflatoxigenic prevalence. Aflatoxin B1 was detected most in Bahi (22.4 %, 402.4 μg/kg), Chemba (13.4 %, 241 μg/kg), and Babati (11.1 %, 199.2 μg/kg). Fungal counts ranged 3.4 ×105 to 6.9 ×107 CFU/g for contaminated samples. Aflatoxigenic species varied significantly (P<0.001) between cropping systems and the locations. Aflatoxigenic occurrence and levels were shown to be influenced by the cropping systems, as evidenced by the soils exhibiting a higher frequency than maize grains. Compared to mixed cropping, the mono-cropping system exhibited the greatest levels of aflatoxigenic population and aflatoxin contamination, indicating that farming practices affect contaminations and the need for improved cropping system practices.
A review on the trends of maize biofortification in alleviating hidden hunger in sub-Sahara Africa
(Elsevier Ltd., 2022-06-01) Msungu, Selly; Mushongi, Arnold; Venkataramana, Pavithravani; Mbega, Ernest
Micronutrient deficiency is a major problem affecting many people in developing countries who solely depend on maize as their single source of calories. Vitamin A deficiency is one of the health problems associated with micronutrient deficiency. It is caused by insufficient intake of food rich in vitamin A among vulnerable groups leading to impaired growth, reduced life span, and economic losses among resource-poor families. Strategies such as vitamin A supplementation, food fortification, and diet diversification have been adapted to combat vitamin A deficiency (VAD). However, these approaches have benefited urban dwellers leaving rural residents with deficiency sufferings, as they lack access to these alternatives. Biofortification of maize by breeding with higher provitamin A content holds immense promise as a cost-effective and sustainable approach in alleviating VAD in sub-Saharan African maize consumers. Biofortified maize has a greater potential to alleviate vitamin A deficiency in these countries. Despite the existence of biofortification programs in Africa, there is little documentation on what has been conducted, challenges, and future of maize biofortification programs in Africa; this limits any strategic planning required to produce maize varieties rich in micronutrients, including vitamin A. Therefore, the present study is a detailed systematic review to highlight the past, present, and future success of provitamin A maize biofortification and its adoption challenges in sub-Sahara Africa as a strategy for combating vitamin A deficiency.
Role of Potyviruses in Synergistic Interaction Leading to Maize Lethal Necrotic Disease on Maize
(International Journal of Current Microbiology and Applied Sciences, 2016-06-10) Mbega, Ernest; Ndakidemi, Patrick; Mamiro, Delphina; Mushongi, Arnold; Kitenge, K.; Ndomba, O.
Synergistic interactions among pathogenic viruses are common in plants. Though not all, but a number of reported cases involving such interactions have a potyvirus partner during co-infection. The presence of the potyvirus group seems to favor its own multiplication on host and multiplication of a co-infecting partner. In this review, some characteristics favoring higher pathogenesis have been discussed using maize lethal necrosis (MLN)- causing viruses namely Maize chlorotic mottle virus (MCMV) and its synergistic potyvirus, Sugarcane mosaic virus (SCMV). A comprehensive discussion on the role of potyvirus in the synergism has been presented to show that in MLN and similar synergisms - the machinery for induction, transmission and colonization of the host is catalysed by the potyvirus and not the co-infecting viral partner which otherwise seems to be the most virulent in the synergism-based diseases such as MLN disease in maize. Furthermore, the effect of MLN to food security and areas for future research for Africa has been discussed in this review.
Status of carotenoids in elite and landrace maize genotypes: Implications for provitamin A biofortification in Tanzania
(Elsevier Ltd., 2022-06-01) Msungu, Selly; Mushongi, Arnold; Venkataramana, Pavithravani; Mbega, Ernest
Maize is among the crops containing carotenoids that are easily converted to vitamin A and have an enormous influence on consumers' health. Principally maize has high calories and proteins but has less number of other micronutrients such as vitamin A. Societies that use maize as their main and sole staple food are likely to be affected by vitamin A deficiency. Thus, development and production of maize varieties rich in micronutrients and vitamin A are important for improved health. This study characterized 5 carotenoid components in maize genotypes grown in Tanzania as a strategy for improving vitamin A content in maize. The study involved maize landraces, commercial or elite varieties, and inbred lines in determining their potential for provitamin A breeding programs for nutrition improvement. The study found that mean concentration of important carotenoid components, i.e., alpha carotene (AC), beta-carotene (BC), beta-cryptoxanthin (BCX), lutein (LU), zeaxanthin (ZX), provitamin A (ProVA), non-provitamin A (Non-ProVA), and total carotenoids (TC) varied significantly (P < 0.001) among maize genotypes. The 3 maize groups studied (landraces, commercial varieties, and breeding materials (BMs) varied significantly. For maize landraces, the concentration (µg/g) of studied carotenoids were AC (0.13–2.67), BC (0.60–3.72), BCX (0.36–1.01), ProVA (0.89–5.29), Retinol (0.25–0.87), LU (2.37–16.97). ZX (0.16–4.41), Non-ProVA (2.4–19.01), and TC (3.68–25.27); in commercial or elite maize varieties were (in µg/g): AC (0.31–3.84), BC (0.56–6.5), BCX (0.46–2.58), ProVA (0.92–11.80), Retinol (0.15–1.82), LU (3.28–22.39). ZX (0.05–11.31), Non-ProVA (2.56–28.81), and TC (4.23–37.84); and for maize BMs AC (0.53–6.64), BC (1.92–13.87), BCX (0.65–6.51), ProVA (2.69–18.62), Retinol (0.5–3.1), LU (4.86–34.99), ZX (0.06–18.58), Non-ProVA (4.8–53.57), and TC (9.86–76.94). Furthermore, the study found that the concentration of studied carotenoids was higher in pigmented (yellow or red) maize genotypes than in white maize genotypes. The current study found an appreciable amount of ProVA in studied materials, including maize landraces, commercial yellow varieties, and CIMMYT lines. The concentration of ProVA and retinol determined in studied maize genotypes were below 15 µg/g a daily vitamin A requirement, thus based on the current ProVA and retinol status it is difficult to meet Vitamin A requirement. Therefore, these maize genotypes with promising levels of carotenoid components are potential breeding materials that can be used in maize provitamin A biofortification program for improved food nutrition and livelihoods in Tanzania.