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The genetic diversity of leaf vegetable jute mallow (Corchorus spp.): A review
(2017-09-15) Ngomuo, Munguatosha; Stoilova, Tsvetelina; Feyissa, Tileye; Kassim, Neema; Ndakidemi, Patrick
Corchorus spp. is among traditional vegetable which is very nutritious and has been in use in many households in Africa. It contains high level of carotenoids (150µg/100g), vitamin C, Iron (190µg/g), 1.3% Calcium and 25.0% protein. The leaves are used in treatment of diseases and have wide antibacterial properties. It is semidomesticated and sometimes grows as a volunteer crop. Its status in some parts of Tanzania as a wild plant renders it unappealing for consideration in crop development programs.There is limited scientific information on its diversity for use as a vegetable in crop improvement and is a potential area for research. Variations exist among different accessions based on leaf shapes and color. Diversity studies by using molecular markers, proteins and isozymes are reported by several authors. There is low variation within species and high among species. Most of released varieties have a narrow genetic base. Conservation of this species in Africa is scarcely reported.
Patterns of tsetse abundance and trypanosome infection rates among habitats of surveyed villages in Maasai steppe of northern Tanzania
(BioMed Central Ltd., 2017-09-04) Ngonyoka, Anibariki; Gwakisa, Paul; Estes, Anna; Salekwa, Linda; Nnko, Happiness; Hudson, Peter; Cattadori, Isabella
Background: Changes of land cover modify the characteristics of habitat, host-vector interaction and consequently infection rates of disease causing agents. In this paper, we report variations in tsetse distribution patterns, abundance and infection rates in relation to habitat types and age in the Maasai Steppe of northern Tanzania. In Africa, Tsetse-transmitted trypanosomiasis negatively impacted human life where about 40 million people are at risk of contracting the disease with dramatic socio-economical consequences, for instance, loss of livestock, animal productivity, and manpower. Methods: We trapped tsetse flies in dry and wet seasons between October 2014 and May 2015 in selected habitats across four villages: Emboreet, Loiborsireet, Kimotorok and Oltukai adjacent to protected areas. Data collected include number and species of tsetse flies caught in baited traps, PCR identification of trypanosome species and extraction of monitored Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectrometer (MODIS). Results: Our findings demonstrate the variation of tsetse fly species abundance and infection rates among habitats in surveyed villages in relation to NDVI and host abundance. Results have shown higher tsetse fly abundance in Acacia-swampy ecotone and riverine habitats for Emboreet and other villages, respectively. Tsetse abundance was inconsistent among habitats in different villages. Emboreet was highly infested with Glossina swynnertoni (68%) in ecotone and swampy habitats followed by G. morsitans (28%) and G. pallidipes (4%) in riverine habitat. In the remaining villages, the dominant tsetse fly species by 95% was G. pallidipes in all habitats. Trypanosoma vivax was the most prevalent species in all infected flies (95%) with few observations of co-infections (with T. congolense or T. brucei). Conclusions: The findings of this study provide a framework to mapping hotspots of tsetse infestation and trypanosomiasis infection and enhance the communities to plan for effective control of trypanosomiasis.
Pastoralists’ Vulnerability to Trypanosomiasis in Maasai Steppe
(Springer New York LLC, 2017-09-04) Nnko, Happiness; Gwakisa, Paul; Ngonyoka, Anibariki; Saigilu, Meshack; Ole-Neselle, Moses; Kisoka, William; Sindato, Calvin; Estes, Anna
Trypanosomiasis is a neglected tropical disease of both livestock and humans. Although pastoral communities of the Maasai Steppe have been able to adapt to trypanosomiasis in the past, their traditional strategies are now constrained by changes in climate and land regimes that affect their ability to move with their herds and continually shape the communities’ vulnerability to trypanosomiasis. Despite these constraints, information on communities’ vulnerability and adaptive capacity to trypanosomiasis is limited. A cross-sectional study was therefore conducted in Simanjiro and Monduli districts of the Maasai Steppe to establish pastoralists’ vulnerability to animal trypanosomiasis and factors that determined their adaptation strategies. A weighted overlay approach in ArcGIS 10.4 was used to analyze vulnerability levels while binomial and multinomial logistic regressions in R 3.3.2 were used to analyze the determinants of adaptation. Simanjiro district was the most vulnerable to trypanosomiasis. The majority (87.5%, n = 136) of the respondents were aware of trypanosomiasis in animals, but only 7.4% (n = 136) knew about the human form of the disease. Reported impacts of animal trypanosomiasis were low milk production (95.6%, n = 136), death of livestock (96.8%, n = 136) and emaciation of animals (99.9%, n = 136). Crop farming was the most frequently reported animal trypanosomiasis adaptation strategy (66%, n = 136). At a 95% confidence interval, accessibility to livestock extension services (β = 7.61, SE = 3.28, df = 135, P = 0.02), years of livestock keeping experience (β = 6.17, SE = 1.95, df = 135, P = 0.001), number of cattle owned (β = 5.85, SE = 2.70, df = 135, P = 0.03) and membership in associations (β = − 4.11, SE = 1.79, df = 135, P = 0.02) had a significant impact on the probability of adapting to animal trypanosomiasis.
Clipping and irrigation enhance grass biomass and nutrients: Implications for rangeland management
(Elsevier B.V., 2017-05-01) Tuffa, Samuel; Hoag, Dana; Treydte, Anna
Increasing frequency of drought and high herbivore pressure significantly affect individual grass functions in semiarid regions. Reseeding of degraded rangelands by native grass species has been recommended as a tool for restoration semiarid rangelands. However, how grass species used for reseeding respond to stressors has not been fully explored. We examined biomass allocation and nutrient contents of Cenchrus ciliaris and Chloris gayana in the semiarid Borana rangelands, Ethiopia. We tested clipped mature tufts of the same species for biomass allocation and nutritive values. Further, shifts in rainfall and herbivory were simulated by three irrigation and four clipping treatments, respectively, for newly established grasses in pot and field plot experiments. Aboveground biomass (AGB) significantly declined by up to 75% under increased clipping in mature tufts. In contrast, clipping significantly stimulated up to 152% higher AGB of newly established grasses. Lower irrigation reduced the AGB by 24 and 42% in C. ciliaris and in C. gayana, respectively. Clipping, further, significantly enhanced grass nutrients in grass tufts by up to 82 and 105% in C. ciliaris and C. gayana, respectively. Hence, management should focus on balancing this trade-off in mature grasses for nutritious rangeland production by clipping and storing for later supplemental feeding when grass nutrients drop. Further, young pastures should be moderately clipped/grazed for better establishment and biomass allocation. Additionally, our experiments established the first interactive effect of clipping and irrigation frequencies on the biomass allocation of native grasses in the semiarid Borana rangelands, Ethiopia. Knowledge of these interacting factors is deemed essential for policy makers to enhance productivity of degraded rangelands such as the Borana rangelands.
Medical pluralism and livestock health: Ethnomedical and biomedical veterinary knowledge among East African agropastoralists
(BioMed Central Ltd, 2017-01-17) Caudell, Mark; Quinlan, Marsha; Quinlan, Robert; Call, Douglas
Background Human and animal health are deeply intertwined in livestock dependent areas. Livestock health contributes to food security and can influence human health through the transmission of zoonotic diseases. In low-income countries diagnosis and treatment of livestock diseases is often carried out by household members who draw upon both ethnoveterinary medicine (EVM) and contemporary veterinary biomedicine (VB). Expertise in these knowledge bases, along with their coexistence, informs treatment and thus ultimately impacts animal and human health. The aim of the current study was to determine how socio-cultural and ecological differences within and between two livestock-keeping populations, the Maasai of northern Tanzania and Koore of southwest Ethiopia, impact expertise in EVM and VB and coexistence of the two knowledge bases. Methods An ethnoveterinary research project was conducted to examine dimensions of EVM and VB knowledge among the Maasai (N = 142 households) and the Koore (N = 100). Cultural consensus methods were used to quantify expertise and the level of agreement on EVM and VB knowledge. Ordinary least squares regression was used to model patterns of expertise and consensus across groups and to examine associations between knowledge and demographic/sociocultural attributes. Results Maasai and Koore informants displayed high consensus on EVM but only the Koore displayed consensus on VB knowledge. EVM expertise in the Koore varied across gender, herd size, and level of VB expertise. EVM expertise was highest in the Maasai but was only associated with age. The only factor associated with VB expertise was EVM expertise in the Koore. Conclusions Variation in consensus and the correlates of expertise across the Maassi and the Koore are likely related to differences in the cultural transmission of EVM and VB knowledge. Transmission dynamics are established by the integration of livestock within the socioecological systems of the Maasai and Koore and culture historical experiences with livestock disease. Consideration of the nature and coexistence of EVM and VB provides insight into the capacity of groups to cope with disease outbreaks, pharmaceutical use patterns, and the development of community health interventions.
Socio-economic correlates and management implications of livestock depredation by large carnivores in the Tarangire ecosystem, northern Tanzania
(Taylor and Francis Online, 2017-07-29) Mkonyi, Felix; Estes, Anna; Msuha, Maurus; Lichtenfeld, Laly; Durant, Sarah
Livestock depredation by large carnivores is the key source of human–carnivore conflict worldwide and entails financial losses to livestock keepers. We examined the extent and patterns of livestock depredation, the financial impacts of livestock losses and determinants of livestock depredation by large carnivores in the Tarangire ecosystem of northern Tanzania. Of 300 households surveyed, 74.7% reported losses of 1906 livestock to wild predators over 1.5 years, which represents an annual loss rate of 1.4% of their total herd. Spotted hyena (Crocuta crocuta) accounted for 70% of the total livestock loss, followed by leopard (Panthera pardus) (12%), African wild dog (Lycaon pictus) (8%), lion (Panthera leo) (7%) and cheetah (Acinonyx jubatus) (3%). This loss equated to a total financial loss of US$141,847 amounting to approximately US$633/household/year. Depredation frequency by all carnivore species increased significantly with increasing number of livestock owned, respondent’s residency time, distance from the park boundary and declined significantly with increasing education, number of herders and improved fortified boma for cattle. Livestock depredation peaked during the wet season linked to seasonal migration of wild prey. Our study suggests that improving formal and conservation awareness education, boma fortification as well as improving herding practices could help mitigate the human–carnivore conflict.
Genetic diversity of maize accessions for maize lethal necrosis disease resistance
(Agricultural Research Communication Centre, 2017-02-07) Kabululu, Mujuni; Ndunguru, Joseph; Ndakidemi, Patrick; Feyissa, Tileye
Maize is among the most preferred crop in Tanzania and other parts of the world. However, its production has been facing a number of challenges. Maize Lethal Necrosis Disease (MLND) is a new challenge in Eastern Africa. The control of MLND is said to be complicated as it is caused by a combination of more than one virus viz. Maize Chlorotic Mottle Virus (MCMV) and Sugarcane Mosaic Virus (SCMV). Stakeholders agree that the priority is to identify MLND resistant maize varieties. Genetic diversity provides the source of traits required against maize production challenges such as MLND. The study of genetic diversity in maize accessions often involves characterizing morphological plant characteristics as well as molecular marker techniques to study variation at DNA level. This review explores different literatures that address the importance of genetic diversity and the possibility of generating information towards obtaining potential materials against maize challenges and MLND in particular.
Risk of dietary exposure to aflatoxins and fumonisins in infants less than 6 months of age in Rombo, Northern Tanzania
(Blackwell Publishing Ltd, 2016-07-01) Magoha, Happy; Kimanya, Martin; De Meulenaer, Bruno; Roberfroid, Dominique; Lachat, Carl; Kolsteren, Patrick
Infants less than 6 months of age receiving foods other than breast milk are at a high risk of exposure to mycotoxins. We surveyed food intake and estimated the risk of exposures to aflatoxin and fumonisin mycotoxins for infants less than 6 months of age in Northern Tanzania. A total of 143 infants were progressively recruited and three follow-up visits were made at 1, 3 and 5 months of age. A 24-h dietary recall technique was used to estimate flour intake of infants who had been introduced to maize foods. Aflatoxins and fumonisins in the flours were analysed using high-performance liquid chromatography technique. Exposure to aflatoxins or fumonisins was estimated using the deterministic approach. By the age of 3 months, 98 infants had started taking food; 67 of them, maize flours at levels ranging from 0.57 to 37.50 g per infant per day (average 8 g per infant per day). Fifty-eight per cent of 67 maize flour samples contained detectable aflatoxins (range 0.33-69.47 μg kg(-1) ; median 6 μg kg(-1) ) and 31% contained detectable fumonisins (range 48-1224 μg kg(-1) ; median 124 μg kg(-1) ). For infants who consumed contaminated flours, aflatoxin exposure ranged from 0.14 to 120 ng kg(-1) body weight (BW) per day (all above the health concern level of 0.017 ng kg(-1) BW per day as recommended by the European Food Safety Agency) and fumonisin exposure ranged from 0.005 to 0.88 μg kg(-1) BW per day. Insignificant association was observed between exposure to fumonisins or aflatoxins and stunting or underweight. Reducing aflatoxin and fumonisin contamination of maize and dietary diversification can prevent infants and the public, in general, from exposure to the toxins.
Incremental effect of natural tick challenge on the infection and treatment method-induced immunity against T. parva in cattle under agro-pastoral systems in Northern Tanzania
(Elsevier, 2015-07-01) Kazungu, Yvette; Mwega, Elisa; Neselle, Moses; Sallu, Raphael; Kimera, Sharadhuli; Gwakisa, Paul
This study was conducted to assess the incremental effect of natural tick challenge on the infection and treatment method-induced immunity against T. parva under agro-pastoral systems in Simanjiro district, Northern Tanzania. T. parva specific antibody percent positivity and prevalence of T. parva parasites were studied in relation to duration post vaccination and proximity to Tarangire National park. A total of 381 cattle were included in this study, of which 127 were unvaccinated and 254 had been vaccinated at different time points between 2008 and 2014. Antibody percent positivity (PP) determined by the PIM-based T. parva ELISA and the prevalence of T. parva parasites detected by a nested PCR based on the p104 gene were used to compare vaccinated and unvaccinated cattle. Results showed that seroprevalence was significantly higher in vaccinated than unvaccinated cattle (OR 10.89, p = 0.0341). Only 1.6% (6/381) of all cattle were seronegative and 5/6 of these were unvaccinated. Prevalence of T. parva parasites was significantly higher in vaccinated (50.39%) than unvaccinated (19.69%) cattle (OR 2.03, p = 0.0144). While there was a positive association between PP and duration post vaccination but the latter was inversely associated with T. parva parasite prevalence. This study also showed that cattle which were closer to the park had higher antibody PP and T. parva prevalence. It is concluded that duration post vaccination as well as proximity from the wildlife in Tarangire National park together may exert an incremental effect on the outcome of ECF vaccination by influencing stronger antibody immunity of cattle and ability to withhold high T. parva infection pressure under constant field tick challenge. Further, the high seroprevalence in vaccinated and unvaccinated cattle suggests a likely state of endemic stability to T. parva in the study area.
Review on the secondary metabolites, biological properties, and ethnomedicinal uses of the component species of the buheri wa afya formula used to treat COVID-19 in Tanzania
(Elsevier B.V., 2024-02) Makangara, John; Mshandete, Anthony; Mbega, Ernest; Nyika, John; Mbago, Frank; Ndilanha, Edward; Nyika, Raphael; Nyika, Joseph
Background It has proven difficult to treat viral infections like SARS-CoV, MERS-CoV, and SARS-CoV-2 that cause severe respiratory disorders with the currently available medications. Alternative strategies for combating viral infections are required to adequately treat infectious diseases like COVID-19. The most potent of them all may be plant-based products or herbal remedies. Following the advent of the COVID-19 epidemic, a number of alternative medicine practitioners in Tanzania developed herbal medicine formulations, claiming that they were effective in treating COVID-19 patients. One among the formulations is Buheri wa Afya, meaning "good health". The rationale for choosing Buheri wa Afya over the other formulations was justified by its efficacy in treating COVID-19 patients at different stages of the illness. Purpose This review aimed to collect information on the chemical composition, biological properties, and ethnomedicinal uses of the constituents of Buheri wa Afya formula, a plant-fungi complex formula made of Adansonia digitata L., Ficus sur Forssk, Securidaca longipedunculata Fresen, Syzygium cumini (L.) Skeels, and Zanthoxylum chalybeum Engl., and a fungus, Ganoderma tsugae Murrill, that was and is still used for the treatment of COVID-19 in Tanzania. Methods All information regarding ethnomedical applications, chemical compositions, and biological properties related to the constituents of the herbal formula was collected from PubMed, Research4Life, Google Scholar, Science Direct, Web of Science, Wiley Online Library, Springer, Research Gate link, and published books. Results The search, which mostly focused on COVID-19 and other viral infectious diseases produced a total of 183 publications, with publication dates ranging from 1984 to 2023. Most of the articles originated from African and Asian (specifically China and India) countries. A total of 16 articles spanning between 1984 through 1999 reporting on a variety of topics, such as isolation of compounds and biological testing were collected. During that time, Ganoderma species had the highest number of reported occurrences. In contrast to the 25 papers collected between 2000 and 2009, 78 articles covering the years 2010 through 2019 were collected. These 103 articles reported studies on ethnomedicinal uses, pharmacological properties, and chemical compositions of the plants and mushrooms under review. During the 2020–2023 period, a total 67 different articles were gathered, the major focus being the fight against COVID-19 and other viral infectious diseases. Twelve of them reported the ethnomedical applications of the investigated plant and mushroom species in the Buheri wa Afya formula in the management and treatment of COVID-19 and associated symptoms. The majority of articles reported the presence of a variety of biologically active compounds, including vitamins, flavonoids, phenols, coumarins, alkaloids, terpenoids, macronutrients, and micronutrients. According to the studies, the compounds have been reported to exhibit anti-inflammatory, immunomodulatory, antiviral, antioxidant, antimalarial and many other biological properties. The combination of the observed biological properties of the plant and mushroom species in the Buheri wa Afya formula may be responsible for its effectiveness in the treatment of COVID-19 in Tanzania. Conclusions The literature has highlighted the indispensable importance of using bBuheri wa Afya as an effective alternative therapy in the management of viral infectious diseases like COVID-19. Various studies reviewed in this study have revealed the potentials of the constituents of Buheri wa Afya in fighting against COVID-19 and other viral infections. Thus, Buheri wa Afya formula with the intrinsic antioxidant, anti-inflammatory, antiviral and immunomodulating properties of its constituents justifies the observed effectiveness of the formula in protection, alleviation of symptoms, and cure of COVID-19 in Tanzania.
Seroprevalence and carrier state of Theileria parva in cattle under two tick control regimes in small-holder farming systems of Tanzania
(Fundacion CIPAV, 2015-06-03) Kazungu, Y.; Mwega, E.; Kimera, S.; Gwakisa, P.
A cross-sectional study of T. parva antibody and parasite prevalence was conducted on smallholder farms in Tanzania to compare the impact of two tick control regimes. A total of 182 cattle were sampled, whereby 104 were under constant exposure to ticks with minimal or sporadic tick control and 78 animals were kept in a regular weekly or bi-weekly tick control. Across the two sites, 179 cattle were positive for T. parva antibodies determined by a PIM ELISA corresponding to an overall seroprevalence of 98.4%. Using a nested p104 PCR, prevalence of T. parva parasites was shown to be 37.1% across the two sites. Cattle under the sporadic tick control had significantly higher antibody levels compared to those managed under regular tick control (p=0.0014). Highest T. parva antibody percent positivity was 62.1 for cattle under regular tick control, but this parameter was 87.3 in cattle under sporadic tick control. On the contrary, T. parva PCR results revealed a significantly higher parasite prevalence in cattle under regular tick control (p<0.0001). The detection of low T. parva parasite prevalence in combination with high antibody responses points to a carrier state which may not support clinical disease but be advantageous for the establishment of endemic stability in the populations. We discuss the importance of these findings in the understanding of the epidemiology of ECF in endemic settings where tick control regimes vary and in the context of development of more effective control strategies for smallholder farming systems in endemic areas. © 2015 Fundacion CIPAV. All rights reserved.
The dynamics and environmental influence on interactions between cassava brown streak disease and the whitefly, Bemisia tabaci
(American Phytopathological Society, 2015-05-04) Jeremiah, S.; Ndyetabula, I.; Mkamilo, G.; Haji, S.; Muhanna, M.; Chuwa, C.; Kasele, S.; Bouwmeester, H.; Ijumba, J.; Legg, J.
Cassava brown streak disease (CBSD) is currently the most significant virus disease phenomenon affecting African agriculture. In this study, we report results from the most extensive set of field data so far presented for CBSD in Africa. From assessments of 515 farmers’ plantings of cassava, incidence in the Coastal Zone of Tanzania (46.5% of plants; 87% of fields affected) was higher than in the Lake Zone (22%; 34%), but incidences for both zones were greater than previous published records. The whitefly vector, Bemisia tabaci, was more abundant in the Lake Zone than the Coastal Zone, the reverse of the situation reported previously, and increased B. tabaci abundance is driving CBSD spread in the Lake Zone. The altitudinal “ceiling” previously thought to restrict the occurrence of CBSD to regions <1,000 masl has been broken as a consequence of the greatly increased abundance of B. tabaci in mid-altitude areas. Among environmental variables analyzed, minimum temperature was the strongest determinant of CBSD incidence. B. tabaci in the Coastal and Lake Zones responded differently to environmental variables examined, highlighting the biological differences between B. tabaci genotypes occurring in these regions and the superior adaptation of B. tabaci in the Great Lakes region both to cassava and low temperature conditions. Regression analyses using multi-country data sets could be used to determine the potential environmental limits of CBSD. Approaches such as this offer potential for use in the development of predictive models for CBSD, which could strengthen country- and continent-level CBSD pandemic mitigation strategies.
Knowledge and perception on ticks, tick-borne diseases and indigenous cattle tolerance to East Coast fever in agro-pastoral communities of Lake Zone in Tanzania
(Fundacion CIPAV, 2015-04-01) Laisser, E.; Chenyambuga, S.; Msalya, G.; Kipanyula, M.; Mdegela, R.; Karimuribo E.; Mwilawa A.; Kusiluka L.
This study was carried out to assess farmers’ knowledge and perceptions on tick species, tick-borne diseases (TBDs), tick control measures, production constraints and tolerance of Tarime and Sukuma zebu cattle to TBDs. The study involved 240 agro-pastoralists from Serengeti, Tarime, Maswa and Meatu districts in Tanzania. Data were collected through individual interview using a structured questionnaire. Livestock diseases were ranked as the first important problem affecting cattle production in Serengeti and Tarime districts while in Maswa and Meatu districts lack of livestock feeds during the dry season was ranked as the most important constraints, followed by livestock diseases. Among the diseases affecting cattle, the TBDs ranked first in Serengeti and Tarime while in Maswa and Meatu the TBDs, ranked fourth and sixth, respectively. Most of the livestock farmers interviewed (74%) knew well the signs of the TBDs. Circling/high stepping, red urine, hard dung and swollen lymph nodes were mentioned as clinical symptoms for heartwater, babesiosis, anaplasmosis and East Coast fever (ECF), respectively. The majority of the respondents in all districts knew that ECF is caused by ticks, but did not associate the other TBDs with ticks. The most prevalent ticks were bont ticks (Ambyomma spp), blue ticks (Boophilus spp) and brown ear ticks (Rhipicephalus appendiculatus). Most of the farmers interviewed were using acaricide to control ticks, and the most common method of application was hand spraying. All farmers used Oxytetracycline to treat TBDs; however, some farmers used local herbs. Although most farmers knew the signs of TBDs, they were not spraying/dipping their animals on regular basis because of economic reasons and the belief that their animals always carry ticks without being sick or dying and ECF affects only calves. About half of the farmers considered their breeds to be tolerant to ticks and ECF. In conclusion, the livestock farmers in the Lake zone have substantial knowledge on tick species and TBD symptoms and they have a perception that ECF is not the most important disease compared to the other TBDs.
Physiological and molecular characterization of drought responses and identification of candidate tolerance genes in cassava
(Oxford University Press, 2013-03-21) Turyagyenda, Laban; Kizito, Elizabeth; Ferguson, Morag; Baguma, Yona; Agaba, Morris; Harvey, Jagger; Osiru, David
Cassava is an important root crop to resource-poor farmers in marginal areas, where its production faces drought stress constraints. Given the difficulties associated with cassava breeding, a molecular understanding of drought tolerance in cassava will help in the identification of markers for use in marker-assisted selection and genes for transgenic improvement of drought tolerance. This study was carried out to identify candidate drought-tolerance genes and expression-based markers of drought stress in cassava. One drought-tolerant (improved variety) and one drought-susceptible (farmer-preferred) cassava landrace were grown in the glasshouse under well-watered and water-stressed conditions. Their morphological, physiological and molecular responses to drought were characterized. Morphological and physiological measurements indicate that the tolerance of the improved variety is based on drought avoidance, through reduction of water loss via partial stomatal closure. Ten genes that have previously been biologically validated as conferring or being associated with drought tolerance in other plant species were confirmed as being drought responsive in cassava. Four genes (MeALDH, MeZFP, MeMSD and MeRD28) were identified as candidate cassava drought-tolerance genes, as they were exclusively up-regulated in the drought-tolerant genotype to comparable levels known to confer drought tolerance in other species. Based on these genes, we hypothesize that the basis of the tolerance at the cellular level is probably through mitigation of the oxidative burst and osmotic adjustment. This study provides an initial characterization of the molecular response of cassava to drought stress resembling field conditions. The drought-responsive genes can now be used as expression-based markers of drought stress tolerance in cassava, and the candidate tolerance genes tested in the context of breeding (as possible quantitative trait loci) and engineering drought tolerance in transgenics.
Allelopathy as protectant, defence and growth stimulants in legume cereal mixed culture systems
(Taylor & Fransic Online, 2012-09) Makoi, Joachim; Ndakidemi, Patrick
In Africa, yield loss and low income to farmers is exacerbated by pests and notorious weeds manifested in different cropping systems. The fact that crop species may be allelopathic to common weeds, pathogens and insect pests has attracted considerable attention as an alternative strategy for weed and pest management in small-scale and low-input mixed culture systems. The use of crop plants with greater allelochemical production could limit the need for agrochemicals and conventional herbicides for plant protection and defence. As a result, plant growth and grain yield will be increased, leading to greater profit margins for farmers. This review discusses the possible role(s) of allelopathy as a key player in protection, defence and growth stimulants in legume cereal intercropping systems. © 2012 The Royal Society of New Zealand.
Prevalence and Determinants of Undernutrition in Schoolchildren in the Kilombero District, South-Eastern Tanzania
(MDPI, 2024-04-25) Minja, Elihaika; Mrimi, Emmanuel; Mponzi, Winfrida; Mollel, Getrud; Lang, Christin; Beckmann, Johanna; Gerber, Markus; Pühse, Uwe; Long, Kurt; Masanja, Honorat; Okumu, Fredros; Finda, Marceline; Utzinger, Jürg
Childhood undernutrition is a major issue in low- and middle-income countries, affecting the health, well-being, and educational outcomes of schoolchildren. This study aimed to assess the prevalence and associated factors of stunting, wasting, and underweight among schoolchildren in peri-urban areas in the south-eastern part of Tanzania. A cross-sectional study was conducted involving 930 children aged 6–12 years from four primary schools from July to August 2019. The WHO Anthro Survey Analyzer was employed to estimate the prevalence of stunting, wasting, and underweight, while logistic regression analyses examined sociodemographic background, malaria infection, anaemia, anthropometric measures, and dietary diversity score as potential factors. The prevalence of stunting, wasting, underweight, overweight, and obesity was 11.8%, 4.3%, 3.9%, 11.1%, and 2.0%, respectively. Overall, 1.5% of the children had malaria, as determined by rapid diagnostic tests, and 0.4% had severe anaemia. Univariate analysis indicated higher odds of undernutrition among children aged 9–12 compared to their younger peers. Stunting was more common among children with low and medium dietary diversity. Anaemia was found in 11.2% of schoolchildren, and severe anaemia was associated with wasting. Multivariate analysis revealed that age and low dietary diversity were significantly associated with undernutrition. These findings emphasise the need for school-based health and nutrition programmes targeting children beyond the age of 5 to improve their nutritional status and mitigate potential adverse effects on health, cognition, and academic achievement. Regular assessment of the nutritional status of schoolchildren is warranted.
Characterization of Yield and Physico-Chemical Parameters of Selected Wild Indigenous Fruits in Rwanda
(MDPI, 2024-07-22) Nishimwe, Gaudence; Augustino, Suzana; Dahlin, Anna; Niyitanga, Fidèle
A study was carried out to assess the physico-chemical characteristics of wild fruits: Myrianthus holstii and Garcinia buchananii, consumed by rural communities in Rwanda. Although the species have been prioritized for domestication in the country, very little information has been documented on their yield potential, morphological traits, and nutritional compositions. Data were collected from nine fruiting trees for each species in the Bugesera and Nyamagabe districts. All fruits per tree were counted and 10 fruits were harvested for characterization. The proximate composition, vitamins, and minerals were analyzed using Association of Official Analytical Chemists (AOAC) methods. Analyses of inferential statistics were performed to detect differences in means among the fruits from different populations. The highest yield (279 kg/tree) for M. holstii was recorded in the Musebeya population while the highest (15.12 kg/tree) for G. buchananii was recorded in the Juru populations. The quantities of vitamins A and C in M. holstii fruits ranged from 0.92 mg/100 g to 0.93 mg/100 g and from 19.22 mg/100 g to 19.94 mg/100 g, respectively. The quantities of vitamins A and C in G. buchananii fruits ranged from 0.56 mg/100 g to 0.95 mg/100 g and 33.82 mg/100 g to 34.84 mg/100 g, respectively. The most abundant mineral element recorded in this study was iron (15.95 mg/100 g) found in the M. holstii species and contributing 159.5% of the recommended daily allowance. The results obtained in this work suggest the potential value of G. buchananii and M. holstii for the development of novel products in the food industry. The findings also offer opportunities for tree selection to support their domestication and to reduce pressure on the remaining population in the wild.
Dietary Exposure of Infants and Young Children to Aflatoxinand Fumonisins in the East African Region: A Review
(Current Research in Nutrition and Food Science, 2024-06-06) Kayanda, Rosemary; Ngure, Francis; Kassim, Neema
Proper supplementary nutrition is essential for nurturing and promoting the growth and development of Infants and Young Children (IYC). Poor food quality and safety during this critical period can result in malnutrition. Complementary foods (CF) commonly provided to IYC in East African countries often contain ingredients highly susceptible to mycotoxin contamination, particularly aflatoxins (AFs) and fumonisins (FBs). This narrative review sought to explore the contamination of infant diets with AFs and FBs, as well as the exposure of IYC to these toxins. The review covers the types of CF used in infant diets, their susceptibility to AFs and FBs contamination, associated dietary exposure, and detection methods, along with regulatory and mitigation strategies in the East Africa region. Studies revealed widespread contamination of staple crops with AFs and FBs, highlighting that IYC primarily encounter these toxins through the consumption of cereal-based CF, often supplemented with legumes and oily seeds. Maize and groundnuts emerge as the predominant ingredients in CF. Despite established regulatory limits for these toxins in food intended for the general population, no specific limits exist for IYC, who are particularly vulnerable due to their high consumption of the susceptible crops and relatively small body size. Limited enforcement of existing regulations, unfortunately, allows the problem to persist in these low-resource countries. Focusing on East Africa, this review synthesizes findings from scientific studies to assess the dietary exposure of children to AFs and FBs through CFs. The findings underscore the need for further research on the magnitude and effects of AFs and FBs exposure, coupled with awareness campaigns to promote the demand for clean and safe CF within the East African Community countries.
Domestication of wild indigenous fruit trees in Rwanda: Perspectives from rural communities
(Elsevier Ltd., 2024-07-14) Nishimwe, Gaudence; Dahlin, A. Sigrun; Niyitanga, Fidèle; Augustino, Suzana
Wild indigenous fruit trees (WIFTs) play a vital role in food and nutritional security in sub-Saharan Africa. However, these resources are currently less accessible to rural populations due to the expanding arable lands and over-exploitation of the trees in the wild, which lead to a decline in their population. This study (i) explored the availability and uses of WIFTs in the Nyamagabe and Bugesera districts of Rwanda (ii) identified challenges and potential interventions for domestication of WIFTs, (iii) assessed community perceptions on WIFTs domestication primarily as integrated system components in smallholder's farm (iv) and also determined the priority species for domestication. A total of 380 respondents from Bugesera and Nyamagabe districts were interviewed using a semi-structured questionnaire. Data were analyzed descriptively using the SPSS software analysis tools. Results revelaled a total of 19 WIFTs, 15 from the Bugesera district, and five from the Nyamagabe district with one species occurring in both districts. The recorded WIFTs were used mainly as food, medicine and fuel wood. Despite a decline in population locally, most respondents were interested in domesticating WIFTs and expressed willingness to integrate them on their farmlands once the planting materials are availed. From the study a suggestion to promote the domestication of the priority WIFTs through a collaborative initiative between the Ministry of Agriculture and Animal Resources, research institutions and other stakeholders is important. This will ensure not only the sustainability of the WIFTs species to communities but also contribute to their socio-economic development once the products are developed through proper value chains addition.
Societal uses of the main water bodies inhabited by malaria vectors and implications for larval source management
(Springer Nature, 2024-11-09) Kahamba, Najat; Tarimo, Felista; Kifungo, Khamisi; Mponzi, Winifrida; Kinunda, Siaba; Simfukwe, Alfred; Mapua, Salum; Msugupakulya, Betwel; Baldini, Francesco; Ferguson, Heather; Okumu, Fredros; Finda, Marceline
Background: Larval source management (LSM) effectively reduces mosquito populations at their breeding sites, addressing issues like insecticide resistance that limit the effectiveness of primary interventions such as insecticide-treated nets (ITNs). Although traditionally used in urban and dry areas, recent research suggests it might also be effective in rural settings in eastern and southern Africa, where Anopheles funestus thrives in permanent water bodies that sustain year-round transmission. Targeting these habitats could enhance LSM, but it requires understanding local community practices, as mosquito breeding sites often overlap with community water resources. This study examined how communities use aquatic habitats and how these practices may impact LSM strategies, with a focus on habitats used by An. funestus. Methods: This study was conducted in three villages in the Ulanga and Malinyi districts of southeastern Tanzania using a mixed-methods approach. Quantitative data were collected through cross-sectional surveillance, and qualitative data through unstructured interviews, focus group discussions, and field observations. Data analysis integrated both quantitative and qualitative findings to develop a comprehensive understanding of community perspectives. Results: A survey of 931 aquatic habitats found mosquito larvae in 73% of them, with late instar An. funestus present in 23%. River streams made up 41% of the habitats, while ground pools accounted for 4%. Most habitats (90%) were used by communities, including 95% of those with An. funestus larvae, for activities such as domestic chores, agriculture, livestock rearing, brickmaking, and fishing. Focus group discussions revealed a willingness to adopt LSM, with a preference for larviciding and habitat modification over habitat removal, as the water sources were vital for daily use. Community concerns centered on the safety of larvicides for humans and animals, the environmental impact, and the need for better awareness of how LSM affects health and livelihoods. Conclusion: This study highlights community perspectives on LSM, focusing on the dual function of aquatic habitats as mosquito breeding sites and essential community water sources. This dual role presents both challenges and opportunities, suggesting that LSM strategies must balance public health needs with socio-economic realities. There was a clear preference for larviciding and habitat modification over removal, with a strong emphasis on health and environmental safety. The study emphasizes the importance of educating communities on the safety and effectiveness of LSM, and tailoring LSM strategies to fit the needs and preferences of local communities.

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