21 research outputs found

    The Predictive Validity of Form Two Secondary Education Examination (FTSEE) on Students’ Performance in the Certificate of Secondary Education Examination (CSEE) in Biology Subject: A Tanzanian Perspective

    Get PDF
    This article is based on the study which sought to examine the predictive validity of Form Two Secondary Education Examination (FTSEE) on students’ performance in the Certificate of Secondary Education Examination (CSEE) in Biology subject. A sample of 120 students from some selected secondary schools in Morogoro Municipality, Tanzania, was involved. The collected data were analyzed using computer software, Statistical Package for Software System (SPSS), Version 18. In the data analysis, the Pearson’s Product-Moment Correlation (r) technique was used in order to determine the strength, direction and significance o of the relationships of all the variables included in the study. The findings indicated that there was a strong relationship between the students’ performance in the FTSEE and CSEE (i.e. from r=0.442, p<0.01 to r=0.726, p<0.01) regardless of sex and type of school. Nevertheless, the relationship was found to be higher for females (r=0.726) than males (r= 0.613). In addition, for the case of the studied Day school, male students in the Day school  had a higher correlation coefficient between the two examinations (r=0.65) than female students (r=0.442). This implies that female students performed slightly better than males in Boarding schools while in the Day school, male students performed better than females. Therefore, on the basis of these findings, it is recommended that the FTSEE should be sustained in order to improve the students’ performance in the CSEE in Tanzania.   Keywords: Predictive validity, Examinations, Students’ performance, Tanzania

    Incorporation of resistance to angular leaf spot and bean common mosaic necrosis virus diseases into adapted common bean (Phaseolus vulgaris L.) genotype in Tanzania

    Get PDF
    Angular leaf spot (ALS) caused by the fungus Pseudocercospora griseola and Bean common mosaic and necrosis virus (BCMV/BCMNV) are important diseases of common bean in Tanzania that can cause severe yield reduction when uncontrolled. This study was conducted to incorporate resistant genes for ALS and BCMV/BCMNV diseases into adapted, market class and farmers and consumers preferred bean genotype using marker assisted selection. The parents Mexico 54 and UBR(25)95 donor of Phg-2 and I/bc-3 genes for ALS and BCMV/BCMNV, respectively were used for the recipient being Kablanketi. In selection, SCAR markers SNO2, ROC11 and SW13 linked to Phg-2, bc-3 and I gene, respectively were used. A parallel backcrossing (modified double cross) procedure was used. The F1, F2 and backcrosses from single crosses were characterized. The Chi square values for ALS were 0.081 (P<0.776) and 0.017 (P<0.896) and for BCMNV were 1.609 (P<0.205) and 1.2 (P<0.273) for molecular and phenotypic screening, respectively. The resistance to ALS and BCMNV was found to be monogenic and the genes involved are dominant and recessive, respectively. The heritability of ALS was found to be high (0.772) implying that selection for ALS can be done early in segregating populations. High correlation values, r = 0.741 and 0.624 for ALS and BCMNV, were obtained between phenotypic and molecular data, indicating high reliability for markers. In selection, it was possible to select lines with multiple disease resistances. This work signified the use of MAS for multiple gene screening.Keywords: Common bean, Pseudocercospora griseola, marker assisted selection, genotype, inheritanceAfrican Journal of Biotechnology Vol. 12(27), pp. 4343-435

    NATURE OF RESISTANCE OF COWPEA ALECTRA VOGELII INFESTATION

    Get PDF
    Alectra vogelii (benth) is parasitic weed which causes significant yield reductions in cowpea ( Vigna unguiculata Walp) in Africa. The objective of this study was to identify the type of gene action controlling the trait for resistance to Alectra vogelii in cowpea and estimate the heritability of the trait. Seven genotypes of cowpea were mated in half diallel and their F2 progeny, including parents, were evaluated for reaction to Alectra vogelii infection in the field in two locations at Ilonga and Hombolo Agriculture Research Stations. Highly significant (P < 0.001) differences were found for Alectra emergency and infestation at Ilonga. General combining ability (GCA) and specific combining ability (SCA) effects for Alectra shoot emergency and infestation were significant (P < 0.05). The estimate of Baker\u2019s ratio for Alectra shoot emergency and infestation were 0.62 and 0.66, respectively. This indicates that both additive and non-additive gene actions influenced the trait for resistance to Alectra emergency and infestation. Narrow sense heritability estimates were 41.28 and 44.39 for shoot and emergency, respectively. These results imply that introgression of a desirable trait in an elite genotype would involve careful crossing with a resistance genotype, accompanied by selection in the advanced population.Alectra vogelii (benth) est une herbe parasite qui engender des reductions significatives dans les rendements du ni\ue9b\ue9 ( Vigna unguiculata Walp) en Afrique. L\u2019objectif de la pr\ue9sente \ue9tude \ue9tait d\u2019identifier le type d\u2019action de g\ue8ne controllant la r\ue9sistance \ue0 Alectra vogelii chez le ni\ue9b\ue9 et d\u2019estimer les valeurs d\u2019h\ue9ritabilit\ue9. Sept g\ue9notypes de ni\ue9b\ue9 ont \ue9t\ue9 crois\ue9s selon le mode half diallel et leurs descendants F2, ainsi que les parents, ont \ue9t\ue9 \ue9valu\ue9s pour leur reaction face \ue0 \u2018linfestation en plein champs du Alectra vogelii dans les stations de recherch\ue9 agricole de Ilonga et Hombolo. Des differences tr\ue8s significatives (P < 0,001) ont \ue9t\ue9 observ\ue9es pour l\u2019\ue9mergence, la croissance v\ue9g\ue9tative et l\u2019infestation de Alectra \ue0 Ilonga. L\u2019habilet\ue9 \ue0 la combinaison g\ue9n\ue9rale (GCA) et sp\ue9cifique (SCA) pour l\u2019\ue9mergence, la croissance v\ue9g\ue9tative et infestation de Alectra \ue9taient significative (P < 0,05). les valeurs du ratio de Baker pour l\u2019\ue9mergence, la croissance v\ue9g\ue9tative et l\u2019infestation de Alectra \ue9taient respectivement de 0,62 et 0,66. Ceci indique que les deux effets de g\ue8ne; additif et non-additif sont responsables de la r\ue9sistance \ue0 l\u2019\ue9mergence, la croissance v\ue9g\ue9tative et \ue0 l\u2019infestation de Alectra. Les valeurs de l\u2019h\ue9ritabilit\ue9 au sens strict \ue9taient respectivement de 41,28 et 44,39 pour la croissance v\ue9g\ue9tative et l\u2019\ue9mergence. Ces r\ue9sultats indiquent que l\u2019introgression d\u2019un caract\ue8re d\ue9sirable dans un g\ue9notype \ue9lite n\ue9cessiterait des croisements avec un genotype r\ue9sistant, suivi de selection au cours des g\ue9n\ue9rations avanc\ue9es

    Traditional African Vegetables Agrobiodiversity: Livelihood Utilization and Conservation in Tanzania Rural Communities

    Get PDF
    The agricultural sector is challenged to fulfill the nutritional requirements of ever-increasing population. Rates of growth in crop productivity have declined, among many reasons is due to climate change and the decline of water and land resources. Dependence by 50% on few cereal crops like wheat, maize and rice for total food intake and calorie requirements has countersigned loss of biodiversity and decline in crop productivity. The genetic diversity of traditional crop varieties offers resilience to environmental risks, socioeconomic shocks, adaptation and mitigation to climate change which is crucial for crop production. Traditional African Vegetables (TAVs) are an integral constituent of the diets of many rural and urban communities. They are important sources of essential macro and micro-nutrients. In addition, they offer a source of livelihood when marketed, and also contribute to crop biodiversity. Tanzania needs to conserve the Traditional African vegetables and their genetic resources against stressful conditions and increased selection pressures which causes loss of genetic variation and a decrease in fitness by a process called genetic erosion. Conservation and use alleviate genetic drift and inbreeding depression, then, is critical to guarantee TAVs persistence in rural areas. This review explores agrobiodiversity of traditional African vegetables (TAV) from livelihood of Tanzanian rural communities’ perspectives and how the country has managed to conserve these species

    Nutritionally Enhanced Staple Food Crops

    Get PDF
    Crop biofortification is a sustainable and cost-effective strategy to address malnutrition in developing countries. This review synthesizes the progress toward developing seed micronutrient-dense cereals and legumes cultivars by exploiting natural genetic variation using conventional breeding and/or transgenic technology, and discusses the associated issues to strengthen crop biofortification research and development. Some major QTL for seed iron and zinc, seed phosphorus, and seed phytate in common bean, rice,J;md wheat have been mapped. An iron reductase QTL associated with seed-iron ~QTL is found in common bean where the genes coding for candidate enzymes involved in phytic acid synthesis have also been mapped. Candidate genes for Ipa co segregate with mutant phenotypes identified in rice and soybean. The Gpe-B1 locus in wild emmer wheat accelerates senescence and increases nutrient remobilization from leaves to developing seeds, and another gene named TtNAM-B1 affecting these traits has been cloned. Seed iron-dense common bean and rice in Latin America; seed iron-dense common bean in eastern and southern Africa;....

    Determinants of Digital Transformation in Sub-Saharan Africa: Some Fiscal Policy Implications

    No full text
    The study examines the determinants of digital transformation by using panel data of 35 countries in sub-Sahara Africa (SSA) for the period 2014–2021. Based on the fixed effect model, the findings established network coverage, ownership of mobile phones, adult literacy rate, and income were positive and significant determinants of internet use in SSA. The empirical findings suggest governments in SSA countries should nurture potential of the internet in the drive to inclusive economic growth and development, as well as digital transformation. To that effect, they should promote investment in internet infrastructure, digital literacy, and refrain from taking actions that would undermine the transformative potential of digital technologies. In relation, the SSA governments could, among others, suspend value-added tax (VAT) on low-end smartphones to render them affordable for low-income earners; and, establish a Universal Service Fund for subsidizing access to lower-cost smartphones in rural areas that are newly connected to 3G and 4G networks; and pay for a subsidized public Wi-Fi hotspot. The SSA government, individually or under the public-private partnership (PPP), could get involved in parts of the value chain of smartphones – including marketing, distribution, and retail
    corecore