scholarly journals Genetic Analysis of New Maize Hybrids for Yield and Resistance to Aflatoxin Accumulation

2021 ◽  
Vol 13 (10) ◽  
pp. 15
Author(s):  
Allen Oppong ◽  
Abu M. Dadzie ◽  
Beatrice Ifie ◽  
Maxwell D. Asante ◽  
Ruth N. A. Prempeh ◽  
...  

Maize (Zea mays L.) is the most important cereal crop in sub-Saharan Africa providing food for many of its inhabitants. However, production is hampered by low yields and aflatoxin contamination, among others. The toxin contaminates maize before harvest and during storage. Ghana lacks regulatory infrastructure for monitoring and detecting aflatoxin in grains prior to market, and most of the local maize varieties have been found to be susceptible to aflatoxin accumulation. Host resistance is envisaged as a key approach in addressing the aflatoxin menace. Thus, this study was conducted to identify new hybrids that combine high yield with resistance to aflatoxin accumulation as well as study the mode of gene controlling tolerance to aflatoxin accumulation. Sixteen aflatoxin resistant inbreds from exotic sources were crossed as males to 10 local germplasm in a North Carolina II design to generate 160 new hybrids. These were planted together with 9 checks using a 13 × 13 alpha lattice with three replications. The new hybrids were evaluated across six environments in two seasons. Five plants each per hybrid were inoculated with a local strain of Aspergillus flavus at a concentration of 9 × 107conidia/ml. Ninety-six out of the 169 crosses were analyzed statistically. Significant effect of environment and genotypes for all traits especially, for aflatoxin accumulation resistance and yield were observed. The general combining ability effect of males for all traits were found significant (P < 0.05) whereas that of the females were not significant for all traits. Inbreds with consistent significant negative GCA effect for aflatoxin reduction were identified (MP715, TZI8, MP719). Furthermore, the underlying genetic control for the aflatoxin accumulation resistance trait was found to be via both GCA and SCA effects. Heritability estimates were moderate, suggesting permissible transfer of traits during selection to create high yielding aflatoxin resistant hybrids for consumers.

2016 ◽  
Vol 79 (5) ◽  
pp. 795-800 ◽  
Author(s):  
SAMUEL M. C. NJOROGE ◽  
LIMBIKANI MATUMBA ◽  
KENNEDY KANENGA ◽  
MOSES SIAMBI ◽  
FARID WALIYAR ◽  
...  

ABSTRACT A 3-year comprehensive analysis of aflatoxin contamination in peanut butter was conducted in Zambia, sub-Saharan Africa. The study analyzed 954 containers of 24 local and imported peanut butter brands collected from shops in Chipata, Mambwe, Petauke, Katete, and Nyimba districts and also in Lusaka from 2012 to 2014. For analysis, a sample included six containers of a single brand, from the same processing batch number and the same shop. Each container was quantitatively analyzed for aflatoxin B1 (AFB1) in six replicates by using competitive enzyme-linked immunosorbent assay; thus, aflatoxin contamination level of a given sample was derived from an average of 36 test values. Results showed that 73% of the brands tested in 2012 were contaminated with AFB1 levels >20 μg/kg and ranged up to 130 μg/kg. In 2013, 80% of the brands were contaminated with AFB1 levels >20 μg/kg and ranged up to 10,740 μg/kg. Compared with brand data from 2012 and 2013, fewer brands in 2014, i.e., 53%, had aflatoxin B1 levels >20 μg/kg and ranged up to 1,000 μg/kg. Of the eight brands tested repeatedly across the 3-year period, none consistently averaged ≤20 μg/kg. Our survey clearly demonstrates the regular occurrence of high levels of AF B1 in peanut butter in Zambia. Considering that some of the brands tested originated from neighboring countries such as Malawi, Zimbabwe, and South Africa, the current findings provide a sub-Saharan regional perspective regarding the safety of peanut butter.


2015 ◽  
Vol 8 (2) ◽  
pp. 253-257 ◽  
Author(s):  
A. Ayeni

Sub-Saharan Africa (SSA) is the most vulnerable region of the world to all aflatoxin-related problems including food insecurity, ill health and reduced foreign exchange earnings. Aflatoxin-contaminated maize, groundnuts (peanuts), sorghum and other crops reduce human access to adequate calories from these staples; consumption of aflatoxin-contaminated foods results in severe health conditions, including liver cancer, that deny the region a significant amount of otherwise productive man-hours; while the reduction of grain quality below the international standards due to aflatoxin contamination drastically reduces income in foreign exchange earnings. Scientific knowledge of the causes of aflatoxins in agricultural systems and their mitigation abounds in research institutions in SSA and internationally, but most of this knowledge is unavailable to farmers, food consumers and policy makers in useful form due to poor extension education and ineffective extension services. A paradigm shift in the approach to extension in SSA is proposed, one driven by a sustainable mechanism that is sensitive to the needs of the people and proactive (rather than reactive) in providing solutions to aflatoxin-related problems the local community and policy makers have to deal with. This paper argues that such sustainable mechanism may only be found in a University-based and University-run ‘land grant’ type extension services adapted appropriately to SSA conditions.


2016 ◽  
Vol 9 (5) ◽  
pp. 771-789 ◽  
Author(s):  
R. Bandyopadhyay ◽  
A. Ortega-Beltran ◽  
A. Akande ◽  
C. Mutegi ◽  
J. Atehnkeng ◽  
...  

Aflatoxin contamination of crops is frequent in warm regions across the globe, including large areas in sub-Saharan Africa. Crop contamination with these dangerous toxins transcends health, food security, and trade sectors. It cuts across the value chain, affecting farmers, traders, markets, and finally consumers. Diverse fungi within Aspergillus section Flavi contaminate crops with aflatoxins. Within these Aspergillus communities, several genotypes are not capable of producing aflatoxins (atoxigenic). Carefully selected atoxigenic genotypes in biological control (biocontrol) formulations efficiently reduce aflatoxin contamination of crops when applied prior to flowering in the field. This safe and environmentally friendly, effective technology was pioneered in the US, where well over a million acres of susceptible crops are treated annually. The technology has been improved for use in sub-Saharan Africa, where efforts are under way to develop biocontrol products, under the trade name Aflasafe, for 11 African nations. The number of participating nations is expected to increase. In parallel, state of the art technology has been developed for large-scale inexpensive manufacture of Aflasafe products under the conditions present in many African nations. Results to date indicate that all Aflasafe products, registered and under experimental use, reduce aflatoxin concentrations in treated crops by >80% in comparison to untreated crops in both field and storage conditions. Benefits of aflatoxin biocontrol technologies are discussed along with potential challenges, including climate change, likely to be faced during the scaling-up of Aflasafe products. Lastly, we respond to several apprehensions expressed in the literature about the use of atoxigenic genotypes in biocontrol formulations. These responses relate to the following apprehensions: sorghum as carrier, distribution costs, aflatoxin-conscious markets, efficacy during drought, post-harvest benefits, risk of allergies and/or aspergillosis, influence of Aflasafe on other mycotoxins and on soil microenvironment, dynamics of Aspergillus genotypes, and recombination between atoxigenic and toxigenic genotypes in natural conditions.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1345
Author(s):  
Nomathemba Gloria Majola ◽  
Abe Shegro Gerrano ◽  
Hussein Shimelis

Bambara groundnut (Vigna subterranea [L.] Verdc.) is a nutritionally rich grain legume crop indigenous to Africa. It is tolerant to drought stress and has become adapted to grow under low input and marginal agricultural production systems in Africa and Asia. Bambara groundnut is an orphan crop, and represents a neglected and under researched plant genetic resource. Modern crop management, production technologies, and value chains are yet to be developed in Africa to achieve the potential economic gains from Bambara groundnut production and marketing. In sub-Saharan Africa (SSA) the production and productivity of Bambara groundnut is low and stagnant because of diverse abiotic and biotic stresses and socio-economic constraints. Improved crop management and post handling technologies, modern varieties with high yield and nutritional quality, value addition, and market access are among the key considerations in current and future Bambara groundnut research and development programs. This paper presents progress on Bambara groundnut production, utilization, and genetic improvement in SSA. It presents the key production constraints, genetic resources and analysis, breeding methods and genetic gains on yield, and nutritional quality and outlook. The information presented will guide the sustainable production and effective breeding of the crop in order to pursue food and nutrition security, and improve livelihoods through Bambara groundnut enterprises.


Author(s):  
Kindie Tesfaye ◽  
Sika Gbegbelegbe ◽  
Jill E Cairns ◽  
Bekele Shiferaw ◽  
Boddupalli M Prasanna ◽  
...  

Purpose – The purpose of this study is to examine the biophysical and socioeconomic impacts of climate change on maize production and food security in sub-Saharan Africa (SSA) using adapted improved maize varieties and well-calibrated and validated bioeconomic models. Design/methodology/approach – Using the past climate (1950-2000) as a baseline, the study estimated the biophysical impacts of climate change in 2050 (2040-2069) and 2080 (2070-2099) under the A1B emission scenario and three nitrogen levels, and the socioeconomic impacts in 2050. Findings – Climate change will affect maize yields across SSA in 2050 and 2080, and the extent of the impact at a given period will vary considerably between input levels, regions and maize mega environments (MMEs). Greater relative yield reductions may occur under medium and high-input intensification than under low intensification, in Western and Southern Africa than in Eastern and Central Africa and in lowland and dry mid-altitude than in highland and wet mid-altitude MMEs. Climate change may worsen food insecurity in SSA in 2050 through its negative impact on maize consumption and reduction in daily calorie intake. However, international trade has the potential to offset some of the negative impacts. Originality/value – The study calibrated and applied bioeconomic models to estimate the biophysical and socioeconomic impact of climate change on maize production at fine resolution. The results could be used as a baseline to evaluate measures that will be applied to adapt maize to the future climate in SSA.


2020 ◽  
Vol 28 (2) ◽  
pp. 195-202
Author(s):  
E.K. Aklaku ◽  
E.N.K. Sowley ◽  
M. Ofosu

Maize (Zea mays L.) is an important staple food crop and a source of income to farmers, as well as foreign exchange earner in most countries in sub-Saharan Africa. Its production is hampered by fungal diseases, which also cause contamination with mycotoxins, especially aflatoxin and its associated health hazards. This study sought to isolate and identify aflatoxigenic fungi, as well as detect the presence of Aflatoxin B1 (AfB1) in maize samples obtained from farmers in the Tolon-Kumbungu district in the northern region of Ghana. Twenty farming communities were randomly selected for the study in consultation with the district office of the Ministry of Food and Agriculture (MoFA). Samples were collected from 200 randomly selected maize farmers by the composite sampling technique, for isolation of aflatoxigenic fungi by the agar plate method and the detection of aflatoxin. Aflatoxin was detected in maize samples with the Black light, rapid screening and immunoassay methods. Aspergillus flavus had the highest percentage of occurrence (63.7%); followed by A. niger (16.5%), Rhizopus stolonifer (9.3%), Penicillium spp. (6.9%) and Fusarium oxysporum (3.7%). Farm samples had more aflatoxin than those from stores and markets. Samples of maize from farms in Gbirimani community had the highest aflatoxin contamination of +60 ppb. Concentrations of Afb1 at or above +20 ppb were recorded in all the communities, except in Tinguli. Apart from Voggu, all market samples were free from aflatoxin contamination. Key words: Aflatoxigenic fungi, postharvest, Zea mays


2021 ◽  
Vol 13 (1) ◽  
pp. 10691
Author(s):  
Paul INYANG ◽  
Chikezie O. ENE ◽  
Ankrumah EMMANUEL ◽  
Uchechukwu P. CHUKWUDI ◽  
Ugochukwu N. IKEOGU

Reduced water resources in sub-Saharan Africa will not only pose threat to the livelihood of poor resource farmers, but also food security in the region. Drought tolerant (DT) maize varieties hold promise to reducing poor resourced farmers’ vulnerability and improve food security in sub-Saharan Africa. Ten maize genotypes obtained from the International Institute of Tropical Agriculture (IITA), were evaluated in 2015 and 2016 using a randomized complete block design experiment with three replications to estimate their genetic variability and predict their genetic advances in the derived savannah agro-ecology. Growth, phenological and yield data were collected from 10 middle row plants. Genetic advance, genotypic, phenotypic and environmental coefficients of variations and their variances were estimated. Principal component and hierarchical cluster analyses were also performed. The dendrogram showed that at 80% dissimilarity point, the genotypes were grouped into clusters A, B and C in both years. The first two principal components explained 91.8% and 93.3% of the total variation in 2015 and 2016, respectively. Number of grains cob-1, plant height and number of days to physiological maturity were consistent in explaining the variations observed in the maize population. Heritability estimates in broad sense ranged from 1.35% for number of leaves to 87.43% for grain yield per hectare. The genetic parameters studied showed significant variations among the growth, phenological and yield data collected that warrants selection and maize improvement program using the DT maize inbred lines in derived savannah agro-ecology.


Sign in / Sign up

Export Citation Format

Share Document