Hormonal influence on the in vitro bud burst of some cassava varieties and accessions from Benin

This work tested the effect of different growth regulators on Manihot esculenta explants cultured. Nodal segments were disinfected and cultivated on Murashige and Skoog’s basal media. The effects of the different combinations on bud burst were observed after five weeks of culture. The results show an interaction between the growth regulators and the genotypes of the varieties and accessions. Most of the varieties and accessions (Gbèzé, Kpètévikoutou, Ibadan and Sèkandji) obtained the maximal bud burst in the media MS supplemented with 0.2 mg/l BAP and MS supplemented with 0.2 mg/l KIN. However, with segments cultivated in medium, containing 0.2 mg/l KIN, 1 in 15 showed bud burst for the accession Agric Comé. Naphthalene acetic acid effect varied according to the genotype and the cytokinin used, whereas on 0.1 mg/l NAA combined with 0.2 mg/l with the variety 92/0057, 14 in 15 budded. However, no bud burst was observed with 0.1 mg/l NAA combined with 0.2 mg/l BAP.Keywords: In vitro culture, Manihot esculenta Crantz, bud burst, NAA, BAP, KinetinAfrican Journal of Biotechnology Vol. 12(13), pp. 1475-148

Diversité Variétale, Qualité Et Utilisation Du Maïs (Zea Mays) En Afrique De l’Ouest : Revue Critique

Maize (Zea mays) is a cereal cultivated through all the region of the world. Its constitutes one of the cereals the most used for human consumption. The current review focused on the diversity, the nutritional quality and the forms of use of maize in West Africa region. The review allowed to notice that more than twenty varieties of maize were cultivated in Bénin and in the sub-region. With regard to nutritional aspect, those different varieties of maize contained variable amounts of starch (64-78%), fat (4- 6%), protein (7-12%), crude fibers (2-2.5%), ash (1-1.5%) and sugar (1-3%). Potassium (324.8-344 mg /100g), magnesium (107.9-115 mg/100g) and phosphorus (99,6-276 mg/100g) were the main mineral in maize. Likewise, leucine, isoleucine, tryptophane and valine all contained in the germ were the main amino acids in maize. These chemical components can be alone or in a possible synergy of action responsible for numerous technological advantages of maize. Through its chemical and technological characteristics the maize constitutes an important raw material for many culinary recipes in West Africa region. So it is important to make the inventory of the main varieties cultivated in the sub-region, to compare them at both nutritional and technological aspects for prospective actions to undertake in order to improve the yield of these varieties and to guarantee food security for the populations

Evaluation of the Mixed Effects of Some Indigenous Strains of Arbuscular Mycorrhizal Fungi on the Growth of Maize Seedlings Under Greenhouse Conditions

The objective of the study was to evaluate the joint effects of three groups of native arbuscular mycorrhizal fungi (AMF) (Glomeraceae, Acaulosporaceae and Diversisporaceae) on the growth of Maize Seedlings. The mycorrhizal fungi were isolated by the wet sieving method through decreasing sieve (300 µm, 125 µm, 63 µm and 38 µm) followed by centrifugation on a sucrose gradient. The growth tests were evaluated in greenhouse conditions for 40 days. After opening a planting hole, two maize (2000 SYNEE-W) seeds, one coated with AMF and the other not coated (Control) were introduced into the planting hole for each treatment. Data on different parameters were evaluated. The results of this study revealed that the maximum heights, the largest noose diameters and the largest numbers of leaves were obtained with treatment "Acaulosporaceae + 50% NPK-Urea" having 20.55% and 17.04% respectively and 11.77% for that of the control. The produced biomass and the leaf area of the maize plants were improved by the treatment "Glomeraceae+ 50NPK-Urea" with a respective increase of 54.97% for fresh above biomass (FAB), 42.94% for fresh underground biomass (FUB) and 55.23% for the leaf area compared with the control. Also, very high frequency of mycorrhiza was recorded with treatment "Glomeraceae" while the largest numbers of mycorrhiza spores and intensity were recorded with treatment "Acaulosporaceae". These results augur the possibility of using these mixed AMF bio-products as organic fertilizers to improve maize productivity in Benin

Correlation Between Iodine Status and Dysfunctional Parameters of the Thyroid Gland of Djidja Schoolchildren

Iodine is reported to be one of the main trace mineral constituting thyroid hormones. The aim of this study was to determine the correlation between urinary iodine concentration status and dysfunctional parameters of the thyroid gland of schoolchildren in central Benin. In our study we selected 108 schoolchildren to whom we performed T3, T4, TSH, iodine and thyroid volume tests. The determination of the morning urinary iodine (iodine) in Djidja schoolchildren gave satisfactory results to 72% thus declaring our study area as a zone of non-iodine dietary deficiency. The hormone assay results are favorable at a rate of 92% and corresponds to hypothyroidism. In fact, TSH are high in 85% of the study population, T3 are in their case low in 93% of our study population and finally T4 are lower in the 100% of individuals in the study population. But these results are not in agreement with the iodine obtained. Indeed, in the study environment, the population is forced to drink some water rich in fluoride. Fluorine is an iodine antagonist that it can easily substitute, disrupting the production of T3, T4 and TSH hormones. To end, the calculated thyroid echography volumes are for the most part normal volumes with a rate of 45.37 for boys and 35.19 for girls

Effets des rhizobactéries PGPR sur le rendement et les teneurs en macroéléments du maïs sur sol ferralitique non dégradé au Sud-Bénin

L’objectif de l’étude est d’évaluer les effets de 15 rhizobactéries promotrices de croissance végétative (PGPR en Anglais) sur le rendement et l’état nutritionnel des plants de maïs sur sol ferralitique non dégradé du Sud-Bénin. Les semences de maïs ont été inoculées avec des concentrations microbiennes d’environ 108 UFC/ml. Les teneurs en azote, en phosphore et en potassium d’échantillons de plants de maïs ont été déterminées. Les valeurs de rendement du maïs ont été soumises à une analyse de la variance à deux facteurs. Les rhizobactéries Pseudomonas fluorescens ont induit le rendement de maïs le plus élevé, dépassant de 41,46% le rendement de maïs obtenu avec l’inoculation de P. putida et de 118,05% le rendement de maïs obtenu au niveau des plants non inoculés. Les rendements de maïs induits par P. putida et Azospirillium lipoferum sont supérieurs respectivement de 54,17% et de 26,39% au rendement obtenu au niveau des plants non inoculés. Les résultats obtenus augurent de la possibilité d’utiliser les rhizobactéries PGPR comme des engrais biologiques pour une production durable de maïs. Au Sud du Bénin, où la pression démographique est forte et la baisse de la fertilité des sols croissante, l’utilisation de méthodes biologiques pour accroître les récoltes est une solution incontournable.Mots clés: Rhyzobactéries, Rendement, Maïs, Sol ferralitique, Béni

Yam bean (Pachyrhizus erosus) tuber processing in Benin: production and evaluation of the quality of yam bean-gari and yam bean-fortified gari

Yam bean (Pachyrhyzus erosus) tubers were processed singly and mixed with cassava into different types of gari (100% yam bean gari, 75% yam bean gari, 50% yam bean gari and 25% yam bean gari) following the traditional gari processing method. Conventional gari from cassava was processed following the same approach and used as control. Physical characteristics, proximate composition and sensory quality of the garis obtained were assessed. Results showed that low and medium (25% and 50%) yam bean fortified gari processing yielded better than 75% and 100% yam bean gari processing. Low and medium yam bean gari were the closest to conventional gari regarding the brown index (18.0 and 18.3 respectively), had good swelling capacity (≥ 3) and had higher relative bulk density (0.57 and 0.53 respectively). The proteins content of the processed yam bean garis increased with increasing incorporation rate of yam bean but, similarly, the crude fibres content increased going beyond the recommended level of 2% maximum. The processed garis were used to cook èba which were submitted to panellists’ appreciation. Panellists scored better low and medium yam bean fortified garis and the resulting èba. Combining the results, the highest suggested incorporation rate was 50% yam bean tubers. © 2013 International Formulae Group. All rights reserved.Keywords: Legume tuber-root crop, quality, physical characteristics, chemical composition, sensory evaluation

ANTIMICROBIAL, ANTIOXIDANT, CYTOTOXIC ACTIVITIES AND PHYTOCHEMICAL ASSESSMENT OF COLA ACUMINATA USED IN BENIN

Objective: The aim of this study was to make a phytochemical screening and measure some biological activities of Cola acuminata's seeds and leaves extracts.Methods: The secondary metabolite was detected by the method based on coloring and precipitation differential reactions. The antibacterial and antifungal activities were assessed in vitro by the macrodillution and solid medium agar diffusion method. 2,2-diphényl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were used to evaluate the antioxidant activity of the tested extracts of which larval cytotoxicity was studied.Results: Our data revealed that the seeds contain more polyphenols than the leaves. The seeds extracts displayed a good antibacterial activity against both reference strains and food Staphylococcus strains. The inhibition diameters varied from 7±2.82 to 21.5±4.94 mm. The smallest Minimum Inhibitory Concentrations (MIC) on the food strains (0.08 mg/ml) is twice less than the reference strains one (0.15 mg/ml), this observation is contrary to the Minimum Bactericidal concentrations (MBC). Susceptibility of fungal strains varies according to the extracts (p = 0.0016). The seeds ethyl acetate extracts had the best antioxidant activity with DPPH and ABTS methods. The Lethal Doses (LD50) showed that no extract was toxic.Conclusion: Cola acuminata seeds are richer than the leaves in compounds with biological activities. These two organs have interesting antimicrobial, antifungal and antioxidant activity variables depending to the extracts. The seeds have better biological activity than the leaves.Â

Identification of Extended-Spectrum -Lactamases Escherichia coli Strains Isolated from Market Garden Products and Irrigation Water in Benin

The present study aimed at biochemical and molecular characterization of Escherichia coli strains isolated from horticultural products and irrigation water of Cotonou. The samples were collected from 12 market gardeners of 4 different sites. Rapid' E. coli medium was used for identification of E. coli strains and the antimicrobial susceptibility was performed by the agar disk diffusion method. The -lactamases production was sought by the liquid acidimetric method. The genes coding for -lactamases and toxins were identified by PCR method. The results revealed that about 34.95% of the analyzed samples were contaminated by E. coli. Cabbages were the most contaminated by E. coli (28.26%) in dry season. All isolated strains were resistant to amoxicillin. The penicillinase producing E. coli carried bla TEM (67.50%), bla SHV (10%), and bla CTX-M (22.50%) genes. The study revealed that the resistance genes such as SLTI (35.71%), SLTII (35.71%), ETEC (7.15%), and VTEC (21.43%) were carried. Openly to the found results and considering the importance of horticultural products in Beninese food habits, it is important to put several strategies aiming at a sanitary security by surveillance and sensitization of all the actors on the risks of some practices

Characterization of Potential Plant Growth Promoting Rhizobacteria Isolated from Maize ( Zea mays

Our study aims to characterize Plant Growth Promoting Rhizobacteria (PGPR) isolated from maize roots in five agroecological zones of central and northern Benin. Sixty samples were collected at the rate of four samples per village and three villages per agroecological zone. Rhizobacteria strains were isolated from these samples and biochemically characterized. These strains were analyzed for some of their PGPR traits like ammonia production and hydrogen cyanide following conventional methods. Microbiological investigation of these samples has shown that maize rhizospheres in central and northern Benin contain a high diversity of microorganisms. A total of nine species of maize Plant Growth Promoting Rhizobacteria were identified. Those PGPR include five Bacillus species (B. polymyxa, B. pantothenticus, B. anthracis, B. thuringiensis, and B. circulans), three Pseudomonas species (P. cichorii, P. putida, and P. syringae), and Serratia marcescens. The microbial diversity does not depend on the soil types. The microbial density, generally high, varies according to both soil types and agroecological zones. All Serratia strains (100%) have produced ammonia, whereas 80% of Bacillus and 77.77% of Pseudomonas produced this metabolite. The hydrogen cyanide was produced by all isolates (100%) independent of their genus. These results suggest the possibility to use these rhizobacteria as biological fertilizers to increase maize production

Mycorrhizal Symbiosis for Sustainable Optimization of Tropical Agriculture: A Review of Research

Excessive application of chemical fertilizers and other agrochemicals can cause significant imbalances in soils and agricultural ecosystems. To minimize these impacts, biofertilizers and organic fertilizers are needed to maintain a sustainable production system. The use of subterranean microorganisms in agriculture to stimulate plant growth and improve yields has recently received increasing interest. In this context, mycorrhizae represent a viable solution to mitigate these adverse effects. Mycorrhizal fungi are able to form a symbiotic relationship with the roots of plants in the environment. Mycorrhizal fungus helps the plant to absorb nutrients and water. In addition, mycorrhizal fungi play a crucial role in storing carbon (C) in the soil. Most previous studies have just considered the effects of AMF species on a specific crop in one particular area but have not assessed the balance of AMF in production systems in tropical agriculture. This consideration should allow for the optimization of cropping practices through a review of the work on the use of AMF in tropical agriculture production systems. In this paper, we will discuss, through different examples of experiments carried out in the tropics, the performance of different strategies for managing the potential of AMF to maintain a sustainable production system