Effects of Fusarium verticilloides, its metabolites and neem leaf extract on germination and vigour indices of maize (Zea mays L.)

Maize (Zea mays L.) seed samples were collected from three markets in Minna, Niger State to investigate the effect of Fusarium verticilloides, its metabolites and neem (Azadirachta indica) leaf ethanolic extract on germination of the seeds and seedling vigour. Among the fungi genera isolated from the seeds samples were Aspergillus spp. (41.18%), Fusarium spp. (29.41%) and Rhizopus spp. (23.53%). F. verticilloides metabolite was extracted using dichloromethane and phosphoric acid (10:1) while powdered neem leaf was extracted with ethanol for 72 h. The experiment, which was made up of eight treatments and three replicates, was set up in a germination chamber. At 9 days after sowing (9 DAS), the seeds applied with combined F. verticilloides mycelia and their metabolites had the least germination percentage (30%), the highest rot-index (3.5) and the least seedling vigour (0.93). The seedsapplied with neem extract only had the highest germination percentage of 100%, the least rot index (0.5) and seedling vigour index (5.4). Though neem leaf extract proved to be fungitoxic against F.verticilloides, further investigation on the pathogenic mode of action of fusariotoxin on germination and growth of cereal crops on the field is necessary

In vitro culture of Telfairia occidentalis under different cytokinins and auxin combination

Telfairia occidentalis is a tropical vine and has been a good source of iron rich vegetable to man. It is normally propagated through seeds but the seeds are recalcitrant in nature. The vegetative propagation of T. occidentalis has been difficult hence there is a need to develop an in vitro method. Nodal cuttings of T. occidentalis was cultured on Murashige and Skoog (MS; 1962) basal media supplemented with IBA, IAA, NAA, BAP, and kinetin at different concentrations. Among all the growth hormones used, IBA and BAP combination gave the best result for both rooting and shooting while BAP in combination with NAA showed the highest number of nodes. The result showed that in vitro growth of T. occidentalis is hormone specific

Mycotoxins profiling of the culture material of Fusarium verticillioides (Sacc.) Nirenberg culture (CABI-IMI 392668) isolated from rice in Niger State, Nigeria...

Full Title: Mycotoxins profiling of the culture material of Fusarium verticillioides (Sacc.) Nirenberg culture (CABI-IMI 392668) isolated from rice in Niger State, Nigeria and its cytotoxic effects on human lymphocytes comparatively to those of some mycotoxin standardsAbstract: An extract of Fusarium verticillioides (Sacc.) Nirenberg culture isolated from rice in Niger State, Nigeria, previously found to be acutely toxic to mice and chicks was established to contain 8.233 ppm of total fumonisins (FBs). The present work was undertaken to evaluate the in vitro cytotoxic effect to human lymphocytes of the same 4-year old extract via flow cytometry over a 3 h period in comparison with those of aflatoxin B1 (AFB1), ochratoxin A (OTA) and fumonisin B1 (FB1) and to further elucidate the mycotoxins in extract using thin layer (TLC), column (CC) and high performance liquid chromatographic (HPLC) techniques. The efficiencies of different solvents for extraction of FBs were also determined. A dose-dependent response was obtained for all toxins tested via cytotoxicity assay. At concentrations of 25, 50 and 100 μg/ml, OTA was more toxic than AFB1 followed by the  extract which was comparatively as toxic as FB1. Cytotoxicity data also revealed that, apoptosis is the major form of cell death induced by the tested mycotoxins and extract. Fumonisins B1 (FB1), B2 (FB2) and B3 (FB3) were found in the fungal extract at concentrations of 16.302, 6.423 and 2.456 ppm, respectively. The results also demonstrated that FBs are not extractible in hexane, benzene, diethyl ether and ethyl acetate, very low amount of the toxins can be recovered using dichloromethane (5 to 7%) and acetone (<10%), while methanol, acetonitrile and their aqueous solutions (32 to 87%) were found to be the best FBs extraction solvents.Key words: Cytotoxicity, human lymphocytes, fumonisins, rice, Nigeria

The effect of processing and preservation methods on the oxalate levels of some Nigerian leafy vegetables

Titrimetric analysis was used to estimate the level of oxalate in some Nigerian leafy vegetables treated in different ways in two sets of experiments. The treatments were boiling with retention of the water used for boiling, and freezing followed by boiling without retention of the water used for boiling. Results obtained showed that the former in which five different vegetables were used led to significant increases (

Fungi and some mycotoxins contaminating rice (Oryza Sativa) in Niger State, Nigeria

Study on the fungi and some mycotoxins (Aflatoxin B1 - AFB1, ochratoxin A - OTA and zearalenone -ZEN) contaminating rice (Oryza sativa) in Niger State of Nigeria was carried out. One thousand and sixty two fungi were isolated and identified from one hundred and ninety six mouldy rice samples collected from the state. The major fungal genera contaminating rice were Aspergillus, Penicillium, Fusarium,Alternaria, Mucor, Rhizopus, Trichoderma, Curvularia,  elminthosporium and Cladosporium. The most prevalent fungal species on rice were .Penicillium spp., A. flavus, A. parasiticus, A. niger, Mucor spp.,Rhizopus spp. and Alternaria spp. The commonest fungal contaminants of the dry, harmattan; dry-hot and rainy seasons were A. niger, Penicillium spp. and A. flavus respectively. AFB1 was detected in 97 ofthe samples analyzed at concentrations between 20-1642 ug/kg. Fifty six of the one hundred and forty samples analyzed for OTA contained the toxin (24 – 1164 ug/kg). Zearalenone was found in ninety threeof the one hundred and ninety six mouldy rice samples analyzed at concentrations of between 24 and 1169 ug/kg. Twenty two samples were concurrently contaminated with the three toxins while sevenothers were found to contain both AFB1 and OTA. AFB1 and ZEN occurred together in twelve samples, and eight samples contained both OTA and ZEN

Toxicologic screening of fungi isolated from millet (pennisetum spp) during the rainy and dry harmattan seasons in Niger state, Nigeria

A survey of fungi contaminating mouldy field, stored and marketed millet samples collected during rainy and dry harmattan seasons of the year 2000 from the twenty five local government areas of NigerState, Nigeria, was conducted. Some of the fungal isolates from the two groups of samples were screened for their mycotoxin producing potentials in mice. Aflatoxin B1 content of the rainy season millet samples was determined. Aspergillus niger was the predominant fungi found in millet during the rains. Twelve out of the 49 wet season millet samples were contaminated with AFB1 at concentrations between 1370.28 and 3495.10 ug/kg. Penicillium spp. was the commonest contaminant of millet during the dry harmattan season. Thirty five of the fifty five fungal isolates screened for toxicity were found to produce toxic metabolites that were lethal to mice and were isolates of Aspergillus, Fusarium, Penicillium, Rhizopus, Mucor, Syncephalastrum, and Helminthosporium

Natural multi-occurrence of mycotoxins in rice from Niger State, Nigeria

Twenty-one rice samples from field (ten), store (six) and market (five) from the traditional rice-growing areas of Niger State, Nigeria were analysed for aflatoxins (AFs), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisin B1 (FB1) and B2 (FB2), and patulin (PAT) by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) respectively. T-2 toxin was determined using TLC only. AFs were detected in all samples, at total AF concentrations of 28–372 μg/kg. OTA was found in 66.7% of the samples, also at high concentrations (134–341 μg/kg) that have to be considered as critical levels in aspects of nephrotoxicity. ZEA (53.4%), DON (23.8), FB1 (14.3%) and FB2 (4.8%) were also found in rice, although at relatively low levels. T-2 toxin was qualitatively detected by TLC in only one sample. Co-contamination with AFs, OTA, and ZEA was very common, and up to five mycotoxins were detected in a single sample. The high AF and OTA levels as found in rice in this study are regarded as unsafe, and multi-occurrences of mycotoxins in the rice samples with possible additive or synergistic toxic effects in consumers raise concern with respect to public health

Effects of Lippia multiflora leaf extract and Aspergillus flavus on germination and vigour of Sorghum bicolor (Moench)

No Abstract. IJOTAFS Vol. 2 (2) 2008: pp. 130-13