Fungi In Maize Research Articles

Characterization and diversity of potential mycotoxin producing endophytic fungi isolated from maize husk leaves

Maize (Zea mays L.) is an important staple food due to its good nutritional profile. Unfortunately, maize can be vulnerable to contamination by fungi, which are capable of producing mycotoxins that have an impact on human and animal health, crop productivity and lead to economic losses. In addition, the ubiquitous presence of mycotoxin-producing fungi in maize poses significant challenges to food safety and economic stability. Mycotoxins are toxic secondary metabolites produced by certain fungi, which, when ingested by humans or animals through contaminated maize products can lead to a variety of health issues. There is a shift of non-pathogenic microbes to pathogenic state due to unfavourable conditions arising. The aim of this study was to characterize and identify fungi that have the potential to produce mycotoxins isolated from maize husks. The study identified Fusaria sp., Aspergillus and Penicillium sp. as target species since they are often regarded as primary mycotoxin producing fungi, which often contaminates the maize plants. Ten (n=10) healthy (disease-free) and mature maize samples were obtained, and a total of 200 maize husk segments were utilized to isolate eighty-four (n=84) endophytic fungi. Preliminary identification was conducted using macroscopic and microscopic characteristics. Molecular processes using the Internal transcribed spacer region (ITS1 and ITS4) were used for PCR amplification as a confirmatory test. A total of 13 isolates were identified by macroscopic and microscopic characterization based on morphological features and their identification was confirmed using molecular techniques. Fusaria sp. were found to be predominant (46%), followed by Aspergillus sp. (39%) and Penicillium sp. (15%). The findings suggest a community of mycotoxin producing fungi inhibited within the maize husks. Under unfavourable conditions, these fungi might be the source of contamination and produce mycotoxins. In the face of changing environmental conditions and evolving fungal threats, our research serves as a valuable resource for understanding and addressing the challenges posed by mycotoxin contamination in maize. Effective strategies and interventions are essential to mitigate the impact of these fungi on food security, human health, and the global maize industry. Key words: Endophytes; fungi; food safety; maize; maize husks; mycotoxin; mycotoxin-producing fungi

Synthesis and investigation of nano-biologic structures’ effect on soil pathogenic fungi in maize

Maize soil pathogenic fungi, Fusarium moniliforme, Macrophomina phaseolina, and Rhizoctonia zeae are important causes of annual economic losses worldwide. Since there are no maize cultivars with complete resistance to soil-borne fungal pathogens. This study aims to produce highly effective Nano-formulations of Peganum harmala and Ailanthus altissima plant extracts to control maize soil fungi. The GC-MS, DLS, Zeta, TEM, SEM, FTIR, disease symptoms, fresh and dry weights, Catalase, and Peroxidase enzymes were measured under in-vitro and in-vivo conditions. Harmine and Quercetin were the most common compounds in the extracts. The obtained results showed that the particles were spherical and encapsulated on a nanoscale. The in-vitro results showed that the best treatment for the F. moniliforme, M. phaseolina, and R. zeae fungi was P. harmala Nanoemulsion at 20 % concentration with 78.7 % inhibition. Maize seed priming with 20 % P. harmala Nanoemulsion showed the highest fresh and dry weights of 75.2 and 25.2 g, respectively, with minimal disease symptoms. The highest activity of Catalase and Peroxidase, 6.2 and 2.4 U mg protein−1 min−1, respectively.

Unlocking the growth-promoting and antagonistic power: A comprehensive whole genome study on Bacillus velezensis strains

Bacillus species are extensively documented as plant growth-promoting rhizobacteria, contributing significantly to the enhancement of soil fertility, nutrient recycling, and the control of phytopathogens. Utilizing them as biocontrol agents represents an environmentally friendly strategy, particularly within the rhizospheric community. This study presents the comprehensive genome sequences of three B. velezensis strains (LGMB12, LGMB319, and LGMB426) which were previously isolated from root samples of maize (Zea mays L.), along with a type strain FZB42. The research assesses the capability of the three strains for antagonizing fungi, specifically Fusarium graminearum, Fusarium verticillioides, Colletotrichum graminicola, and Stenocarpella sp. In paired cultures involving maize fungi, treatments containing bacteria B. velezensis exhibited statistically significant differences compared to both negative and positive treatments in terms of antagonism. Furthermore, genome mining techniques were employed to explore their inherent antagonistic potential. The assembly revealed that strains LGMB12, LGMB319, LGMB426, and FZB42 exhibit genome sizes of 4,187,541 bp, 4,244,954 bp, 3,976,537 bp, and 3,990,518 respectively. Their respective G + C content stands at 46.42 %, 46.50 %, 46.51 %, and 46.38 %. Moreover, the genomes present multiple gene clusters responsible for the synthesis of secondary metabolites and carbohydrate-active enzymes (CAZymes). These clusters highlight a diverse array of antibacterial and antifungal properties, complemented by numerous plant growth-promoting genes. These results highlight the potential of B. velezensis LGMB12, LGMB319, and LGMB426 strains as biocontrol and plant growth promotion agents, being promising candidates for further studies in agricultural production, including field trials.

Study protocol to assess aflatoxin M1 health risks versus benefits of dairy consumption in Ethiopian children: an epidemiological trial and risk-benefit analysis

IntroductionIn Sidama, Ethiopia, animal-source foods can be difficult to access. Milk has important nutrients for child growth, but carries the risk of aflatoxin M1 (AFM1) contamination. AFM1 is a metabolite...

Meta-omics revealed that nitrogen fertilization alters the endophytic fungi divergence in maize field ecosystem

Endophytic mycobiomes are an integral part of crops in agricultural systems. Fertilization is a conventional practice to improve agricultural crops and may alter the mycobiomes of soil and plant systems. In agroecosystems, Nature Based Solutions (NBS) are key strategies for agricultural suitability. Investigating mycobiomes under N flux can provide fundamental data for constructive NBS strategies. In this study, the effects of nitrogen (N) fertilizer treatments on fungal compositions of the soil-maize systems were systematically investigated in field experiments at six N rates (F0, F72, F126, F180, F234, F280 kg N/ha) in northern China. Meta-omics amplicon sequencing of the internal transcribed spacer (ITS) region was employed to study community dynamics, network correlation, metabolic functional assemblies, abundance patterns and core fungi. This study found that fungal communities were significantly higher at 72 kg N/ha compared with control and other treatments. Network topology increased in maize fungi (R2 = 0.69) but decreased in the soil (R2 = 0.51). Abundances of carbon–nitrogen metabolizing functional genes (Ure, AMT, gdhA and GDH) were significantly correlated with maize fungal communities and were assembled by stochastic processes. Additionally, the relative abundance of Ascomycota (67.26 %) was dominant in the soil, whereas Basidiomycota (61. 73 %) prevailed in maize samples at 72 kg N/ha. Moreover, Sporidiobolus, Alternaria, Fusarium, and Penicillium served as conserved core genera and were positively correlated with NH4+-N mg/kg, NO2–-N mg/kg and NO3–-N mg/kg, and pH components. Furthermore, selective genera were tested and confirmed to increase the growth rate and nitrogen utilization in maize. The study highlights the promising role of associated endophytes as Nature-Based Solution for optimizing fertilization to improve crop production in maize-agroecosystem.

ISOLATION AND IDENTIFICATION OF BROAD-SPECTRUM ANTAGONIST BACTERIA AGAINST PATHOGENIC FUNGI OF MAIZE CROP

Fungal diseases may cause significant damage to crops worldwide, generating yield losses, poor grain quality, and health risks to humans and animals. Biological control using antagonistic bacteria offers innovative solutions for sustainable management aiming at plant protection. However, beneficial plant-microorganism interactions are particular, and few antagonists with broad-spectrum activity have been reported. In this work, two bacteria isolated from sorghum seeds were identified by partial sequencing of the 16S rRNA gene and tested in vitro for their capacity to control six important pathogenic fungi of maize: Fusarium verticillioides, Macrophomina phaseolina, Stenocarpella sp., Fusarium graminearum, Colletotrichum graminicola, and Bipolaris sp. The molecular identification revealed that the bacterial isolates belong to the genera Bacillus (strain LIS05) and Paenibacillus (strain LIS04). Both bacterial isolates inhibited the growth of all six phytopathogens by at least 49%. The isolate LIS05 showed the most significant antagonistic potential against the fungal pathogens tested, at an average of 73% inhibition. The highest antagonist activity (86.1% inhibition) was observed in the confrontation test between the isolate LIS05 and C. graminicola. In addition to the mycelial growth inhibition, the isolate LIS04 blocked the production of dark pigments by Bipolaris sp. This study showed that LIS05 and LIS04 are promising alternatives for developing integrated management strategies to control fungal diseases in maize and sorghum.

Systematic analysis of the Rboh gene family in seven gramineous plants and its roles in response to arbuscular mycorrhizal fungi in maize

BackgroundPlant respiratory burst oxidase homolog (Rboh) gene family produces reactive oxygen species (ROS), and it plays key roles in plant–microbe interaction. Most Rboh gene family-related studies mainly focused on dicotyledonous plants; however, little is known about the roles of Rboh genes in gramineae.ResultsA total of 106 Rboh genes were identified in seven gramineae species, including Zea mays, Sorghum bicolor, Brachypodium distachyon, Oryza sativa, Setaria italica, Hordeum vulgare, and Triticum aestivum. The Rboh protein sequences showed high similarities, suggesting that they may have conserved functions across different species. Duplication mode analysis detected whole-genome/segmental duplication (WGD)/(SD) and dispersed in the seven species. Interestingly, two local duplication (LD, including tandem and proximal duplication) modes were found in Z. mays, S. italica and H. vulgare, while four LD were detected in T. aestivum, indicating that these genes may have similar functions. Collinearity analysis indicated that Rboh genes are at a stable evolution state in all the seven species. Besides, Rboh genes from Z. mays were closely related to those from S. bicolor, consistent with the current understanding of plant evolutionary history. Phylogenetic analysis showed that the genes in the subgroups I and II may participate in plant-AM fungus symbiosis. Cis-element analysis showed that different numbers of elements are related to fungal induction in the promoter region. Expression profiles of Rboh genes in Z. mays suggested that Rboh genes had distinct spatial expression patterns. By inoculation with AM fungi, our transcriptome analysis showed that the expression of Rboh genes varies upon AM fungal inoculation. In particularly, ZmRbohF was significantly upregulated after inoculation with AM fungi. pZmRbohF::GUS expression analyses indicated that ZmRbohF was induced by arbuscular mycorrhizal fungi in maize. By comparing WT and ZmRbohF mutant, we found ZmRbohF had limited impact on the establishment of maize-AM fungi symbiosis, but play critical roles in regulating the proper development of arbuscules.ConclusionsThis study provides a comprehensive analysis of the evolution relationship of Rboh genes in seven gramineae species. Results showed that several Rboh genes regulate maize-AM fungal symbiosis process. This study provides valuable information for further studies of Rboh genes in gramineae.

Prevalence of fumonisin-producing fungi in maize (Zea mays) obtained from markets in the southern region of Nigeria

Prevalence of fumonisin-producing fungi in maize (Zea mays) obtained from markets in the southern region of Nigeria

Exploration of novel syringic esters as antifungal agent against phytopathogenic fungi of maize: Structure-activity studies.

The production of maize is limited by major diseases such as foliar blights, stalk rot, maydis leaf blight; banded leaf and sheath blight and many more. Synthesis of ecologically sustainable and naturally derived products can help us counter these diseases. Hence, Syringaldehyde (a natural occurring isolate) should explore as a viable option as green agrochemical. We performed a structure-activity study to optimize syringaldehyde and its physicochemical properties. A series of novel syringaldehyde esters was synthesized and investigated focusing on esters' nature of lipophillicity, and membrane affinity. Tri-chloro acetylated ester of syringaldehyde was emerged as broad-spectrum fungicide.

Prevalence and Management of Phytopathogenic Seed-Borne Fungi of Maize

Seed-borne fungi are solemn and deleterious pathogens capable of causing significant losses of quantity and quality losses in maize seeds and seedlings. They infect the crop at all points of the production chain from farms to stores. A yield loss of up to 50% can be encountered. Currently, chemical control of the disease is being implemented, though it is accompanied by several negative effects. This study aimed at identifying seed-borne fungi of maize and effective management options. A deep-freezing blotter method and morphological identification of the fungal species were implemented. The seed-borne fungi detected were Fusarium verticillioides, Aspergillus flavus, Aspergillus niger, Penicillium spp., Rhizopus spp., and Curvularia spp. However, in farmer-saved seeds, fungal incidences were significantly higher (p < 0.01) than in certified seeds. To identify more effective management options, the efficacy of water and ethanol-extracted bio-fungicides from three plant species, namely, neem (Azadirachta indica), ginger (Zingiber officinale), and coffee (Coffea arabica) were evaluated. From in vitro assays, ethanol-extracted bio-fungicides have a 100% inhibitory effect on fungal growth, whilst the inhibitory effects of water-extracted bio-fungicides are 55.88% (Azadirachta indica) and 46.31% (Zingiber officinale), followed by 5.15% (Coffea arabica). For the case of an in vivo assay, maize seeds treated with water-extracted bio-fungicides have higher seed germination and seedling vigor percentages. For germination, seeds treated with water-extracted bio-fungicides have higher percentages (neem and ginger (90%) followed by coffee (72.5%)) than ethanol-extracted bio-fungicides (neem (0%), ginger (2.5%), and coffee (0%)). A similar observation is made for seedling weight. Therefore, the tested water-extracted bio-fungicides can be used in treating seeds before sowing them. Further studies on effective methods of extracting bioactive compounds, and improving their shelf life, are recommended.

Distribution and Biodiversity of Seed-Borne Pathogenic and Toxigenic Fungi of Maize in Egypt and Their Correlations with Weather Variables.

Studies of the biodiversity of plant pathogenic and toxigenic fungi are attracting great attention to improve the predictability of their epidemics and the development of their control programs. Two hundred maize grain samples were gathered from 25 maize-growing governorates in Egypt and 189 samples were processed for the isolation and identification of seed-borne fungal microbiome. Twenty-six fungal genera comprising 42 species were identified according to their morphological characteristics and ITS DNA sequence analysis. Occurrence and biodiversity indicators of these fungal species were calculated. Ustilago maydis, Alternaria alternata, Aspergillus flavus, A. niger, Penicillium spp., Cladosporium spp. and Fusarium verticillioides were the highly frequent (>90% for each), recording the highest relative abundance (˃50%). Al-Menia governorate showed the highest species diversity and richness, followed by Sohag, Al-Nobaria and New Valley governorates. Correlations of 18 fungal species with temperature, relative humidity, precipitation, wind speed, and solar radiation were analyzed using canonical correspondence analysis. Results showed that relative humidity, temperature, and wind speed, respectively, were the most impactful weather variables. However, the occurrence and distribution of these fungi were not clearly grouped into the distinctive climatic regions in which maize crops are grown. Monitoring the occurrence and distribution of the fungal pathogens of maize grains in Egypt will play an important role in predicting their outbreaks and developing appropriate future management strategies. The findings in this study may be useful to other maize-growing countries that have similar climatic conditions.

Thymol and its Derivatives for Management of Phytopathogenic fungi of Maize

Background: Thymol is a bioactive compound having many pharmacological activities. Objective: The present study was carried out to evaluate the fungi toxic effects of thymol and derivatives against phytopathogenic fungi of maize. Method: Thymol was derivatized to get formylated thymol, Mannich bases, and imine derivatives. All the synthesized thymol derivatives were characterized by their physical and spectral properties. Synthesized thymol derivatives were screened for their in vitro antifungal effects using poisoned food technique against three maize pathogenic fungi, namely Fusarium moniliforme, Rhizoctonia solani and Dreschlera maydis. Results: Thymol and formylated thymol showed promising results for control of D. maydis with ED50 values less than standard carbendazim and comparable to standard mancozeb. These two compounds were further evaluated for control of D. maydis causative maydis leaf blight disease on maize plants grown in the field during the Kharif season (June to October) 2018. Conclusion: Thymol exhibited significant control of maydis leaf blight disease of maize and emerged as a potential alternative to synthetic fungicides used in cereal crops.

Control of Maize Sheath Blight and Elicit Induced Systemic Resistance Using Paenibacillus polymyxa Strain SF05.

Maize (Zea mays L.) is an important crop in the world and maize sheath blight damages the yield and quality greatly. In this study, an antagonist strain, which exhibited antagonism against pathogenic fungi of maize and controlled maize banded leaf sheath blight in the field, was effectively isolated and named Paenibacillus polymyxa strain SF05. High cellulase and chitinase activity of the strain were detected in this study, which might contribute to degrading the cell wall of fungi. Furthermore, different resistant genes such as ZmPR1a, OPR1 and OPR7 were elicited differently by the strain in the leaves and stems of maize. In order to explain the biocontrol mechanism of P. polymyxa strain SF05, the genome was sequenced and then the genes involving the biocontrol mechanism including biofilm formation pathways genes, cell wall degradation enzymes, secondary metabolite biosynthesis gene clusters and volatile organic compounds biosynthesis genes were predicted. The study revealed the biocontrol mechanism of P. polymyxa strain SF05 preliminary and laid a foundation for further research of biocontrol mechanism of P. polymyxa.

Detection of aflatoxin-producing fungi in maize

Maize samples (n = 110) were collected from five different areas of Dinajpur district from July 2018 to July 2019 for the detection of aflatoxin-producing fungi and aflatoxin. Aflatoxin-producing fungi were detected using culture and morphological features, and aflatoxin was detected using Agra Strip total aflatoxin test (20 ppb cut-off). Aspergillus spp. were detected in 56% of fresh and 23.2% of stored maize samples. Aflatoxin-producing fungi were detected in 28% of fresh samples and aflatoxin was detected in 10% of stored samples. Out of 110 maize samples, Aspergillus spp was identified in 38.2%, and aflatoxinproducing fungus was found in 18.2%. The presence of aflatoxin-producing fungus in stored maize increased significantly (P<0.01) with storage. In 20 samples aflatoxin level was more than 20 ppb. The Bangladesh Veterinarian (2020) 37(1 - 2): 27-35

Effect of Selected Fungicides in the Control of Aflatoxin-producing Fungi in Pre-harvest Maize (Zea mays L) in Anambra State

Contamination of maize by toxigenic fungi is the process that occur yet in the field. Aflatoxin contamination in several foodstuffs has been a recurrent problem. This study is aimed to evaluate the effect of selected fungicides in the control of aflatoxin-producing fungi affecting growth in pre-harvest maize (Zea mays L). Maize seeds treated with organic and synthetic fungicides were sown immediately after land preparation comprising of 13 plots. Five plants each were randomly selected from 13 plots for collecting data for 12 weeks at 2 week interval. Effect of organic and synthetic fungicide in the control of aflatoxin production on the growth parameters of maize showed that maize treated with Azadirachta indica recorded significant growth in the leaf area for all treatments for weeks 8, 10 and 12 while at week 6, maize treated with Cymbopogon citratus showed significant growth in the leaf area at 0.05% for TLg25%, TLg75% and TLg100%. Maize treated with synthetic fungicide (mancozeeb) showed significant growth in the leaf area for weeks 8, 10, 12 in all treatments. Maize treated with Azadirachta indica recorded a significant difference in the plant height for week 4, 10 and 12 in all treatments. For maize treated with Cympobogon citratus, weeks 2 and 8 recorded no significant difference in the plant height but showed a significant growth in the plant height at weeks 4 and 12 (for all treatments) while weeks 6 and 10 recorded significant growth in the plant height for some of the treatments. Maize treated with synthetic fungicide showed significant growth in the plant height for weeks 4, 10 and 12. Fungal isolates identified in this study were: Aspergillus spp. Fusarium spp. and Penicillium spp., with Aspergillus spp. having the highest frequency of occurrence of 4 in treatments TAi100%, TLg75%. The result showed that both organic and synthetic fungicide were effective in the control of aflatoxin-producing fungi on the maize yield but was more effective with the organic fungicide. The use of Azadirachta indica and Cymbopogon citratus is recommended as a means of biofungicides to control aflatoxin-producing fungi in maize.

Agronomic practices and mycorrhizal development and function in maize: Root fungal interactions may affect early nutrition and yield

Efficient management of soil biota and fertilization to reduce environmental impacts of agriculture requires understanding of functional soil biota-crop relationships and how they interact with management practices. An experiment was conducted to examine functional interactions between native arbuscular mycorrhizal (AM) fungi and maize nutrition, development and yield, for understanding and capturing most mycorrhizal benefits in the field. Soil tillage, fertilization and fungicide treatments were used to manipulate early AM development and functioning and test the hypothesis that the rapid root colonization and preservation of AM networks in soil would increase early P uptake and biomass, and later increase the yield and nutritional quality of the grain in comparison with treatments reducing early mycorrhizal development and function. The treatments succeeded in modulating mycorrhizal development and achieved up to 95% reductions in early root colonization. Tillage generally had few significant effects on most variables. Furthermore, the fungicide improved early nutrition and yield, and fertilization increased the nutrition, biomass, yield and grain quality. Early functional AM-maize relationships were positive at the third leaf (V3) stage but became negative at the sixth (V6) and tenth (V10) leaf stages, when root colonization by AM fungi and by other fungi increased, especially in treatments without fungicide. The abundance of AM fungi and other fungi in roots was negatively related to early shoot N and P, and some treatments did not reach the critical concentrations of N or P at V6. The shoot N and P reductions did not significantly affect the biomass during vegetative growth, but the yield was reduced by 10% in treatments without fungicide. Fertilization, which increased the yield by 30%, compensated for yield depression in treatments without fungicide. Close monitoring of early events in the development and functioning of AM-maize symbiosis suggested that early reductions in maize shoot N and P, and later the yield, were related to the combined effects of root colonization by mycorrhizal and non-mycorrhizal fungi. These results provide new evidence for the involvement of other root fungi in maize's early nutrition and yield depressions already reported in low fertility soils, which had been overlooked and attributed solely to AM fungi.

A Case Study in Saudi Arabia: Biodiversity of Maize Seed-Borne Pathogenic Fungi in Relation to Biochemical, Physiological, and Molecular Characteristics.

Microbiodiversity is usually correlated with environmental conditions. This investigation is a case study to cover the lack of knowledge on the correlation of biochemical, physiological, and molecular attributes with the distribution of seed-borne pathogenic fungi of maize under the environmental conditions of the Kingdom of Saudi Arabia to help forecast any destructive epidemics. Forty-one fungal species belonging to 24 genera were detected using standard moist blotter (SMB), deep freezing blotter (DFB), and agar plate (AP) techniques. SMB was superior in detecting the maximum numbers (36 species) of seed-borne mycoflora. The pathogenicity assay revealed that, among 18 seed-borne fungal pathogens used, 12 isolates caused high percentages of rotted seeds and seedling mortality symptoms, which were identified molecularly using an internal transcribed spacer sequence. Two Curvularia spp. and Sarocladium zeae were reported for the first time in KSA. The strains showed various enzymatic activities and amino acid profiles under different environmental setups. Temperature and humidity were the environmental variables influencing the fungal pathogenicity. The highest pathogenicity was correlated with the presence and concentration of threonine, alanine, glutamic, aspartic acids, and protein. The study concluded with the discovery of four new phytopathogens in KSA and, further, evidenced a marked correlation among the investigated variables. Nevertheless, more studies are encouraged to include additional physiological properties of the phytopathogens, such as toxigenic activity, as well as extend the fungal biodiversity study to other plants.

Poisson distribution-based conventional PCR protocol for quantification of pathogenic fungi in maize

Currents study aims to optimize and apply a conventional PCR protocol based on digital assay principle for quantification of pathogenic fungi in maize. Conventional PCR based on Poisson distribution is an effective and technically simple method for quantitative analysis of plant pathogens. It doesn’t require specific reagents or sophisticated laboratory equipment. Unlike qPCR, no standard curve is needed for quantifying the number of copies per sample. It permitted to quantify several toxigenic and non-toxigenic fungal pathogens in maize plants and reveal genome impact on the quantity of fungal DNA in host organism. Overall, fungal quantity was lowest in ‘MK01’ and ‘KU123’ and highest in ‘CP137’. High quantity of fungal DNA was also computed for ‘CP148’. For ‘B73’ the fungal DNA quantity was in between the same values for ‘KU123’ and ‘CP148’.

Antifungal Potential of Dill (Anethum graveolens L.) Seed Essential Oil, its Extracts and Components Against Phytopathogenic Maize Fungi

Dill (Anethum graveolens L.) is an aromatic herb that is mainly used as a flavoring agent in the food industry. It has been also used to treat various ailments. Many reports are available in the literature regarding its biological activities. So, the present study reports the fungitoxic impact of dill (Anethum graveolens L.) seed extracts, essential oil, isolated and derivatized compounds using the poisoned food technique against phytopathogenic maize fungi (Fusarium verticillioides and Drechslera maydis). GC/MS analysis of hydro distilled essential oil (yield 1.5%) revealed carvone (42.2%) and limonene (30.0%) to be the major compounds that were further isolated using column chromatography and were chemically modified. Dill seed extracts were prepared by different extraction methods (maceration, sonication, and soxhlet) using methanol and hexane solvents and maximum yield was observed for soxhlet extraction (5.7%). The antifungal activity of all the components (essential oil, extracts, isolated compounds and derivatives) was evaluated at different concentrations (125-1000 μg/mL) using Carbendazim 50 WP and Mancozeb 75 WP as the positive control. Overall, the isolated compounds and their derivatives were more effective in comparison to the extracts and essential oil. Further, the activity was increased with increasing the concentration as well as the polarity of the molecule.

Screening of aflatoxin-producing fungi in maize and groundnuts from three regions in Tanzania

This study screened aflatoxin-producing fungi in maize and groundnuts from Dodoma, Singida and Iringa regions in Tanzania, and assessed the level of peoples’ awareness on aflatoxins health effects. One hundred and twenty samples (20 each crop) were collected and inoculated on Sabouraud dextrose agar and one hundred and eleven samples were observed to have fungal growths that were identified to belong to four genera, namely Aspergillus, Rhizopus, Mucor and Dermatophyte with occurrence frequencies of 75, 2.5, 5 and 10%, respectively. Among the four screened genera of fungi, Aspergillus was observed to be the major aflatoxin-producing fungi. Five species of genus Aspergillus, namely A. flavus, A. parasiticus, A. niger, A. fumigatus, and A. terreus were isolated with frequencies of 39.1, 10, 7.5, 15.8 and 2.5%, respectively. Macromorphology and micromorphology of isolated Aspergillus spp were also observed using a light microscope. Furthermore, it was noted that the prevalence of fungi and aflatoxins contamination is more in groundnuts than in maize. In terms of awareness in individuals concerning aflatoxins, only 34% respondents in Dodoma, 29.9% in Singida and 24% in Iringa were aware of aflatoxins. Therefore, the creation of awareness and sensitization on aflatoxins health effects to the people is an important part of intervention ways to forestall and control aflatoxins in Tanzania.
 Keywords: Aflatoxins, Maize, Groundnuts, Aspergillus spp, A. flavus, A. parasiticus, A. niger, A. fumigatus and A. terreus