Browsing by Author "Olahan, G.S."

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    Antifungal Efficacy of Leaf Extracts of Neem, Bitterleaf and Their Mixture Against Ustilago scitamineum
    (Faculty of Biosciences, Nnamdi Azikiwe University, Awka., 2022-03-30) Olahan, G.S.; Fatoba, P.O.; Balogun, O.S.
    This study was aimed at evaluating the antifungal activity of leaf extracts of neem, bitterleaf and their mixture against Ustilago scitamineum (Syd.), the pathogen of sugarcane smut disease. A suspension of mancozeb, carbendazim+maneb, matalaxy l+ carboxin + flurathiocarb, pyroquilon, benomyl, chlothalonil and flutriafol are effective as a dip in controlling the disease. However, the listed synthetic fungicides led to emergence of resistant strains of the pathogen and also cause environmental pollution. Hot water treatment of the cane setts at 52º C for 30 minutes before planting is also effective, but this can cause serious injuries on sugarcane farmers if not carefully practiced. Pour Plate method was used to determine antifungal effect of 10, 20 and 30 g/ 100 ml concentrations of aqueous and ethanolic leaf extracts of neem, bitterleaf and their mixture on radial growth of U. scitamineum for 6 days. The tested leaf extracts inhibited mycelial growth of U. scitamineum in vitro, with the ethanolic leaf extracts being more potent at some of the concentrations tested in this study. In conclusion, gradient of antifungal efficacy of the tested leaf extracts against U. scitamineum was: mixed leaf extracts > neem leaf extracts >bitterleaf leaf extracts at all the concentrations used.
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    Assay of Bioactive Compounds in Stored kolanuts
    (Faculty of Biosciences, Nnamdi Azikiwe University, Awka., 2023-01-28) Olahan, G.S.; Ajadi, I; Issa, B.T.
    Kolanuts are widely consumed by humans. The medicinal and therapeutic potentials of plants are credited to their bioactive compounds. This study was aimed at investigating the bioactive compounds in kolanuts from Ifelodun and Odo-Otin Local Government Areas of Osun State, popular kolanut producing LGAs in Nigeria. The bioactive compounds were identified using Gas Chromatography-Mass Spectrometry (CG-MS) to analyse crude extracts of the kolanuts using acetone: methanol (1: 1 v/v) as the extractant. Twenty five (25) bioactive compounds were identified, with 9-Octadecenoic acid, methyl ester (32.91%) being the predominant compound. Six (6) of the bioactive compounds were common in all the kolanuts (caffeine, hexadecanoic acid, methyl ester, n-hexadecanoic acid, 9, 12-Octadecadienoic acid, methyl ester (z, z), methyl stearate, and phthalic acid, di (oct-3-yl) ester). Some of the bioactive compounds were identified only in the kolanuts from Ifelodun LGA eg nonanoic acid, methyl-2-octylcyclopropene-1-heptanoate, 9-octadecanoic acid (z), 9-octadecanoic acid. Also, 11-octadecanoic acid, methyl ester (z), 2-chloroethyl linoleate, bicyclo (4.1. 0) heptane, etc were present only in the kolants from Odo-Otin LGA Out of the 25 bioactive compounds identified, only 12 have been reported to be present in kolanuts some of eg caffeine, n-Hexadecanoic acid, etc, while the remaining 13 have been reported in other plants other than kolanuts.
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    Comparative biodiversity assessment of weed species in monocropping plantations of University of Ilorin, Nigeria.
    (Institute for Enviroment and Sanitation Studies, University of Ghana, Legon, 2020) Olayinka, U.B.; Adeyemi, S.B.; Abdulkareem, K.A.; Olahan, G.S.; Lateef, A.A.; Garuba, T.; AbdulRahaman, A.A.
    The present study investigates the weed species diversity in four plantations of university of Ilorin, Ilorin, Nigeria using quadrat method. The survey revealed two major life cycles (annual and perennial) and recorded a total of 88 weed species belonging to 32 families. Four species (Azadirachta indica, Daniellia oliveri, Desmodium tortuosum, and Tridax procumbens) were common in all the surveyed plantations while the family Fabaceae was the most dominant. The abundant weed species analysis showed a high importance value index and were more adapted to the plantations. Diversity analysis revealed high species richness in the sugarcane plantation. The non-canopy nature of the plantation, soil structure as well as ability to coexist with many other species may underscore the reasons for this pattern of diversity. The evenness and similarity indices between and across the plantations were generally low, thus, indicating varying diversity. As a result of the recorded variation in weed composition between and across the plantations, the study has provided an insight on the pattern of weed diversity in the studied plantations. The study recommended that the most abundant weed species populations be checked for the plantations to thrive. Finally, there is an urgent need to conserve weed species that are not only rare in abundance but also showed great social and economic values.
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    Effects of fungal filtrates on seed germination and leaf anatomy of maize seedlings (Zea mays L., Poaceae)
    (JASEM, University of Port Harcourt., 2014-12) Garuba T.; AbdulRahaman, A.A.; Olahan, G.S.; Abdulkareem, K.A.; Amadi, J.E.
    This study was carried out to investigate the effects of 7-day-old fungal filtrates of Aspergillus niger and Penicillium chrysogenum isolated from maize seeds on percentage germination, morphological and anatomical structures of maize seedlings. The seeds were soaked in culture filtrate of each fungus for 12hrs before planting. Blotter method was used to observe seed germination. Results showed that the percentage germination of the seeds treated with culture filtrates of A. niger and P. chrysogenum (65.33% and 79.67% respectively) was lower than the control (100%) and significantly different from each other at significant level of P ≥0.05. The leaf area showed significant difference between the experimental and control plants but there was no significant difference in the leaf number. The tetracytic stomatal complex type and wavy anticlinal walls remained constant in all the treatments and control. The stomatal index of seed treated with A. niger on abaxial leaf surface (43.61%) showed significant difference with adaxial leaf surface (31.97%). The treatments had no significant difference on stomatal density at abaxial surfaces. Reduction in stomatal size and density suggests physiological implication.
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    Fungicidal effect of pawpaw (Carica papaya L.) leaf extracts on Fusarium verticilliodes
    (Klobex Academic Publishers, 2006-03-31) Olahan, G.S.; Amadi, J.E.
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    Identification of fungi associated with rotten sweet orange fruits (Citrus sinensis L.) in University of Ilorin Botanical Garden
    (Faculty of Science, Federal University, Birnin Kebbi, 2023) Olahan, G.S.; Ajadi, I.; Issa, B.T.
    The presence of fungi in oranges poses a significant risk to public health, impacting global economies and the well-being of both humans and animals. To effectively address this problem, it is important to identify the specific types of fungi to address this concern effectively. This study was aimed at isolating and characterizing fungal species associated with rotten sweet oranges (Citrus sinensis L.) in the University of Ilorin using phenotypic characterization and molecular tools. A total of five orange fruits were collected from different trees at the Unilorin botanical garden and immediately transported to the Biology laboratory, University of Ilorin. The rotten part of the fruits was cut out, surface-sterilized, and then inoculated onto potato dextrose agar. Aspergillus flavus, Aspergillus niger and Rhizopus arrhizus were the fungal isolated and identified. The identification of these pathogens is crucial for implementing effective post-harvest management measures. This will aid in eliminating the pathogens from sweet orange fruits during post-harvest handling, reduces spoilage and extending their shelf life. Keywords: Citrus sinensis, Fungal analysis, Molecular analysis, Potato dextrose agar, University of Ilorin.
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    In vitro antifungal efficacy of aqueous leaf extracts of neem (Azadirachta indica A. Juss.) against Lasiodiplodia theobromae, the cause of kola nuts rot in West Africa
    (Department Pathology, Faculty of Agricultural Sciences, University of Punjab, Pakistan., 2024) Olahan, G.S.; Ajadi, I
    In vitro efficacy of eco-friendly aqueous neem (Azadirachta indica A. Juss.) leaf extract was explored against the fungal pathogen Lasidioplodia theobromae (Pat.) Griffon & Maubl., the cause of storage rot of kolanuts (Cola nitida Schott & Endl.), in West Africa. Aqueous neem leaf extracts at concentrations of 10%, 30% and 50% (w/v) were used to amend freshly prepared potato dextrose agar culture medium on which discs of L. theobromae were inoculated followed by incubation at room temperature for 72 hours. The findings demonstrated significant inhibition of fungal growth, with the highest inhibition observed at 50% (w/v) concentration of the extract. This suggests that aqueous neem leaf extract possesses fungicidal properties againstL. theobromae, offering a natural alternative for controlling this pathogen and reducing pesticide residues instored kola nuts, as well as its effects on consumers and the environment as a whole.
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    Incidence of smut and red rot diseases of sugarcane in southern part of Niger State, North central Nigeria
    (Faculty of Science, Kaduna State University., 2021-01-22) Olahan, G.S.; Fatoba, P.O.; Balogun, O.S.
    Sugarcane production is threatened globally by smut and red rot diseases, which farmers in the study area take for granted because they see the diseases as natural calamities associated with large-scale cultivation of sugarcane. Incidence of smut and red rot diseases of sugar-cane in the study area was assessed between October 2016 and June, 2017. Thirty-two sugarcanes (800 per farm) were assessed on forty farms randomly selected from 16 towns/villages in Southern part of Niger State. Each of the sugarcanes aged between 6 and 10 months were observed visually for symptoms of the diseases. Number of infected sugarcanes was used to determine the percentage incidence of the diseases on each farm. Percentage incidence of smut ranged from 25.0 to 35.0 (Bida LGA), 20.0 to 22.5 (Gbako LGA) and 20.0 to 30.4 (Lavun LGA), while percentage incidence of red rot ranged from 5 to 6.5 (Bida LGA), 6.1 to 12.0 (Gbako LGA) and 5.4 to 9.3 (Lavun LGA). Significant pairwise differences at p≤0.05 existed in the means of percentage incidence of smut in Bida and Gbako as well as Bida and Lavun LGAs. Significant pairwise differences at p≤0.05 also existed in the means of percentage incidence of red rot in Bida and Gbako as well as Gbako and Lavun LGAs in this study. The study concluded that smut is of higher incidence in the study area. It is recommended that the local farmers be sensitized to adopt effective control measures for these diseases.
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    Isolation and identification of fungi associated with the rhizosphere of some economic trees
    (Valahia University Press for Faculty of Engineering and Biotechnology, Valahia University, Targoviste, Romania., 2017-12-10) Olahan, G.S.; Balogun, G.Y.; Oladokun, E.D.; Musa, K.D.; Ajayi, O.A.
    Fungi associated with the rhizospheres of some economic trees namely date palm (Phoenix dactylifera), pawpaw (Carica papaya), Sheabutter (Vitellaria paradoxa) and oil palm (Elaeis guinensis) trees were isolated and identified in this study in order to know their roles, whether pathogenic or saprophytic. The rhizospheres were collected at 5, 10, 15 and 30cm distances away from the trunk of the plants respectively for fungal isolation and identification using standard methods. Aspergillus niger, A. terreus, A. candidus, A. fumigatus, Fusarium proliferum, Pyrenochaeta romeroi and Alternaria alternata were isolated from the rhizosphere of date palm; Aspergillus niger, Candida albicans and Botrytis cinerea were isolated from the rhizosphere of pawpaw; Aspergillus niger, A. glaucus, A. cremonium killense and Cunninghamella bertholletiae were isolated from rhizosphere of shea butter while Aspergillus niger …
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    Molecular Characterisation of Some Accessions of Corchorus olitorius l.
    (Faculty of Science, Federal University Birnin Kebbi, 2019-12) Abdulkareem, K.A; Sidiq, K.A; Olayinka, B.U.; Lateef, A.A.; Garuba, T.; Olahan, G.S.; Adeyemi, S.B.; Sagaya, A.; Tiamiyu, B.B.; Abdulrahman, A.A.
    Nigeria has several native leafy vegetables that have been neglected. Corchorus olitorius belongs to this group. Genetic diversity was studied in five accessions of the plant using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS - PAGE). The aim was to determine the relationship (differences and similarities) among them. Sixteen polypeptide bands were obtained ranging from 12.29 KDa to 170 KDa indicating variations in the banding patterns of the accessions. The unweighted pair group method with arithmetic algorithm (UPGMA) dendrogram grouped the five accessions into three clusters with four groups showing 60% of the accessions in one group. The greatest similarity (96%) observed was between NGB00196 and NGB00194 while the lowest similarities (32%) NGB00191 and (40%) NGB00187. Adopting this technology can be useful in plant variety identification and registration of new plant varieties. NGB00191 was observed to be distantly related to the other accessions hence could be combined in a breeding programme.
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    Molecular characterization of potential crop pathogens associated with weeds as endophytes in Unilorin plantations, Nigeria.
    (College of Science for Women, University of Baghdad, Jadriah, Baghdad, Iraq., 2022-05-20) Lateef, A.A.; Garuba, T.; Abdulkareem, K.A.; Olayinka, B.U.; Olahan, G.S.; Adeyemi, S.B.; AbdulRahaman, A.A.
    Crop diseases are usually caused by inoculum of pathogens which might exist on alternate hosts or weeds as endophytes. These endophytes, cum pathogens, usually confer some beneficial attributes to these weeds or alternate hosts from protection against herbivores, disease resistance, stress tolerance to secondary metabolites production. This study was therefore carried out to isolate potential crop pathogens which exist as endophytes on weed species in the University of Ilorin plantations. Green asymptomaticleaves were collected from 10 weed species across the plantations, and processed for their endophytic fungi isolation. Isolates were purified into pure cultures and used for molecular identification using the internal transcribed spacer (ITS) region of the ribosomal DNA. Phylogenetic analysis of the fungal sequences using MEGA software revealed 9 fungal genera belonging to 13 species, with species in the genera Curvularia, Epicoccumand Daldiniaoccurring in more than one weed species, while other genera such as Alternaria, Fusarium, Chaetomium, Macrophomina, Arthriniumand Phomopsisoccurred in just one weed species each. Daldinia eschscholtziiwas isolated in this study as an endophyte from Loudetia arundinaceafor the first time. This plant is very abundant in Nigeria and Africa where it is used majorly for thatching and feeding livestocks. This also represents the first endophytic fungi from the genus Loudetia. Potential relationship between the occurrences of these fungi as endophytes and as pathogens are discussed. These discoveries represent the first large-scale molecular identification and several first reports of endophytes from these weed species. These results also represent the first records of some of these fungi in Nigeria.
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    Mycoflora associated with groundnut seeds collected from the three senatorial districts of kwara state, Nigeria.
    (faculty of science, federal university of kashere, Nigeria, 2023-12-31) Ajadi.I; Olahan, G.S.
    Groundnut seeds are of numerous benefits to mankind which can be reduced through contamination by fungal species, depending on the fungal species and their degree of contamination of the seeds. Occurrence of fungal species on groundnut seeds is of great public health concern. Therefore, it is essential to examine the different fungal species present. This study employed both the phenotypic and molecular methods to isolate and characterize the fungal species attributed to groundnut seeds. The Zymo Research Group's recommended protocols were followed in order to extract the genomic DNA of each of the fungal species recovered. The PCR amplification and sequencing of the ITS region from the total genomic DNA of fungal isolates were conducted to molecularly identify them, using the NCBI database for comparison. The commonest mycoflora isolated from the stored groundnut seeds were Aspergillus flavus, A. niger, Alternaria alternate, Fusarium graminearum, Macrophomina phaseolina, Penicillium digitatum and Rhizopus stolonifer. The total incidence of each of them ranged from 8-32%. Among the three surveyed districts, Kwara Central exhibited the highest incidence of major mycoflora at 40%, while Kwara North had the lowest at 27%. Aspergillus niger demonstrated the highest incidence among the fungal species found in groundnut seeds collected from all districts. Failure to adequately dry these seeds before storage could elevate the risk of mycotoxin contamination. Implementing management approaches targeting different fungi is essential to preserve nutritional value of groundnut seeds during storage.