Department of Botany

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    Phenotypic Characterization Of Cowpea.
    (University Of Ghana, 2021-12) Arthur, K.S.
    Cowpea is indigenous to the African continent and is usually grown for its leaves and grain in different countries of the world. The objective of this study was to evaluate cowpea accessions using morphological descriptors and phytochemical analysis to identify cowpea accessions with a more specific traits that could be used by breeders. Phenotypic characterization of twenty-seven (27) cowpea accessions which consist of twenty-four (24) from the Department of Plant and Environmental Biology as test material and three (3) others, namely ‘Asontem’, ‘Wang Kae’ and ‘Kirkhouse’ which were used as checks, was undertaken. The cowpea population was evaluated based on agro-morphological traits (quantitative and qualitative) and phytochemical traits. STATA version 15.0 was used to carry out descriptive, multivariate analyses whiles ‘R’ software was used for genetic component analysis to determine the extent of variation. Phytochemical analysis was carried out to study the polyphenolic and amino acid contents of the cowpea seeds using standard methods and protocols. Polyphenolic compounds were determined using a spectrometer and amino acid contents were determined with assistance from Ghana Standard Authority. In the morphological qualitative traits studied, erect cowpea plants showed the highest distribution for growth habit with frequencies of 91% in the test material and 84.17% in the entire population. The pale tan pod colour recorded the highest frequency of 62.58% in the entire population, similarly, the pale tan with frequencies 65.48% and 62.58% were the highest frequency in both control and test material respectively. The white seed coat colour had the highest frequency of 66.11%in the entire population as well. The chi-square test of association between qualitative traits showed 86 significant associations in the test materials, with growth habit having the highest signicant associations with leaf size (χ² = 220.84, P = 0.000), whereas the control showed 78 significant associations. The overall population exhibited 86 significant associations, with growth habit having the highest positive significant association with terminal leaflet shape (χ² = 243.87, P = 0.000). The phenolic compound had higher mean concentration in the controls than the test material, however higher mean concentration of amino acid was obatined in the test materials than in the control. A total of 145, 113 and 123 significant pairwise correlations were observed in the control, test materials, and entire population respectively for all quantitative traits. In the test material vanillic acid was highly correlated with gallic acid (r = 1.00) and p-coumaric acid (r = 1.00). Principal component analysis showed that, the first seven principal components in the morphological traits accounted for a total variability of 84.00% in the control, while nine principal components explained 81.00% of the total variation in the test material. On the other hand the first five principal components in the phytochemical traits accounted for 100%, 100% and 83% of the total variation in the control, test materials and entire population respectively. The biplot showed that the relationships among accessions and morphological, phytochemical and all traits explained 33% and 51% of the total variance respectively. The cluster analysis for the morphological traits revealed five distinct clusters. Genotypes named Asontem, T3, T5, T22 were grouped in a single cluster and were characterized by least days to germination (3.58), highest mean number of branches (4.93), least mean number of leaves (41.26), highest mean number of nodes (9.83), least mean leaflet width (3.69), the highest mean days to first flowering, least mean number of pods per peduncle (2.81), least average pod width (0.80), highest mean number of pods per plant (49.50), the highest average number of seed per pod (15.97), highest mean days to first matured pod (42.01), highest mean number of seeds per plants (795.75) compared to other clusters. These genotypes could be used as parents in genetic improvement programs aiming to increase yield. Biometrical analysis revealed that the phenotypic variance (σ2 p) was higher than the genotypic variance (σ2 g) regarding all morphological traits evaluated. The number of seeds per plant reported the highest genotypic (80841.20) and phenotypic (107162.90) variance while the lowest genotypic (0.09) and phenotypic (0.69) value was recorded by the days to germination and average seed thickness respectively. Low (≤20%) heritability broad sense values were observed in all the morphological traits and ranged from 0.33% for days to germination to 0.99% for seed weight.
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    Systematics Of The Genus Eulophia R. Br. (Orchidaceae) In Ghana
    (University of Ghana, 2023-01) Darko, W.B.
    The family Orchidaceae includes 850 genera and 24, 000 species, and it is arranged into 70 subtribes, 22 tribes, and five subfamilies on the basis of anther number and position. Many orchids are utilized in the traditional system of medication as medicines for several illnesses. There is no complete taxonomic revision of the genus Eulophia in Africa. A previous study based on morphological, ecological, and biogeographic characters of Eulophia cristata in Ghana has been reported by Lock and Profita (1975). However, the extent of morphological variations in species of the genus in Ghana has not been analyzed. The overall goal of this study is to undertake a systematic study of the genus Eulophia in Ghana for their sustainable utilization and conservation. 50 herbarium specimens of the genus Eulophia (35 specimens at GC, 10 specimens at CCG, and 5 specimens at KUU) were examined for morphological characters. Information from herbarium labels of the specimens examined were retrieved to understand aspects of the ecology such as phenology, habitat types and pollinator-flower relationship for the species of the genus Eulophia. Taxonomic studies focused on development of an authoritative checklist and construction of dichotomous keys for identification of species of the genus. Morphological studies on the species of Eulophia from Ghana suggested eight species but records from the herbaria in Ghana provided nine species. The members of the Eulophia range from small to large herbs, lacking woody stems; plant height ranges from 560–2000mm, 2– 16mm in width; has leaves that are often alternately arranged. Leaves are plicate, erect, often linear to lanceolate. Flowers are mostly in the shades of yellow and red, except shades of green in E. euglossa and E. flavopurpurea. Generally, the species of Eulophia have a cosmopolitan distribution across the country from the herbarium records.
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    Evaluation Of Yield And Sub-Yield Components Of Cowpea (Vigna Unguiculata (L) Walp) Accessions
    (University Of Ghana, 2021-12) Mensah, K.H.
    One hundred and eight cowpea accessions were evaluated for yield and sub-yield components at the Department of Plant and Environmental Biology. They consisted of 60 F2 segregating, 44 accessions as test materials and 4 controls. The controls were Asontem Wang Kae, Padituya and Kirkhouse from CSIR-SARI. Data collected comprised of morphological and phytochemical traits. Descriptive, multivariate and genetic component analyses were carried out to evaluate the extent of variation. Rank summation index and contrast analysis were performed to select the best performing accessions. For the morphological traits studied, semierect growth habit with frequencies of 64.78%, 43.75% and 51.45% which occurred in the test materials, controls and the entire population. The majority of the accessions in the test materials exhibited red seed coat colour (19.59%) whereas in the controls most of the accession showed cream seed coat (50%). Overall, the majority of the accessions exhibited cream seed coat colour with a frequency of 35.35%. The chi-square test of association between qualitative traits showed was 125 significant associations in the test materials whereas the controls only showed 3 significant associations. The overall population exhibited 162 significant associations. In the multiple correspondence analysis (MCA) terminal leaf shape, growth habit, pod curvature and raceme position mostly led to variation in the first dimension which accounted for inertia of 51.40%. Thirteen farmer and consumer-preferred traits were used in the MCA plot. Asontem, UG8 and UG30 had a close relationship with similar phenotypic classes in the first quadrant of the MCA plot. UG1 and UG81 were outliers and had a distant relationship with majority of the phenotypic classes of the selected traits. The test materials had a significantly higher mean than the controls for the following traits; number of pods per plant, number of locules, seed weight and seed yield but lower than the controls for the following traits; days to first flower, days to 50% germination, days to first mature pod and days to 50% mature pod. Furthermore, the test materials were significantly higher in mean concentration for the following amino acids; gallic acid and vanillic acid, glycine, l-histidine, l-aspartic acid, l-valine and l-methionine. A total of 191, 537 and 413 significant pairwise correlations were observed in the test materials, controls and entire population respectively for all quantitative traits. The multiple regression analysis revealed that the underlying determinant of yield was most influenced by yield and yieldrelated components in the test materials and controls with contributions of 100% and 36.67% respectively. Phytochemical traits made the highest contribution of 25.95% to influencing variation in yield for the entire population. The first six principal components in the morphological traits accounted for a total variability of 47.17%, 55.40 %, 42.99% in the test materials, controls and entire population respectively. The first three principal components in the phytochemical traits accounted for a total variability of 51.81%, 100 %, 53.14% of the total variation in the test materials, controls and entire population respectively. The biplot showed that the relationships among accessions and morphological, phytochemical and all traits explained 46.63% and 99.49 and 94.48 % of the total variance respectively. The canonical discriminant analysis grouped against yield showed that the first CV accounted for 17.19% and 40.82% for the respective morphological and phytochemical traits. The cluster analysis based on morphological and phytochemical traits clustered the 108 accessions into 7 and 6 major groups respectively. The genetic component studies showed that seed yield had a high genotypic (63.1%) and phenotypic (243.8%) variances but low heritability of 18.41% while phytochemical traits had high GCV (>20), PCVs (>20) and heritability (>80%). Based on the lowest RSI scores, the 10 best performing accessions with high yield potential among the population evaluated were UG84, UG24, UG44, UG69, UG47, UG14, UG70, UG66, UG36, UG102 . The marginal analysis revealed that no accession was significantly higher in yield than the overall mean. However, it confirmed cluster grouping of accessions based on trait similarities and dissimilarities.
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    Studies on the Role of the Coleopteran Species Callosobrochus Maculatus Fab., Sitophilus Zeamais Mots. And Tribolium Castaneum Herbst. In The Dispersal of Fungi among Stored Grains of Maize (Zea Mays L.) And Rice (Oryza Sativa L.) And Seeds Of Cowpea (Vigna Unguiculata Walp.) And Bambara Groundnut (Vigna Subterranea L.) Verdc]
    (University of Ghana, 1995-12) Badu-Yeboah, K.
    Seven Aspergillus species, A . clavatus, A . flavus, A.fumigatus, A. niger, A . ochraceus, A. sulpl1ureus and A. ustus have been used to investigate the role of three Coleopteran insect pests, namely, Callosobrochus maculatus, sitopl1ilus zeamais and Tribolium castaneum in the persistance and spread of contaminant fungi among grains of maize (Zea mays) and rice (oryza sativa) and seeds of bambara groundnut (vigna subterranea) and cowpea (Vigna unguiculata) . The Aspergillus species were among fungi isolated from the grains and seeds. Bambara groundnut seeds on saIe at Kaneshie , La, Madina, Makola and Mallam Atta markets in Accra district contained species of Absidia, Aspergillus, Cladosporium, Fusarium, Neurospora, Paecilomyces, Penicillium and PIll lularia. The dominant genera were Aspergillus and Penicillium represented by five and [our species, respectively, and the dominant species were Aspergillus flavus and Aspergillus niger . The predominant apecles of rowpea seeds from the same markets were Aspergillus £lnvus Jere Aspergillus oryzae, Cladosporium herbarum, Penicillium cl1rysogenum and Penicillium expansum. Although all the . seven As pergillus species could grow on insect body leachate agar prepared >J i th leacha te of the three insect pests, the conidia of some of them could germinate in the leacha te of only some of the insects. only A. flavus and A. ocl1raceus condidia germinated in all the three leachates. Germination of the conidia of all the species occurred , anY>Jay, in leachates containing extracts of various tissues of seeds (axis of the embryo , cotyledon and testa) and extracts of grains. Conidia of all the species germinated in solution of dissolved faecal pellets of Callosobrochus maculatus, while conidia of 11.. clavatus, A. ocl1raceus and A . sulplJureus only germinated in the solution of dissolved faecal pellets of Sitophilus zeamais and conidia of also three species, 11. . clavatus, A . flavus and A. ochraceus germinated in the solution of faecal pellets of Tribolium castaneum. Aspergillus flavus conidia adhering to the bodies of sitoplJilus zeamais and Tribolium castaneum were transported through maize grains packed in wide glass tubes. The amount of the conidia detached as the insects moved depended on the size of the spaces among the grains and the frequency of contact between the insects and the grains. s. zeamais lost 87.8, 8~.7 and 76.7 percent of the original load of conidia as the insects travelled over 100cm through grains measuring 5.3-8.3 x 4.04-7.3mm, 8.1-10.2 x 6.0-8.2mm and 9.5-12 . 2 x 7.5-9.5mm, respectively. The corresponding figures for conidia on T. castaneulll 'vere, 88.5, 87.9 and 82.8 per cent respectively. Dead insect bodies were invaded by many fungi despite the presence of large populations of sur face bacter ia. The colonyforming- units of bacteria recorded for C. lIlaculatus, S. zeamais and T. castaneum per ml of suspending medium immediately after death were 27 . 5 x 10', 281 x 10' and 104.5 x 10' respectively i and six days later they were 37.8 x 1~, 5.0 x 1~ and zero, respectively. On the sixth day, Aspergillus flavus was isolated from the bodies of all the three insect pests. In addition, Aspergillus niger, Mucor sp., Rhizopus sp. and Trichoderma Viride were isolatC2.cI ·: c_,: from C. lIlaculatus . , Aspergillus niger and Curvularia sp. from S. zeam~ is and Clasdosporiulll sp. from T. castaneulll. The mycelium growing in the bodies after death might have arisen from inoculum either on the surface of the body or in the gut . For, the gut of the insects had extensive mycoflora. Fourteen, thirteen and sixteen fungal species were isolated from the gut of C. maculatus, S. aeolllois and T. castaneum, respectively. The predominant genera were Aspergillus and Penicillium and five species, namely Aspergillus £lavus, Aspergillus fumigatus, Cladosporium herbarum, PellicilliJ.J.m citinum and Penicillium purpurogenum were isolated from the guts of all the three insect pests. Three Aspergillus species red experimentally to the insects persisted for different lengths of time in the guts. A. flavus was isolated 6,8, and 5 days respectively, after feeding the insects, from the guts of C. maculatus, s. zeamais and T. castaneum. The corresponding survival periods for A . fumigatus were 4,6 and 5 days respecti vely, and for A. oC/lraceus, 6,4 and 3 days respectively. It was concluded that products and dead bodies of the insects would contribute to the persistence of the contaminant fungi and living insects would be responsible for both persistence and dispersal of the fungi in stored grains and seeds. Persistence and dispersal of the fungi could be reduced by measures which control the insect pest popUlation, by periodic removal of dead insect bodies especially in comparatively smaller stocks kept i.n the markets and by exposure of the products to light to drive the insects to the dark base and discourage the frequent migration.
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    Prevalence of Mycotoxigenic Fungi and Mycotoxins (Ochratoxin A) in Dried Cocoa Beans
    (University of Ghana, 2020-10) Ashong, A.G.
    Concerns about levels of Ochratoxin A (OTA) detected in cocoa beans, its products, and the associated health issues with OTA contamination in cocoa is on the increase. This calls for the need for cocoa producing countries to research and obtain more data and information on the prevalence of Ochratoxigenic fungi present and OTA levels in dried cocoa beans, the raw material for chocolate and other cocoa products. This work sought to determine the moisture content of cocoa beans sampled from farm gates/ societies from licensed buying companies (LBC’s), determine the fungal loads and the occurrence of Ochratoxigenic fungi present as well as the Ochratoxin A levels in the cocoa beans sampled from four cocoa producing districts of the Central Region of Ghana; Agona Swedru, Assin Bereku, Assin Fosu and Breman Asikuma. Hundred (100) samples of dried cocoa beans were obtained from twenty (20) licensed buying companies (Five societies from each LBC). Moisture content of cocoa beans sampled was determined by The International Organization for Standards (ISO) method for moisture content determination. Pour plate method was used in isolating the fungi after surface sterilization with 0.6 % sodium hypochlorite. Fungal identification was done using morphological characteristics such as spore size, shape, and structure as well as colour, using Leica D500 microscope connected to Leica Application Suite (LASEZ) version 2.1. Ochratoxin extraction and quantification by solvent extraction and HPLC-FLD respectively. The method of extraction was partially modified and validated. The limit of detection (LOD) was found to be 1ng/Kg and the limit of quantification (LOQ) was 2ng/Kg. A linear range from 1.0 -20 ng/mL and a correlation coefficient (R2) of 0.9997 were obtained for the entire range of studied concentrations. Repeatability (RSDr) and reproducibility (RSDR) expressed as RSD were 5.5% and 9.8% respectively with mean recovery of OTA spiked at 2.5 and 5ng/kg in 10 replicates were consistent and more than 90%. Cocoa beans obtained from Unicom in the Assin Fosu district recorded the lowest moisture content value of 7.05% and the highest moisture content of 9.86% for the cocoa beans obtained from Nyonkopa in the Assin Bereku district. There were significant differences (P≤ 0.05) among the moisture content recorded for the cocoa beans obtained from the various LBCs. Fungal isolation and identification revealed the presence of fifteen (15) species belonging to eleven (11) genera isolated on Malt Extract Agar and Potato Dextrose Agar from cocoa beans obtained from the four districts sampled. The following species were encountered; Aspergillus (A. flavus, A. fumigatus, A. niger, A. parasiticus), Cladosporium (C. macrocarpum, C. sphaerospermum), Absidia corymbifera, Alternaria alternata, Byssochlamys nivea, Eurotium herbariorum, Mucor racemosus, Penicillium citrinum, Rhizopus stolonifer, Syncephalastrum racemosum and Talaromyces flavus. More species were isolated on Malt Extract Agar compared to Potato Dextrose Agar. Byssochlamys nivea and Talaromyces flavus were not isolated on PDA whilst Mucor racemosus, was also not isolated on MEA. Although all the cocoa beans obtained from the twenty (20) LBCs in the Agona Swedru, Breman Asikuma, Assin Fosu and Assin Bereku districts each recorded the presence of A. niger. Ochratoxin A was not detected in any of the cocoa beans obtained from these sources. Data obtained in this study indicated that most of the cocoa beans were not well dried to the recommended level of between 7% to 8% moisture content. Although some few species of fungi were isolated on both PDA and MEA and identified, only one potential Ochratoxigenic fungu, A. niger was identified and Ochratoxin A was not detected in any of the cocoa beans samples from the four districts. This may be due to the absence of the conditions necessary for the growth of fungi and development of OTA.
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    Prevalence of Mycotoxigenic Fungi and Mycotoxins (Ochratoxin A) in Dried Cocoa Beans
    (University of Ghana, 2020-10) Akwetey, G.A.
    Concerns about levels of Ochratoxin A (OTA) detected in cocoa beans, its products, and the associated health issues with OTA contamination in cocoa is on the increase. This calls for the need for cocoa producing countries to research and obtain more data and information on the prevalence of Ochratoxigenic fungi present and OTA levels in dried cocoa beans, the raw material for chocolate and other cocoa products. This work sought to determine the moisture content of cocoa beans sampled from farm gates/ societies from licensed buying companies (LBC’s), determine the fungal loads and the occurrence of Ochratoxigenic fungi present as well as the Ochratoxin A levels in the cocoa beans sampled from four cocoa producing districts of the Central Region of Ghana; Agona Swedru, Assin Bereku, Assin Fosu and Breman Asikuma. Hundred (100) samples of dried cocoa beans were obtained from twenty (20) licensed buying companies (Five societies from each LBC). Moisture content of cocoa beans sampled was determined by The International Organization for Standards (ISO) method for moisture content determination. Pour plate method was used in isolating the fungi after surface sterilization with 0.6 % sodium hypochlorite. Fungal identification was done using morphological characteristics such as spore size, shape, and structure as well as colour, using Leica D500 microscope connected to Leica Application Suite (LASEZ) version 2.1. Ochratoxin extraction and quantification by solvent extraction and HPLC-FLD respectively. The method of extraction was partially modified and validated. The limit of detection (LOD) was found to be 1ng/Kg and the limit of quantification (LOQ) was 2ng/Kg. A linear range from 1.0 -20 ng/mL and a correlation coefficient (R2) of 0.9997 were obtained for the entire range of studied concentrations. Repeatability (RSDr) and reproducibility (RSDR) expressed as RSD were 5.5% and 9.8% respectively with mean recovery of OTA spiked at 2.5 and 5ng/kg in 10 replicates were consistent and more than 90%. Cocoa beans obtained from Unicom in the Assin Fosu district recorded the lowest moisture content value of 7.05% and the highest moisture content of 9.86% for the cocoa beans obtained from Nyonkopa in the Assin Bereku district. There were significant differences (P≤ 0.05) among the moisture content recorded for the cocoa beans obtained from the various LBCs. Fungal isolation and identification revealed the presence of fifteen (15) species belonging to eleven (11) genera isolated on Malt Extract Agar and Potato Dextrose Agar from cocoa beans obtained from the four districts sampled. The following species were encountered; Aspergillus (A. flavus, A. fumigatus, A. niger, A. parasiticus), Cladosporium (C. macrocarpum, C. sphaerospermum), Absidia corymbifera, Alternaria alternata, Byssochlamys nivea, Eurotium herbariorum, Mucor racemosus, Penicillium citrinum, Rhizopus stolonifer, Syncephalastrum racemosum and Talaromyces flavus. More species were isolated on Malt Extract Agar compared to Potato Dextrose Agar. Byssochlamys nivea and Talaromyces flavus were not isolated on PDA whilst Mucor racemosus, was also not isolated on MEA. Although all the cocoa beans obtained from the twenty (20) LBCs in the Agona Swedru, Breman Asikuma, Assin Fosu and Assin Bereku districts each recorded the presence of A. niger. Ochratoxin A was not detected in any of the cocoa beans obtained from these sources. Data obtained in this study indicated that most of the cocoa beans were not well dried to the recommended level of between 7% to 8% moisture content. Although some few species of fungi were isolated on both PDA and MEA and identified, only one potential Ochratoxigenic fungu, A. niger was identified and Ochratoxin A was not detected in any of the cocoa beans samples from the four districts. This may be due to the absence of the conditions necessary for the growth of fungi and development of OTA.
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    Linkage Disequilibrium And Association Mapping Of Cowpea (Vigna Unguiculata (L.) Walp) Quantitative Traits
    (University of Ghana, 2020-10) Ajara, S.
    A genome-wide association study (GWAS) was conducted using 187 cowpea germplasm to study linkage disequilibrium and association mapping of some cowpea quantitative traits. All the accessions with the exception of two which were obtained from the Department of Plant and Environmental Biology, were assembled from International Institute of Tropical Agriculture Germplasm Resources Information Centre. These accessions comprised 94 cultivated types and 93 wild relatives. Data on morpho-agronomic traits were collected using the Cowpea Descriptor by the International Board for Plant Genetic Resources. A total of 32 morpho-agronomic traits and 46 SNPs markers were assessed. Ethanol extracts of pulverized dried cowpea seeds were used to determine the amino acid concentrations. Data analysis involved descriptive statistics, Pearson’s correlation, principal component analysis (PCA), cluster analysis, Nei’s genetic diversity of subpopulations, likelihood ratio test for Hardy Weinberg equilibrium, F statistics and gene flow, population structure and genetic distance analysis. High variation was observed in the morpho-agronomic traits. A total of one hundred and thirty-six (136) significant pairwise correlations were observed in the quantitative traits. Out of the forty-six (46) SNPs markers, forty-three (43) were polymorphic. Means for the quantitative traits studied were as follows: days to 50% germination was 3.93±0.26 days. Mean days to first leaf stage was 12.40±0.24 days. Mean chlorophyll content was 1.44±0.02 mg/liter. Mean days to 50% flowering was 65.97±1.97 days. Mean number of flowers per plant was 8.95±0.55 flowers. Mean peduncle length per plant was 13.39±0.45 cm. Mean number of pods per peduncle was 1.97±0.01 pods. Mean days to 50% pod maturation was 81.86±1.97 days. Mean number of pod per plant was 7.09±0.54 pods. Mean pod length per plant was 11.53±0.28 cm. Mean average seed per pod was 9.86±0.24 seeds. Mean 20 seed weight was 1.5580±0.07 grams. Mean seed yield per plant was 70.31±5.65 seeds. Mean seed abortion rate per plant was 2.14±0.08 percent. All the 19 amino acids analyzed for the seed quality traits were present in the accessions, except L-Cysteine which was beyond detection. However, some accessions recorded 0.00 for Iso-Leucine and Trans-4-Hydroxyl-Proline. Mean concentrations for the amino acids was generally low in the wild relatives. It ranged between 21623.03±5299.45 x 10-5 ppm (L-Tryptophan) to 17.52±5.36 x 10-5 ppm (L-Methionine) while that for the cultivars varied from 3953909.00±7143.39 x 10-5 ppm (L-Tryptophan) to 18266.33±2524.18 x 10-5 ppm (L-Methionine). Mean Nei’s genetic diversity for the overall population was 0.3001, mean Wright’s Fixation coefficient for inbreeding (FIS) was 0.8935, mean degree of differentiation within population (inbreeding at different level) (FIT)was 0.9143, mean degree of genetic differentiation (FST) was 0.1952, mean gene flow (Nm) was 1.0309, mean observed heterozygosity was 0.0242 and mean frequency of cross pollination (C) was 0.0805. Analysis of population structure grouped the cowpea accessions into two clusters. Proportion of membership for cluster 1 was 0.551 and that for cluster 2 was 0.449. The mean FST value for cluster 1 was 0.064 and that for cluster 2 was 0.048. Intra chromosomal linkage disequilibrium estimate for SNPs loci revealed 12.64% and 15.38% at the threshold level of r2 ≥ 0.1 and r2 ≥ 0.05 respectively. The largest LD block observed was 25.0 bp between SNPs markers 6904_1061 and 9815_2051 at correlation co-efficient measure of variability between two loci (r2) of 0.10 and the difference between the gamete frequencies at two different loci (D’) of 0.89. Partial linkage disequilibrium decay was observed from a graph of r2 values of LD (between 0.0 and 0.75) against map distance ranging from 0.0 to 38.75 cM. Significant marker-trait associations were identified with very high potential for exploitation in marker-assisted breeding for the important traits in cowpea. Number of flowers per plant, mean peduncle length, number of pods per peduncle, number of pods per plant, seed yield per plant and DL-Beta phenyl-Alanine were associated with different SNPs markers at 5 cM map distance while 20 seed weight, D-Proline, Iso-Luecine, L-Histidine and L-Serine were associated with different SNP markers at 0.0 cM map distance.
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    Survey of Some Mushroom Farms in the Greater Accra and Central Regions; their Mycological Quality Profile and the Pathogenic Role of Trichoderma Harzianum in the Production of Pleurotus Ostreatus
    (University of Ghana, 2020-10) Adalete, E.K.
    The environmental and farm aerial quality as well as the mycological purity of the basic ingredients employed for mushroom production in a mushroom farm is a sine qua non for producing healthy sporophores and gaining financial profit from the capital investment made by the producer of the oyster mushroom. In this study, seven mushroom farms in the Greater Accra Region (Ogbojo, Nii-Boi Town, Lapaz, Adenta, Ashaley Botwe, Anyaa-Awoshie) and Kasoa in the Central Region (Kasoa) were selected to provide a baseline data to help prescribe appropriate practical scientific interventions to help curb the financial losses incurred by farmers. The seven farms were; E90 Mushroom Farm, Ogbojo; Kwesi-Babs Farm, Kasoa; Immaculate Gold Enterprise, Nii-Boi Town, Lapaz; Delabless Mushroom Farm, Adenta; 4E Mushroom Farm, Ogbojo/Ashaley Botwe; Edeyef Mushroom Farm, Anyaa-Awoshie and PCM Mushroom Farm, Ashaley Botwe. The following criteria of quality were used to assess the farms; a. Resident mycoflora in the fruiting bodies produced on the farms using the conventional fungal population enumeration technique on three media (PDA, OGYE and DRBC) b. Quality of the composted growth substrate (sawdust) to ascertain species diversity of resident fungi using Decimal Dilution Technique. c. Aeromycoflora in the seven cropping rooms of the farms using the Open Plate Exposure method with the view to ascertaining the most predominant fungal species. d. In order to assess the control method for the most ubiquitous green mould causing losses in the farm house, the causative fungus Trichoderma harzianum was cultured on Potato Dextrose Agar (PDA) and in Potato Dextrose Broth (PDB) amended with varying dilutions (1:1 – 1:10v/v) of the ethanol bark extract of Anthocleista nobilis and a copper fungicide, “Champion”. e. Assessment of the growth yield and Biological Efficiency (BE) of Pleurotus ostreatus cultivated on already spawned substrate bags contaminated with T. harzianum and pre-spawned uncontaminated substrate bags. f. Mineral composition and proximate analysis of fruiting bodies employing the AOAC methods. The resident mycoflora in the mushroom fruiting body was unique for each of the selected seven (7) farms. Fungi belonging to ten (10) genera and fifteen (15) species namely Aspergillus (A. alutaceus, A. candidus, A. flavus, A. fumigatus, A. terreus), Cladosporium (C. herbarum, C. macrocarpum), Fusarium oxysporium, Gliocladium sp., Penicillium (P. brevicompactum, P. citrinum), Rhizopus oryzae, Talaromyces flavus, Trichoderma harzianum, Saccharomyces spp., and Rhodotorula mucilaginosa were encountered. Aspergillus species (6) predominated over the others followed by Cladosporium (2) and Penicillium (2). Trichoderma harzianum was the most ubiquitous fungus on the fruiting bodies isolated from all the seven (7) mushroom farms.The mean fungal population in the fruiting bodies were: T. harzianum (4.13 log10CFU/g); A. flavus (3.86 log10CFU/g); A. niger (4.10 log10CFU/g); A. fumigatus (3.60 log10CFU/g); A. candidus (3.30 log10CFU/g); A. terreus (3.20 log10CFU/g); P. brevicompactum (3.5 log10CFU/g); C. herbarum (4.20 log10CFU/g); C. macrocarpum (3.78 log10CFU/g); R. oryzae (2.53 log10CFU/g); Saccharomyces spp. (4.08 log10CFU/g); F. oxysporium (3.16 log10CFU/g). The fungal flora in the composted growth substrate (sawdust) belonged to eighteen (18) species spread through ten (10) genera. Aspergillus species (A. candidus, A. flavus, A. fumigatus, A. niger). A. fumigatus predominated. Other species isolated were Cladosporium (C. herbarum, C. macrocarpum), Didymella sp. Fusarium poae, Penicillium (P. brevicompactum, P. camemberti) Rhizopus oryzae, Trichoderma harzianum, Rhodothorula mucilaginosa, Saccharomyces spp. (yeast), Verticillium fungicola and Mycelia sterilia. Again, the species encountered were common and unique for each farm visited. The aeromycoflora isolated belonged to nineteen (19) species and twelve (12) genera and was predominated by Aspergillus species (A. candidus, A. flavus, A. niger, A. oryzae, A. parasiticus) followed Penicillium (P. citrinum, P. brevicompactum), Cladosporium (C. herbarum, C. macrocarpum), Fusarium (F. oxysporium, F. poae). Single species encountered were Epicoccum nigrum, Gliocladium sp., Mycelia sterilia, Rhodotorula mucilaginosa, Rhizopus oryzae, Trichoderma harzianum, Verticllium fungicola and Saccharomyces spp. (yeast). Radial growth of T. harzianum on PDA amended with different dilutions of A. nobilis showed that growth was commensurate lowering of depression of growth with decreasing concentration of extract. The higher the concentration, the severe the depression but the mycelium of T. harzianum cultured in different concentrations of the extract of A. nobilis approximated that of the control after 10 days. In the case of the copper fungicide, ‘Champion’ only the 1:5 and 1:10 v/v dilutions approximated the control after 10 days of incubation whilst the undiluted and 1:1 v/v dilutions suppressed growth by 60-70% in 10 days. Vegetative growth of the fungus in A. nobilis and ‘Champion’ fungicide followed the trend obtained on the agar. Infection of the fruiting body reduced the elemental composition of Calcium, Copper, Iron, Potassium, Magnesium, Sodium, Phosphorus and Zinc. The proximate analysis also showed a reduction in parameters of the following: Dry matter (%), Moisture (%), Fat (%), Crude fibre (%), Crude protein (%), Total ash (%), Carbohydrate (%) and Energy (kcal/100g). The practical implication of the finding is discussed and future work suggested.
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    Studies On The Mycoflora Of Grains Of Maize (Zea Mays L.) And The Survival Of The Contaminant Aspergillus Species
    (University of Ghana., 1995-10) Kesse, R.E.O.
    Grains of Zea mays in storage at the Kaneshie and Tema warehouses of the Ghana Food Distribution corporation with atmospheric humidity fluctuating between 55 and 90% R. H. and those stored at 40°C in the Botany Department were attacked by a large number of fungi. Non-stackburn and stackburn grains at the Kaneshie warehouse contained 26 and 16 fungal species, respectively, and those in Tema warehouse had 32 and 19 species, respectively. Aspergillus was the dominant genus of the mycoflora and Aspergillus flavus was the predominant species occurring at very high levels. The moisture content of the grains stored in the warehouses showed, an average rise of 6.9 per cent within the six months of storage. During this period the percentage occurrence of A.flavus consistently rose to a peak at the end of the 4th month and declined. Paecilomyces puntonii and Paecilomyces variotii were consistently present in the early months of storage and then disappeared. The rest of the species taking all four batches of grains together, did not show a consistent pattern of occurrence. The air spora of the Kaneshie and Tema warehouses consisted of 26 and 27 fungal species, respectively, with the same difference in the dominant species. The most abundant species recorded in the Kaneshie warehouses in descending order were Aspergillus flavus, Ciadosporium herbarum, Aspergillus flavus-oryzae, Mucor sp., Aspergillus fumigatus, Rhodotorula sp . , Penicillium expansum, Aspergillus niger and Penicillium chrysogenum. On the other hand, the most abundant species in the Tema warehouse in descending order were Cladosporium herbarum, Aspergillus flavus, Penicillium expansum, Penicillium chrysogenum, Rhodotorula sp., Rhizoctonia solani, Aspergillus parasiticus and Paecilomyces puntonii. Grains of Abeleehi, Mixed White, Obatanpa and Yellow maize varieties stored at 40°C had 15, 16, 18 and 18 contaminant fungal species despite marked average loss of 41 .4 per cent moisture content over the storage period of 4 months. Aspergillus flavus, under those conditions, was again the predominant species. Experiments which investigated growth, sporulation, conidial germination capacity, and conidial survival in Aspergillus clavatus, Aspergillus flavus, Aspergillus niger and Aspergllus tamarii, showed significant physiological differences among the species. A. clavatus grew best at 38°C and sporulated best at 26˚C; it also grew best at 62 .4 - 7 3.4% R. H., and sporulated best at 85.2 - 100%- R.H . , conidia formed at 62 4 - 100% R. H. showed 90.0 - 99 .5 per cent germination in Potato Dextrose Broth and more than 69.6 per cent germination in 1 .0 Dextrose, 1 .0 .Sucrose and 1 .0 Peptone solutions, and more than 22.2 per cent ln exudates of grains of three maize varieties, but did not germinate ln water. The conidia of the other three species did not also germinate in water. The humidity at which the conidia were formed did not affect their rate of loss of vigour in storage. The conidia survived best at 0,60 and 100% R.H. and lost vlabl1lty quickest at 20 and 80% R.H. A flavus grew and sporulated best at 34°C; grew best at the humidities of 73 .4 - 92.8% R.H. and sporulated at 100% R.H. Conidia formed at 62.4 - 100% R.H . showed 80.7 - 94.3 per cent germination in Potato Dextrose Broth and more than 11 per cent germination in maize grain exudates but did not germinate in 1.0% Dextrose, 1.0% Sucrose and 0.1% Peptone solutions. The humidity at which the conidia were formed did not affect their rate of loss of vigour in storage. The conidia survived best at 0, 20, 40, and 100% R.H. and lost viability quickest at 80% R.H. A. niger grew and sporulated best at 34°C; grew best at the humidities of 92.8 and 100% R.H. and sporulated best at 62.4 - 92.8% R.H. Conidia formed at 62.4 - 100% R.H. showed 83.4 - 98.4 per cent germination in Potato Dextrose Broth but did not germinate in maize grain exudate, and in 1.0% Dextrose, 1.0% Sucrose and 0.1% Peptone solution. Conidia formed at 73.4 - 85.2% R.H. apparently had a greater potential for survival than those formed at the other humidities. A. niger conidia survived longest at 100% R. H. and longevity decreased with decreasing relative humidity. A· tamarii grew and sporulated best at 30°C; grew best at 62.4 - 73.4% R.H. and sporulated best at 62.4% R.H. Conidia formed at 62 . 4 - 100% R.H. showed 87.7 - 98.6 per cent germination in Potato Dextrose Broth but did not germinate in maize grain exudate nor in 1.0% Dextrose, 1.0% Sucrose and 0.1% Peptone solutions. Conidia formed at 65.0 85.2% R.H. seemingly had a greater potential for survival than those formed at the other humidities. A. tamarii survived longest at 0, 20, 40, and 60% R.H. and lost viability quickest at 100% R.H. Conidia of all the four species which were swollen prior to germ tube development and were then air-dried died within 1-6 hours. It was concluded that because of the variation in response of the fungl to temperature and humidity, warehouses held at a set temperature and relative humidity would not be able to control fungal contamination of the grains. More resistant fused pericarp and testa which could emerge from breeding programmes may be one of the more efficient ways by which invasion of the gralns could controlled.
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    Studies on Effect of Decomposing Products of Leaf Of Cocoyam (Xanthosoma Mafaffa Schott.) On Phytophthora Palmlvora (Butl.) Butl.
    (University of Ghana., 1978-04) Takyi, N.K.
    Germination of P.palmivora sporangia and zoospores, growth of the hypha and formation of the sporangia in the presence of decomposing leaves of cocoyam were investigated. Cocoyam leaves buried in soil, from an experimental cocoa plot at the Cocoa Research Institute at Tafo, were rapidly decomposed and they completely rotted in 12 days. Fungal species belonging to the genera Alternaria, Aspergillus, Cladosporium, Curvularia, Fusarium, Penicillium, Rhizopus and Trichoderma were isolated from the decomposing cocoyam leaves. Two of the fast growing species, Rhizopua oryzae and Rhizopus stolonifer, were selected and used as agents for decomposition of the cocoyam leaves under sterile conditions. Decomposition of the cocoyam leaves in the laboratory was carried out at 25°C and 30°C, the respective optimum temperatures for growth of R.oryzae and R.stolonifer. Growth by both species in Cassava-dextrose broth at the optimum temperature caused a shift in the pH of the medium from pH 5.30 to around pH 2.30. Culture filtrates of these fungi were therefore adjusted to neutral pH in experiments in which they were used. Direct germination of P.palmivora sporangia was greatly stimulated, by about 400 per cent, by both Rhizopus culture filtrates. Large number of germ tubes emerged from sporangia growing in the culture filtrates of the Rhizopus species. Zoospore germination was also improved by at least 30 per cent by culture filtrates of both R.oryzae and R.stolonifer. R.stolonifer greatly stimulated vegetative growth of P.palmivora, whilst R.oryzae slightly suppressed it. Direct germination of P.palmivora sporangia was stimulated by exudate of undecomposed dry cocoyam leaves; germination in the exudate and in distilled water was 54.9 and 15.3 per cent, respectively. Indirect germination and zoospore germination were, however, inhibited by about 80 and 50 per cent, respectively, by the leaf exudate. Vegetative growth on Cassava-dextrose agar containing different concentrations was slightly improved whilst sporangial formation was depressed. . Direct germination of P.palmivora sporangia at 30°C Was inhibited by extracts of Rhizopus-decomposed cocoyam leaves. Amendment of the R.oryzae-decomposed leaf extract with Fructose Glucose, Maltoso or Sucrose negated the inhibitive influence. ' sodium nitrite, Asparag1ne and Ammonium tartrate also improved direct germination in the R.oryzae-decomposed leaf extract, but addition of asparagine caused further inhibition. The Rhizopus-decomposed cocoyam leaf extract slightly inhibited indirect germination of P.palmivora sporangia at 20°C. With the exception of Fructose at 1.0 percent with improved germination there was greater depression of germination in R.oryzae-decomposed cocoyam leaf extracts amended with Glucose, Maltose and Sucrose of concentrations of 1.0, 2.0, 3.0 and 4.0 per cent w/v or with Ammonium nitrate, Peptone and Sodium nitrate at 0.5, 1.0 and 1.5 per cent. Asparagine improved indirect germination only at 0.5 per cent concentration, but slightly suppressed it at higher concentrations of 1.0 and 1.5 per cent. Zoospore germination was slightly inhibited by Rhizopus - decomposed cocoyam leaf extract. The inhibition was annulled by Fructose, Glucose, Maltose and Sucrose. Higher concentrations of Peptone and Sodium nitrate, at 1.5 per cent, supported even poorer germination than the unamended extract, but germination at the lower concentrations of 0.5 and 1.0 per cent in Ammonium tartrate and Peptone-amended extract was superior. The zoospores of P.palmivora diSintegrated in extract of R.oryzae-decomposed cocoyam leaf extract of pH 4.0. Germination improved gradually from 40.9 to 79.3 per cent on raising the pH of the extract from pH 5.0 through 9.0. Optimum sporangial germination occurred at pH 7.0 and gradually decreased as the pH moved away from the optimum to both the alkaline and acid ends of the pH range. There was germination at the extremes, pH 4 and pH 9, used. Extracts of leaves decomposed by either Rhizopus species slightly improved vegetative growth of P.paluivora on Cassava dextrose agar but depressed sporulation with increase in concentration, from 5.0 to 20.0 per cent. An aqueous extract of soil from the same plot at the Cocoa Research,Institute Tafo only slightly reduced direct sporangial germination at 30 C and zoospore germination but did not affect indirect germination at 20˚C nor vegetative growth and sporangial formation in P.palmivora. However, extract of the soil containing decomposed cocoyam leaves substantially decreased zoospore germination from 14.6 per cent in the control of distilled water to 2.9 per cent., Direct sporangial gemination was similarly reduced from 40.2 in distilled water to 7.7 per cent in the extract. Vegetative growth remained unaffected but sporulation was reduced slightly at higher concentrations (15.0 and 20.0 per cent v/v) of the extract. The decomposition products of cocoyam leaves contained very little nutrients. Although Glucose, Fructose, Mannitol and Sorbitol were identified, by paper chromatography, in the exudate of dry cocoyam leaves, at concentrations of 5.0 - 7.0, 6.0 - 7.0, 2.0 - 3.0 and less than 1.0 microgram per gram of dry leaf, respectively, only Trehaloso,at 18.0 - 20.0 microgram per gram, was identified in the Rhizopus-decomposed leaf extract. The amino acids, Alanine, Amino-butyric acid and Asparagine were also identified, by paper chromatography, at concentrations of 1.0 - 2.0, less than 1.0 and 2.0 - 3.0 microgram per gram, respectively, in the exudate of dry cocoyam leaves but none was detected in the Rhizopua-decomposed leaf extract.