Browsing by Author "Appiah, A.S."
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Item Field evaluation of tomato varieties/breeding lines against tomato yellow leaf curl virus disease (TYLCV)(Pertanika Journal of Tropical Agricultural Science, 2018-02) Segbefia, M.M.; Amoatey, H.M.; Ahiakpa, J.K.; Quartey, E.K.; Appiah, A.S.; Nunoo, J.; Kusi-Adjei, R.Tomato Yellow Leaf Curl Virus (TYLCV) is currently the most devastating virus of cultivated tomatoes in tropical and subtropical regions, accounting for significant yield losses in cultivated tomato in Ghana. Severe population outbreaks of the whitefly vector (Bemisia tabaci), are usually associated with high incidence of the disease. Resistance breeding is the surest solution to TYLCV in developing viable seeds for increased tomato production in Ghana. The Wild tomato (Solanum pimpinellifolium L.) is a recognised crop Wild species (CWS) with resistance genes to different diseases including the TYLCV disease and possesses good fruit quality traits in Ghana. Three (3) cultivated tomato varieties and seven breeding lines developed from crosses between the Wild tomato and three hybrids, three backcrossed lines and the Wild tomato were evaluated with their parents against TYLCV disease under local field conditions. Field appraisal of whitefly populations, disease incidence and severity, agronomic and yield characteristics of the tomato varieties/breeding lines were undertaken to hasten selection of tolerant/resistant varieties or breeding lines in the breeding programme. Wild tomato (ISSAP = 0.31 and ISSDP = 0.76) and Woso (ISSAP = 1.90 and ISSDP = 2.27) recorded the least and highest average symptom severity on all plants (ISSAP) and diseased plants only (ISSDP); while the least and highest disease incidence was recorded by the Wild tomato (11.10%) and Roma (43.05%). Roma which recorded the highest population of whiteflies in the dry season also exhibited the highest symptom severity on all plants as well as diseased plants during the study period. There was a significant symptom relapse in Wild tomato and Woso x Wild in 6-8 WAT for both ISSAP and ISSDP. Number of fruits per plant, ISSAP and ISSDP were positively and/or inversely correlated (r = 0.98, 0.93, -0.83) with average whitefly count, percent disease incidence and yield (t/ha).Item Incidence of sweet potato viruses in the coastal savannah agro-ecological zone of Ghana(Journal of Plant Pathology, 2015-05) Sossah, F.L.; Appiah, A.S.; Oduro, V.; Amoatey, H.M.; Owusu, G.K.; Oppong, A.; Lamptey, J.N.L.; Carey, E.E.; Fuentes, S.An experiment was conducted under field conditions to assess the incidence of viral diseases in 20 accessions of sweet potato [Ipomoea batatas (L.) Lam.]. Using symptomatology, biological indexing, nitrocellulose membrane ELISA (NCM-ELISA) and PCR, the accessions were assessed for disease incidence and symptom severity. Symptom expression varied among the accessions with severity index ranging from 2.24 in UK/BNARI at eight weeks after planting (wap) to 3.63 in US029 at 12 wap. Mean disease incidence varied significantly among the accessions, ranging from 43.2% to 96.3%. Using NCM-ELISA, 85% of the sweet potato plants tested positive to Sweet potato feathery mottle virus (SPFMV), Sweet potato mild speckling virus (SPMSV, 55%), Sweet potato collusive virus (SPCV, 45%), Sweet potato chlorotic fleck virus (SPCFV, 30%), Sweet potato virus G (SPVG, 20%), Sweet potato mild mottle virus (SPMMV, 5%), Sweet potato chlorotic stunt virus (SPCSV, 1.67%) and Cucumber mosaic virus (CMV, 1.67%). PCR detected Sweet potato leaf curl virus (SPLCV) in accessions UK/BNARI and CRI054. Biological indexing resulted in characteristic symptoms, commonly vein-clearing with eventual death of plants grafted with scions mix-infected with SPCSV and SPFMV. This work provides the first detailed report on sweet potato virus diseases in Ghana correlating symptoms, grafting, serology as well as PCR. It emphasizes the importance of selecting resistant cultivars as planting materials and the enforcement of quarantine measures to minimise the introduction of viruses into Ghana and their subsequent spread. © 2015, Journal of Plant Pathology. All rights reserved.Item Intra-specific variation in West African and Asian germplasm of okra (Abelmoschus spp L.)(Science Direct (Annals of Agricultural Science), 2017-09-28) Ahiakpa, J.K.; Magdy, M.; Werner, O.; Amoatey, H.M.; Yeboah, M.A.; Appiah, A.S.; Quartey, E.K.; Ros, R.M.Ten quantitative agromorpho-economic traits, six inter-simple sequence repeat (ISSR) primers, and three sequenced regions were employed to study intra-specific genetic diversity among twenty-eight accessions of West African and Asian okra (Abelmoschus spp L.) collected from eight geographical regions of Ghana. Pod yield per plant was analysed as dependent variable in relation to other agromorphoeconomic traits, showing the correlation and contribution of each trait to crop yield. 50% germination and flowering were the most significant traits followed by plant height and average seeds per plant. Principal coordinate analysis defined three sets of traits, while Agglomerative Hierarchical Clustering (AHC) defined three clusters of the germplasms. ISSR detected very low level of polymorphism among the accessions. Testing the correlation between molecular data and morphological traits using Mantel test showed a significant positive correlation (r-value = 0.71, 0.90) with 50% flowering, fruiting and number of leaves per plant. Eclectic variation between Indiana and the rest of the accessions for both agromorpho-economic traits and molecular markers affirms its potential usefulness as a source of diverse genes for future breeding programmes. Sequencing of regions from all accessions, suggests that they are identical with a common ancestry. Outcomes of this study is timely for an ongoing okra hybridisation programme in Ghana.Item Isolation and characterization of crude-oil-dependent bacteria from the coast of Ghana using oxford nanopore sequencing(Heliyon, 2023) Sarfo, M.K.; Gyasi, S.F.; Kabo-Bah, A.T.; Adu, B.; Mohktar, Q.; Appiah, A.S.; Serfor-Armah, Y.The utilization and improper use of crude oil can have irreparable damage on the environment and human populations. This study sought to isolate hydrocarbon utilizing bacteria from 1% v/v pristine seawater and 1% v/v crude oil using enrichment culture techniques. Whole genome sequencing of DNA using the Oxford Nanopore sequencing technique with Fastq WIMP as the workflow at 3% abundance was undertaken. The results showed that the most abundant isolates identified using this technique at specific sampling sites were, Acinetobacter junii (51.9%), Alcanivarax pacificus (15.8%), Acinetobacter haemolyticus (21.6%), Pseudomonas aeruginosa (23.4%), Alcanivorax xenomutans (24.7%), Alcanivorax xenomutans (23.0%) Acinetobacter baumannii (40.0%) and Acinetobacter junii (14.2%). Cumulatively, the most abundant isolates in the 8 sampling sites were Acinetobacter junii (17.91%), Alcanivorax xenomutans (11.68%), Pseudomonas aeruginosa (7.68%), Escherichia coli (7.67%), Acinetobacter haemolyticus (3.40%), and Alkanivorax pacificus (3.10%). Spearman’s rank correlation analysis to examine the strength of relationship between the physicochemical parameters and type of bacteria isolated, revealed that salinity (0.8046) and pH (0.7252) were the highest. Isolated bacteria from pristine seawater, especially Escherichia coli have shown their capacity for bioremediating oil spill pollution in oceanic environments in Ghana.Item Physiological changes associated with Okra mosaic virus infection in field grown okra plants(AJAB, 2021) Amiteye, S.; Appiah, A.S.; Boateng, F.; Kutufam, J.T.; Amoatey, H.M.As a prerequisite for the breeding of virus-resistant okra cultivars, the effect of Okra mosaic virusinfection on physiological performance of ten okra cultivars were assessed under field conditions within the coastal savannah agro-ecological zone of Ghana. All cultivars succumbed to the disease and expressed varying degrees of symptoms. The results showed that plant height at initial and 50% flowering were significantly reduced with cultivar Clemson spineless showing the highest reduction of 38% and 35% respectively. Plant height at 50% podding was also reduced in all cultivars with the highest reduction (40%) occurring in cultivar Clemson spineless. Virus-infected plants of cultivars Kwabenya 1, Labadi dwarf and Asutem took on the average 43 days to attain 50% flowering compared to 25 days in healthy or control plants. Diseased plants had significantly (P<0.05) delayed, taking on the average 47 days after planting to attain 50% podding compared to the control plants with an average of 35 days. Infected plants of cultivars Kwabenya 1 and Labadi dwarf took the highest number of 51 days to attain 50% podding. Pod length and width were also reduced in all cultivars but were highest in cultivars Lucky 19 F1 and Clemson spineless at 52.19% and 46.25% respectively. Based on this assessment, cultivars Adom and Asutem which were less affected in terms of disease severity and fruit yield reduction could be exploited in future breeding programmes.