Browsing by Author "Kusi-Adjei, R."
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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 The use of Microsatellite Markers in Genetic Variation Analysis of Some Introduced Rubber Tree (Hevea brasiliensis) Clones Cultivated in Ghana(2018-12) Antwi-Wiredu, A.; Amiteye, S.; Asare, A.T.; Kusi-Adjei, R.; Diawuoh, R.G.; Aryee, C.O.; Klu, G.Y.P.Purpose: Genetic makers are indispensable in the genetic quantification and characterization of plant species of which rubber tree is no exception. Markers have been used severally in genetic identification and diversity analysis of rubber tree species. However, in Ghana genetic diversity and relatedness among introduced rubber tree species are limited. The study is aimed to use microsatellite markers to assess the genetic variability and evaluate genetic relationships among clones of Hevea brasiliensis cultivated in Ghana. Research Method: Genomic DNA was extracted from fresh rubber leaves following the Cetyltrimethyl Ammonium Bromide (CTAB) protocol. The five (5) different SSR primers used for the analysis were hmct1, hmac4, hmct5, gSSR212 and gSSR194. Findings: The five SSR markers showed some degree of relatedness among the rubber clones which suggested genetic similarity (IRCA317-5, IRCA41-2, IRCA331-6, IRCA230-4, IRCA109-3, and B8-23) and diversity (K2-18, IRCA840-7, PB217-8, PB217-10, and IRCA317-16) among the clones irrespective of their geographical area of collection. Research Limitation: The unavailability of polivinylpolipyrolidon (PVPP) and polyacrylamide gel (PAGE). Original Value: The results from the study depict that relatively some rubber clones of interest could be selected for future breeding and propagation programmes in Ghana.