Browsing by Author "Tushemereirwe, W. K."
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Item Banana field resistance to insect-vector transmission of bacterial wilt caused by Xanthomonas campestris p.v musacearum(African Journal of Agricultural Research, 2019) Mudonyi, B.; Vanhaelewyn, L.; Tusiime, G.; Ssekiwoko, F.; Kubiriba, J.; Tushemereirwe, W. K.; Changa, C. M.Banana, a major staple in East and Central Africa is constrained by banana Xanthomonas wilt (BXW) caused by Xanthomonas campestris pv. musacearum (Xcm). Xcm-infected plants are rapidly destroyed leading to 100% yield loss. Cultural controls are effective but laborious attracting laxity among farmers. This has led to epidemic resurgence in areas where BXW had been contained hence spread to new regions. Reliable control option would be planting Xcm-resistant varieties but extensive germplasm evaluation for their identification has not been conducted. Objective therefore was to determine existence of Xcm-resistance in banana by evaluating major banana cloneset representatives among indigenous cultivars plus introduced foreign Musa accessions. Potted plants were artificially inoculated with 0.5 ml (108CFU) of Xcm suspension. Promising selections from pot trial were later evaluated under natural transmission in field. Field trial plants were infected via insect vectors from spreader plants of highly susceptible cv Kayinja infected by spraying flowers with Xcm. Severity of Xcm-infection was semiquantified using scales 1-5 and 0-5 for pot and field screening trials respectively. This enabled calculation of disease index as a measure of resistance for each genotype. High index implied highly susceptible banana genotype and low index resistant genotype. Findings 44 days after artificial inoculation showed wild banana M. balbisiana had 0.0 disease index thus highly resistant. All other banana genotypes tested under similar conditions had disease index of 100 thus susceptible. In field (insect vector transmission), disease index varied significantly among various genotypes evaluated, some susceptible while others; M. balbisiana, Mbwazirume, M9 and M. Zebrina resistant throughout 360 days of observation. We recommend that heritable traits that confer resistance in M. balbisiana, Mbwazirume, M9 and M. zebrina to Xcm be identified for utilization in genetic modification of farmer preferred bananas. Varieties Mbwazirume and M9 should be promoted for farmer growing to complement cultural controls against BXW.Item Banana influences on differential expression of hypersensitive response and pathogenicity gene f (hrpf) in Xanthomonas campestris pv. musacearum(African Journal of Biotechnology, 2017) Mudonyi, B.; Tusiime, G.; Kubiriba, J.; Tushemereirwe, W. K.; Changa, C. M.Banana Xanthomonas wilt is a devastating disease of cultivated banana in East and Central Africa, manifesting as initial leaf wilting, premature fruit ripening and eventual death of all infected plants leading to total yield loss. In order to contribute towards development of effective disease control options, hrpf expression by Xanthomonas campestris pv musacearum (Xcm) during establishment of Xanthomonas wilt infection was determined. To successfully initiate infection, plant pathogenic bacteria deliver effector proteins into host cells using specialized protein transport system such as the Type III secretion system (TTSS). It is a syringe needle-like translocation apparatus essential for delivery of effector proteins into the host cells and hypersensitive response and pathogenicity gene f (hrpf) encodes one of the structural proteins for effector protein delivery. In this study, hrpf expression by Xcm during establishment of Xanthomonas wilt infection was determined in minimal medium amended with extracts from susceptible banana genotypes and banana host plants. Total RNA was isolated from Xcm recovered from inoculated plants and also from minimal medium amended with banana extracts; cDNA synthesised and hrpf amplified by PCR using gene specific primers. Findings showed that Xcm multiplied in susceptible host banana and minimal medium amended with their extracts but not in resistant M. balbisiana and its extract. hrpf gene was thus amplified from cDNA samples of susceptible banana genotypes and their extracts suggesting its expression and involvement in the successful establishment of Xanthomonas wilt disease by Xcm.Item Comparison of damage levels caused by Radopholus similis and Helicotylenchus multicinctus on bananas in Uganda(Annals of Applied Biology, 2000) Barekye, A.; Kashaija, N.; Tushemereirwe, W. K.; Adipala, E.Field surveys were done in 1997 and 1998 in Masaka district, Uganda, an area which is experiencing a decline in banana production, to assess level of damage caused by nematodes Radopholus similis and Helicotylenchus multicinctus at farm level. Ten farms within a radius of 2 km were selected and nematode damage assessed. The major nematodes encountered were Pratylenchus goodeyi, R. similis and H. multicinctus. P. goodeyi and H. multicinctus were more abundant than R. similis but R. similis had a stronger and significant correlation with root damage. A subsequent pot trial examined pathogenicities of R. similis and H. multicinctus in pure and mixed cultures on tissue cultured-banana plantlets. R. similis alone and in mixed population reduced root fresh weight significantly, and the percentage of root necrosis ranged between 22.8-41.6% and 18.3-45.5% for March 1998 and March 1999 trials, respectively. The difference in damage caused by R. similis alone and in mixed population was not statistically significant, and was higher than the damage caused by H. multicinctus alone. There were no significant differences in pathogenicity among the R. similis isolates from different parts of Uganda.Item Factors influencing households participation in the Savings and Credit Cooperative (SACCO) programmes in Uganda(African Journal of Agricultural Research, 2013) Mpiira, S.; Kiiza, B.; Katungi, E.; Staver, C.; Tabuti, J. S.; Kyotalimye, M.; Muwumba, P.; Karamura, E.; Tushemereirwe, W. K.Uganda Cooperative Alliance established SACCO’s as a response to Governments call to provide affordable financial services to rural poor. Over the year’s membership and share capital grew. This study investigated factors influencing household’s participation in SACCO programmes. Participants were disaggregated into savers and none savers. Degree of participation was estimated, an ordered probit function was used to establish likelihood of participation. Member’s participation increased with growth in incomes, dependants in secondary schools. Earning salary, rent, salaried spouse were less likely to participate. Increase in distance from the household to SACCO reduced household’s participation due to increased transaction costs.