Evaluation of a lateral flow device for in-field detection of Banana Xanthomonas Wilt and its application in tracking the systemicity of Xanthomonas campestris pv. musacearum

Early detection of Banana Xanthomonas Wilt (BXW) in the field and immediate destruction of infected plants or plant tissue are key control methods to prevent the introduction and spread of BXW. This requires rapid, cost effective and an on-site diagnostic tool to detect the bacterium, Xanthomonas campestris pv musacearum (Xcm). Polymerase chain reaction (PCR) detection technique for BXW is efficient but requires expensive equipment and knowledgeable expertise; this limits PCR application to the laboratory. This study therefore was carried out to evaluate the enzyme - linked immunosorbent assay (ELISA) tool configured as a lateral flow device (LFD) for detection of Xcm. Studies on the systemicity of Xcm in banana were carried out using the BXW - LFD in a field trial of 300 banana plants of Pisang Awak inoculated with the Xcm at Kiifu Forest, Mukono District, Uganda. Pseudo-stem samples from symptomatic and asymptomatic suckers were collected and tested with the LFD and the results compared with conventional PCR using the GspDm BXW primers. The LFD was able to detect Xcm3

In-vitro proliferation of Musa balbisiana improves with increased vitamin concentration and dark culturing

Musa balbisiana is a wild banana genotype with important traits such as drought tolerance and disease resistance. Uniform and clean plants are often required to study these traits in different laboratories but plants can only be generated through a tissue culture process yet for a long time a protocol for regeneration of the same has not been available. Here, we demonstrate that modification of the anti-oxidant content of the in- vitro plant proliferation medium through adjusting the concentration of ascorbic acid and thiamine HCl in the basal MS medium together with subjecting the explants to dark culturing conditions improved proliferation of M. balbsiana by over 10 fold. These treatments resulted in 40 shoots per initial explant material at the best performance

Bringing research results to users: the case for a knowledge resource centre

Poster presented at Scientific and Technical Information and Rural Development: Highlights of Innovative Practices. 13. IAALD World Congress. Montpellier (France), 26-29 Apr 201

Community mobilization: a key to effective control of banana Xanthomonas wilt

Banana xanthomonas wilt (BXW) remains a major threat to banana, an important food and income crop for 12 million poor small-holder farmers in Uganda. Although, BXW has been controlled to some extent in parts of South-western Uganda, it is still a big problem in banana growing areas of Central and Eastern Uganda. We hypothesized that differential success in BXW control is mainly due to approaches used in the BXW control. This paper therefore, evaluates stakeholder mobilization approaches used in promoting technologies for BXW control in Uganda between 2006 and 2009. Results showed that farmer field schools host communities had more farmers (33%) that had low or no BXW infection (<10 infected plants) as compared to smaller proportions (23.5%) of farmers from communities that were using community action or that were mobilised using the traditional approach (22.9%) to control BXW. There was higher BXW prevalence in communities that were using community action (68.8%) or were mobilised traditionally (66.3%) than in those that hosted farmer field schools (43.4%). Consequently, there was higher (53%) banana production recovery on farms that hosted farmer field schools than those that used other institutional approaches (22%). BXW was better controlled by farmers mobilised using farmers field schools than those mobilized through community or traditional approaches

Ploidy level of the banana (Musa spp.) accessions at the germplasm collection centre for the East and Central Africa

Banana germplasm collections serves as a source of useful genes for banana breeding. However, insufficient and/or inaccurate information on the ploidy level of the germplasm renders its utilization in breeding difficult. The objective of this study was to determine and validate the ploidy level of 120 banana accessions in the ex situ germplasm collection centre for the East and Central Africa, located in Mbarara, Uganda. Flow cytometric analysis of the nuclear DNA content was used to determine the ploidy level of the accessions. Results indicate that accessions: Bura, Diana, Kambani-Rungwe, Paji and Pagatau, and Rungwe that were previously classified as diploids are actually triploids, whereas Selangor previously known to be a diploid is a tetraploid. Accessions such as Galeo, Mwitupemba and Ntindi 1 that were previously classified as triploids were found diploids. GT, FHIA 25 and Muzungu Mwekundu that were considered as tetraploids, were found triploids. The information generated will guide correct placement of these accessions in the regional germplasm collection centre for the East and Central Africa and their utilization in banana breeding

Modeling the dynamics of banana Xanthomonas wilt transmission incorporating infectious force in both asymptomatic and symptomatic stages

Despite massive efforts by regional governments and partners in the East and Central African region towards fighting Xanthomonas Wilt of banana, the disease is reported to continue to spread to new areas and resurge in others it had been contained. The use of asymptomatic but infectious plants is hypothesized to play a leading role in the persistence of the disease and it's introduction to new areas. A model for the transmission of BXW by symptomless plants is proposed and analyzed. It incorporates both horizontal and vertical transmission modes and a dual source of inoculum in the force of infection. The basic reproduction number, R0, is obtained and it is found to completely determine the global dynamics of the model. By construction of a suitable Lyapunov function for the second additive compound system, the global stability of the endemic equilibrium is established. Numerical simulation and sensitivity analysis of the basic reproduction number indicate that the disease is mainly driven by parameters involving asymptomatic plants rather than symptomatic ones

Farmers' awareness and application of banana Xanthomonas wilt control options: The case of Uganda and Kenya

Banana is a key staple and cash crop in east and central Africa. However, the recent outbreak of Banana Xanthomonas wilt (BXW) has threatened farmers whose livelihoods depend on the crop. Since 2002, stakeholders embarked on campaigns to sensitize farmers on the disease and its management. This study evaluated the effectiveness of these efforts by examining farmers' awareness of the disease, control options and their application in Uganda and Kenya. Data on BXW distribution and incidence, farmers' awareness of symptoms, mechanisms of spread and control options of the disease and banana production were collected through household surveys conducted in 2010. The results indicated that most farmers (> 90%) were aware of the disease and its symptoms and more than 50% were aware of the recommended control measures. Farmers obtained information on the disease from multiple sources but farmer-to-farmer interaction was the main source suggesting the key role rural social networks play in managing the disease. Not all affected farmers were able to apply control measures due to cost of intervention, lack of labour and inputs. The study recommends strengthening of linkages among stakeholders for better coordination of efforts and participatory development and promotion of farmer-oriented interventions that address farmer constraints

Selection of cooking banana genotypes for yield and black Sigatoka resistance in different locations in Uganda

It is imperative to systematically evaluate new banana genotypes in different locations before national release. This enables selection and recommendation of superior genotypes as new varieties for a wider range of environments. The objective of the present study was to select banana genotypes with stable and high performance for bunch yield and leaf black Sigatoka resistance. Eleven cooking banana genotypes developed by the Uganda National Agricultural Research Organization in collaboration with Bioversity International, and two check varieties were evaluated in multi-location preliminary yield trials in Uganda. Data collected were analyzed using Additive Main Effects and Multiplicative Interaction (AMMI) model, AMMI Stability Value, and Genotype Selection Index (GSI). Genotype × location interaction was significant for all the traits assessed. Most of the new genotypes had low interaction effects with locations for bunch yield (69.2%) and black Sigatoka (92.3%). The most stable genotypes for bunch yield were NABIO815, NABIO1117, NABIO216 and NABIO306 whereas for black Sigatoka resistance, were NABIO1011, NABIO815, NABIO1009 and NABIO216. Using the GSI that defines the most desirable genotypes as those that combine high agronomic performance and stability across environments, four genotypes (NABIO306, NABIO1011, NABIO808 and NABIO1009) were selected. These genotypes, in addition to their high performance for agronomic traits and stability, had soft and yellow fruit pulp on cooking, and will be advanced on farm for further evaluatio

An analysis of the risk from Xanthomonas campestris pv. musacearum to banana cultivation in Eastern, Central and Southern Africa.

Xanthomonas wilt, which is commonly known in East Africa as banana Xanthomonas wilt (BXW), banana bacterial wilt or enset wilt, is a devastating disease caused by the bacterium Xanthomonas campestris pv. musacearum. It was first reported in 1968 in Ethiopia, where it remained confined until it was observed in Uganda in 2001. The subsequent spread of the bacterium throughout the Great Lakes region, where banana forms a large proportion of the diet, is posing a serious threat to food security. The authors, scientists from the Central Science Laboratory in the UK and Bioversity International in Uganda, discuss the distribution and epidemiology of the causal agent and the measures farmers can use to protect their plants from contracting this deadly disease. They also analyse the impact of the measures deployed to date and make recommendations to reduce the risk of the disease spreading to other countries