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Improving Banana for Resistance Against Xanthomonaswilt in Sub Project Progress Report 2012 Improving Banana for Resistance against Xanthomonas Wilt in Sub-Saharan Africa Message from the The Banana Xanthomonas Wilt provide a cost-effective method (BXW) pathogen, the cause of to develop varieties resistant to Project Coordinator this phenomenon, costs banana BXW. farmers millions of dollars in damages every year across The novel green pepper proteins East and Central Africa. The that give crops enhanced pathogen infects all varieties, resistance against deadly including East African Highland pathogens can also provide Banana and the exotic types. The effective control against other rapid spread of the disease has BXW-like bacterial diseases in endangered the livelihoods of other parts of the world. The millions of farmers who rely on mechanism of this resistance is banana for staple food and cash. such that it rapidly kills plant cells at the region of attempted There are presently no invasion by the pathogen and commercial chemicals, bio- forms a physical barrier to control agents or resistant prevent further infection. In varieties that could control the addition, it also activates the ananas are among the spread of BXW. Even if a source defences of surrounding and most important food of resistance is identified soon, even distant uninfected parts crops after maize, rice, developing a truly resistant of banana plants leading to a wheat, and cassava. banana through conventional systemic acquired resistance. BAnnual production in the world breeding would be quite difficult is estimated at 130 million and would take years, given the The transgenic approach brings tonnes, nearly one-third of it sterile nature and long gestation in more options of defence being grown in Sub-Saharan period of the crop. against the wilt but more Africa (SSA), where the crop significantly, it presents real provides more than 25 percent Transgenic technologies that optimism of saving livelihoods of the food energy requirements facilitate the transfer of useful in Africa. for over 100 million people. East genes across species have Africa produces and consumes been shown to offer numerous Dr Jacob H Mignouna the most bananas in Africa, advantages to avoid the natural Project Coordinator with Uganda being the world’s delays and problems in breeding second largest producer after bananas. These technologies India. Banana farmers especially in Uganda are currently battling with the anguish of watching their fruit ripen prematurely, seeing their leaves wilt and then witness the inevitable death of the entire plant. Progress Report 2012 Bacterial Wilt-Resistant Banana Project [ 1 ] Background ananas and plantains are an important food source for over 100 million people in SSA. In the east African highlands and most of the Great Lakes region, bananas are a major Bstaple food and a source of income for over 50 million smallholder farmers. East Africa produces about 20 percent of the world output. However, many living and non-living factors greatly reduce productivity for banana cultivated under traditional African farming systems. For instance, as a result of the BXW banana disease, a 50 percent decline in household incomes from banana sales and a corresponding increase in banana prices were observed during 2001 and 2004 in Uganda. Other costs associated with BXW include A banana bacterial wilt infected plant – the labour for cutting down and disposing of infected spread of the disease has affected the livelihood plants, de-budding the male flowers and disinfecting of thousands of farmers who rely on the crop as cutting tools. These cultural disease control methods staple food and for income generation currently in use have been useful in confining the spread of the disease and the on-going work to of Congo, Rwanda, Tanzania and Kenya. Its rapid develop disease resistant material will enhance what spread has endangered the livelihoods of thousands has been achieved so far. of farmers who rely on banana as a staple food and for income generation. The disease is very The BXW disease caused by Xanthomonas campestris destructive, infecting all banana varieties. Prospects pv. Musacearum, was first reported about 44 years of developing varieties with resistance to bacterial ago in Ethiopia on Ensete (a native plant to Ethiopia) wilt through conventional breeding are limited, which is closely related to banana and then it was as no source of germplasm exhibiting resistance also discovered on banana. Outside of Ethiopia, against BXW has been identified. Transgenic BXW was first identified in Uganda in 2001 and technologies for banana may provide a timely subsequently reported in the Democratic Republic alternative solution to the BXW pandemic. Project overview he plant ferredoxin-like protein (pflp)gene and the hypersensitivity response assisting protein (hrap) gene isolated from sweet pepper by Dr Teng-Yung Feng of Academia Sinica in Taiwan has been identified as a possible Tsolution for developing a transgenic banana resistant to BXW. AATF brokered access to this gene from Academia Sinica and is working with partners - the International Institute of Tropical Agriculture (IITA) and the National Agricultural Research Organisation (NARO) in Uganda - to develop a Xanthomonas wilt- resistant banana from East African preferred germplasm. The outputs expected from the project include proof that either the hrap or pflp gene confers resistance to BXW and the development and testing of transgenic lines with hrap and pflp genes. It is also expected that there will be additional cultivars of banana/plantain transformed in Uganda and Kenya. Smallholder farmers in Sub-Saharan Africa It is expected that smallholder farmers in SSA will have access are expected to have access to the adapted high yielding bananas with resistance to to adapted high yielding bananas from east African highland Xanthomonas wilt disease by 2017 germplasm with resistance to BXW by around 2017. [ 2 ] Bacterial Wilt-Resistant Banana Project Progress Report 2012 Project management uring the reporting period, AATF filed an application for the patent registration of Dthe new pflpgene at the African Regional Intellectual Property Organisation office to protect the new pflpgene in Uganda and Partners who attended the review Kenya. and planning meeting in July 2012 visiting the confined field trial site A project review and planning in Kawanda, Uganda meeting was held in July 2012 to take stock of progress the banana cultivar Sukali ndiizi meeting was also attended by and redefine roles and popularly known as apple banana participants drawn from various responsibilities of partners in that have shown resistance to the research institutes involved project implementation. During disease. The lines are undergoing in banana research in Kenya, the meeting, scientists working testing under confined field Tanzania, Rwanda, Burundi and on the project reported that they trials (CFTs) at the Kawanda Uganda. have generated several lines of research station in Uganda. The Product development progress ixty-five transgenic plants and non-transgenic mother plants have been evaluated for BXW Sresistance in CFTs in Uganda and assessed for disease symptom development. All transgenic lines tested have significantly higher (P≤0.05) resistance in comparison to control non- transgenic plants. However, 12 The confined field trial site in lines (7 lines with Hrap gene Uganda where both transgenic and non-transgenic mother plants were and 5 lines with Pflp gene) have evaluated for banana bacterial wilt shown resistance to BXW and resistance are being evaluated for second ratoon plants. The mother plants resulted in enhanced resistance Also more than 100 transgenic were harvested in December to Xanthomonas wilt. More lines of Sukali Ndiizi and 200 2011. The bunch weight and size transgenic lines with additional lines of Gonja manjaya with of transgenic lines are similar to farmer preferred cultivars will stacked Hrap and Pflp have been non-transgenic plants. The best be generated by IITA at the generated and validated by PCR. 10 lines will be tested further Biosciences east and central Three replicates of about 150 with more replicates in a second Africa (BecA) hub in Kenya. transgenic lines with stacked trial through the support of genes were evaluated for BXW the United States Agency for About 300 transgenic plantlets of resistance by artificial inoculation International Development’s plantain cultivar Gonja manjaya of potted plants in screen house. Agricultural Biotechnology were obtained and validated More than 30 lines with stacked Support Programme. for presence of transgene by genes showed resistance. polymerase chain reaction Evaluation of additional lines is Results from the trials (PCR) analysis. These lines are on-going and disease indexing demonstrated that constitutive now under multiplication for of plants with stacked and single expression of the sweet pepper evaluation for disease resistance genes will be used to calculate Hrap or Pflp gene in banana under glasshouse. significant differences. Progress Report 2012 Bacterial Wilt-Resistant Banana Project [ 3 ] Confined field trial compliance nvestigations on the efficacy of transgenic banana have continued at NARO in Uganda since October 2010 Iin compliance with requirements pertinent for transgenic plants under confined field conditions. A compliance audit mission carried out by AATF at the CFT site in July 2012 did not reveal any incidences of compliance infraction. In addition, a CFT Some of the partners during the CFT compliance
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