Techniicall Techn ca Innovatiion Briief Innovat on Br ef
No. 10, February 2011
Enhanced protection for tissue cultured banana T. Dubois, D. Coyne, A. zum Felde plants
Banana About one-third of the global banana production comes from sub-Saharan Africa, especially the Great Lakes region of East Africa, where millions of subsistence farmers and consumers depend on the crop as a staple food. Dessert banana production is a multi-million dollar industry in Latin America, which produces over 70% of global banana exports. The world over, banana is traditionally propagated by means of field-obtained suckers or side-shoots, which are often contaminated with soil-borne diseases and pests, such as nematodes (Radopholus similis, Pratylenchus goodeyi, P. coffeae, Helicotylenchus multicinctus. Meloidogyne spp.) and banana weevils (Cosmopolites sordidus). With the exception of fastidious bacteria and viruses, normally eliminated at the stock nurseries, tissue cultured (TC) plants provide a source of pest- and disease-free planting material. TC plants also have the benefits of uniformity, enabling better planning for markets and more rapid recovery from broad-scale damage, such as that from hurricanes. In Africa, a number of commercial enterprises are now beginning to supply farmers with TC plants, while in Latin America, TC plants are used almost exclusively to renovate aged commercial farms Banana corm damaged by tunnelling larvae of the banana weevil (left); toppled and establish new ones. banana plants due to nematode infestation (right). – D. Coyne However, following their transfer to the field, TC plantlets tend to be less robust than suckers and require greater care and attention. As a consequence of their aseptic and sterile production, TC plants are devoid of the beneficial microorganisms present in suckers and have an untested defense mechanism. They are nevertheless regularly planted into fields with high pest and disease burdens and abiotic constraints. Endophytes Endophyte is a ubiquitous term for microorganisms that naturally occur in planta with neutral, positive, or negative impact to the host (Backman & Sikora 2008). Some endophytes have proved beneficial by enhancing plant growth and by providing host protection from pests and diseases (Sikora et al. 2008). The many strains of Fusarium oxysporum are the most common endophytes in banana roots. Reintroducing beneficial endophytes during the TC production process, to enhance the plant’s natural defense system has proved viable and beneficial (Dubois et al. 2006a; zum Felde et al. 2009).
Healthy banana seedlings from commercial tissue culture. – A. zum Felde
CGIAR Systemwide Program on Integrated Pest Management (SP-IPM) is a global partnership that draws together the diverse IPM research, knowledge and expertise of the international agricultural research centers and their partners to build synergies in research outcomes and impacts, and to respond more effectively to the needs of farmers in developing countries.
SP-IPM Technical Innovation Briefs present, in short, IPM research findings and innovations for the management of pests, diseases, and weeds in agricultural production.
This and other IPM Briefs are available from www.spipm.cgiar.org
Although the endophyte-host-pest association is complex, studies have revealed that certain endophyte strains will activate enzymatic host-plant defense mechanisms following inoculation (Sikora et al. 2007, Paparu et al. 2010). Some enzymes become upregulated only when plants have been further challenged by nematodes, a phenomenon called priming, which is particularly desirable as this enables enhanced plants to conserve energy in the absence of pests. Depending on field conditions and the endophyte strain inoculated, enhanced TC banana plants have outperformed nematicide-treated TC plants, exhibiting less root damage and with 20-50% lower populations of R. similis (zum Felde et al. 2009). Currently, the economic effects of endophyte-enhanced TC banana plants in smallholder farms are being investigated in Uganda, and preliminary results indicate that yields and revenues are greater than those from non-enhanced TC plants.
Fusarium oxysporum-enhanced (left) and
conventional (right) tissue culture banana seedlings of same age. – T. Dubois
About the authors
Banana tissue culture plantlets are drenched in endophyte spore suspension to enhance their defense mechanisms. – A. zum Felde
In banana, TC plants are enhanced with endophytes by drenching the roots of plantlets with a spore suspension; this technique circumvents many of the problems traditionally associated with biological control agents (BCAs) at the farmers’ level and can be readily integrated into commercial TC production (Sikora et al. 2008). Research has also been initiated using known BCAs, such as the entomopathogenic fungi Beauveria bassiana and Trichoderma spp., to act as “artificial endophytes”. These fungi have shown high levels of internal colonization of banana tissues with good potential for managing the banana weevil (Akello et al. 2008).
zum Felde, A.
The authors are members of the IITA research team and specialists in different disciplines of IPM. Thomas Dubois is an entomologist based in Uganda. Danny Coyne is a plant nematologist stationed in Tanzania. Alexandra zum Felde is a PostDoc in Banana and Plantain Agronomy for West Africa and is based in Nigeria. email: email@example.com
Going commercial Releasing endophyte-enhanced TC plants to farmers has created an efficient and novel plant protection option and constitutes a much sought-after alternative to pesticide use in commercial production. At present, F. oxysporum strain V5w2 is being commercially registered in Kenya, under the leadership of Jomo Kenyatta University of Agriculture and Technology (Dubois et al. 2006b). Following registration, the Real IPM Company will be licensed to mass-produce the product for use in banana seed systems. However, as only low doses per plant are needed, concerns have been voiced over profit margins. In Uganda, endophyte technology has therefore been embedded directly in commercial TC companies, such as Agro-Genetic Technologies. References
This Technical Innovation Brief is published by: SP-IPM Secretariat SP-IPM@cgiar.org www.spipm.cgiar.org
Akello, J., Dubois, T., Coyne, D., and Kyamanywa, S. (2008). Effect of endophytic Beauveria bassiana on populations of the banana weevil, Cosmopolites sordidus, and their damage in tissue-cultured banana plants. Entomologia Experimentalis et Applicata 129: 157-165. Backman, P.A. and Sikora, R.A. (2008). Endophytes: An emerging tool for biological control. Biological Control 46: 1–3. Dubois, T., Gold, C.S., Paparu, P., Athman, S., and Kapindu, S. (2006a). Tissue culture and the in vitro environment. Enhancing plants with endophytes: potential for ornamentals? In Teixeira Da Silva J (Ed.). Floriculture, Ornamental and Plant Biotechnology: Advances and Topical Issues. 1st Edition. Global Science Books, London, UK. pp. 397409. Dubois, T., Coyne, D., Kahangi, E., Turoop, L., and Nsubuga, E.W.N. (2006b). Endophyte-enhanced banana tissue culture: an example of public-private partnerships in Kenya and Uganda to transfer technology. African Technology Development Forum 3:18-24. Paparu, P., Dubois, T., Coyne, D., and Viljoen, A. (2010). Effect of Fusarium oxysporum endophyte inoculation on the activities of phenylpropanoid pathway enzymes and Radopholus similis numbers in susceptible and tolerant East African highland bananas. Nematology 12: 469-480. Sikora, R.A., Schäffer, K., and Dababat, A.A. (2007). Modes of action associated with microbially induced in planta suppression of plant-parasitic nematodes Australasian Plant Pathology 36: 124-134. Sikora, R.A., Pocasangre, L., zum Felde, A., Niere, B., Vu, T.T., and Dababat, A.A. (2008). Mutualistic endophytic fungi and in-planta suppressiveness to plant parasitic nematodes. Biological Control 46: 15-23. zum Felde, A., Mendoza, A., Cabrera, J.A., Kurtz, A., Schouten, A., Pocasangre, L., and Sikora, R.A. (2009). The Burrowing Nematode of Bananas: Strategies for Controlling the Uncontrollable. Acta Horticulturae 828: 101-108.
SP-IPM Steering Committee Members: Sikora, R (Program Chair); Nwilene, F (AfricaRice); Ramasamy, S (AVRDC); Staver, C (Bioversity); Buruchara, R (CIAT); Nicol, J (CIMMYT); Kroschel, J (CIP); Yahyaoui, A (ICARDA); Chabi-Olaye, A (icipe); Sharma, H (ICRISAT); Narrod, C (IFPRI); Bandyopadhyay, R (IITA); Heong, KL (IRRI); Bramel, P (DDG –R4D convening center, IITA); Hoeschle-Zeledon, I (Program Coordinator, IITA)
By T. Dubois, D. Coyne, A. zum Felde, Published by CGIAR SP-IPM on 02/01/11
Let us know which of the options below best describes you and we'll direct you to the most relevant content.
Practical Action uses technology to challenge poverty, working with poor women and men around the world.
Explore our work by Country
Explore our work by Technology
+44 (0)1926 634400 firstname.lastname@example.org
© Practical Action