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
Dubois, T. Coyne, D.
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: t.dubois@cgiar.org
This Technical Innovation
Brief is published by:
SP-IPM Secretariat
SP-IPM@cgiar.org
www.spipm.cgiar.org
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
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. 397-
409.
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)