Association of arbuscular mycorrhizal fungi and Crotalaria spectabilis to control the burrowing nematodes (Radopholus similis) in banana
(2018)
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- Authors
- Supervisors
- Declerck, Stephan
- Abstract
- Banana belongs to the most consumed fruit worldwide. Unfortunately, its production is threatened by numerous pests such as nematodes. Under conventional production systems, nematodes are most often controlled by nematicides. These chemicals may have side effects on human health and the environment, requiring the development of alternatives control measures. Among these are the use of beneficial microorganisms such as arbuscular mycorrhizal fungi (AMF) and push-pull plants such as Crotalaria spp. Here we investigated the combination of AMF with C. spectabilis as control measure against nematodes in banana. Three objectives were pursued in this thesis. First, we studied the effects of AMF on nematodes population and root infestation of banana plantlets grown under autotrophic in vitro culture conditions. Secondly, we investigated the impact of AMF and C. spectabilis together on the control of R. similis population in banana. Finally, we explored the impact of roots exudates of AMF-colonized C. spectabilis plantlets on the movement and vitality of R. similis. Whatever the experiment, all the developmental stages of the nematodes were affected in presence of the AMF. The multiplication rates of the nematodes were drastically decreased, while no effects of the nematodes were noticed on the AMF. C. spectabilis also decreased the nematode population in banana roots, although more slightly. Interestingly, the effects on nematodes were even more pronounced when the AMF and C. spectabilis were considered together. Indeed, the concomitant use of AMF and C. spectabilis impacted all the developmental stages of the nematodes and significantly decreased the surface of necrotic roots as compared to both organisms alone. Concerning the mobility, nematodes were more attracted by exudates of C. spectabilis when opposed to banana exudates suggesting the presence of attractant compounds. The vitality of nematodes was affected by the root exudates of C. spectabilis, while they remained mobile in exudates of banana roots. This effect was highly concentration-dependent and nematodes recovered mobility after cleaning from the C. spectabilis exudates suggesting a nematostatic rather than nematicidal effect of the exudates. The impact of AMF on exudates composition could not be ascertained nor excluded. In conclusion, we confirmed the effects of AMF on the control of nematodes populations and root damage in banana. Their combination with a push pull plant (C. spectabilis) increased even more this effect by reducing drastically the surface of necrotic roots in bananas. Therefore it suggests that the combination of both organisms may be an innovative strategy in integrated pest management, although field trials need to be conducted to confirm this statement. Finally, AMF may possibly modify the exudates of C. spectabilis and thus exert an indirect effect on nematodes, although this needs as well to be demonstrated.
- Affiliations
UCLouvain SST/ELI/ELIM - Applied Microbiology
Citations
Anene, A. (2018). Association of arbuscular mycorrhizal fungi and Crotalaria spectabilis to control the burrowing nematodes (Radopholus similis) in banana. https://hdl.handle.net/2078.5/57731