Effet protecteur du silicium sur la tolérance du bananier à deux maladies fongiques
(2012)
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- Abstract
- (en) Silicon is known to reduce the incidence of various pathogens on many plants. Banana is a Si-accumulator monocot plant. There is little information, however, about the potential positive effects of Si on the resistance of banana to plant pathogens. The objective of this PhD thesis was to determine the effects of Si supply on fungal infection on banana (Musa acuminata cv. Grande Naine). Experiments were conducted under controlled conditions in order to test the susceptibility of banana amended, or not, with Si to a root-rot fungus, Cylindroladium spathiphylli, and to a foliar pathogen, Mycosphaerella fijiensis. In the experiments, the Si supply led to an increase in the Si concentration in banana leaves, reaching values of 1% to 3%. Banana plants amended with 2mM Si on a ferralsol, exhibited a reduction of about 50% in the necrosis percentage of C. spathiphylli inoculated roots, 14 days after inoculation, compared with plants grown in the absence of Si. The Si amendment has a positive effect on plants affected by C. spathiphylli. The protective role of Si in the banana-M. fijiensis pathosystem was also highlighted in this work. The addition of Si to the nutrient solution supplied to plants resulted in a reduction and a delay of the disease progress. Biochemical analysis of leaf extracts of banana plants amended with Si and inoculated with M. fijiensis revealed a slightly higher concentration of total polyphenols and an increasing of the antioxidant activity compared to extracts from plants not amended with Si. These results suggest a relationship between the silicon supply, the total polyphenols content and antioxidant activity. The availability of silicon for banana plants was assessed in a sand-peat substrate amended with commercial wollastonite. The Si leaf concentrations increased with increasing rate of wollastonite amendment but remained relatively low in comparison with previous reports. These results show that calcium silicate with high rate could be a source of available silicon for banana in field conditions. The positive effect of a Si supply on banana resistance to biotic stresses was demonstrated in this work. This suggests that Si could provide an environmentally friendly alternative to pesticides for the integrated control of important crop diseases.
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Citations
Kablan, A. L. (2012). Effet protecteur du silicium sur la tolérance du bananier à deux maladies fongiques. https://hdl.handle.net/2078.5/89938