AMARI, E. G. D. L. Université de Cocody-Abidjan - Laboratoire de Physiologie Végétale, UFR Biosciences, Côte d’Ivoire , DICK, E. Université de Cocody-Abidjan - Laboratoire de Physiologie Végétale, UFR Biosciences, Côte d’Ivoire , KONE, D. Université de Cocody Abidjan - Laboratoire de Physiologie Végétale, UFR Biosciences, Côte d’Ivoire , ABO, K. Institut National Polytechnique Félix Houphouët-Boigny (INP-HB) - Laboratoire de Phytopathologie et de Biologie Végétale, Côte d’Ivoire , KOBENAN, K. Centre National de Recherche Agronomique (CNRA), Station de Recherche de Bimbresso - Laboratoire de Phytopathologie, Côte d’Ivoire

RESPONSE TO JUGLONE TOXIC EFFECT IN VARIOUS GENOTYPES OF BANANA (MUSA AA, AAA, AAB, AAAA, AAAB)

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In Côte d Ivoire, Black Sigatoka, caused by Mycosphaerella fijiensis Morelet, is a major constraint in banana plantain production. The use of juglone, a purified toxin of this pathogen, could constitute an alternative in the early selection of new banana genotypes resistant to Black Leaf Streak Disease (BLSD). Local cultivars and hybrids to be vulgarized, were evaluated in order to elucidate the variability of banana varieties and to assess the possibility of using juglone to breed for resistance to BLSD. Necrosis induction bioassays, electrolyte leakage, combined with phenolic compound quantifications were performed on both diploid and triploid reference cultivars, as well as tetraploid hybrids following juglone infiltration. Results show, based on minimal concentrations and intensities of necrosis, that genotypes sensitivity to juglone was generally related to susceptibility to the disease in the field. The tetraploid genotypes exhibited the lowest necrosis intensities when juglone concentration was less than 100 ppm. Forty eight hours after treatment, phenols content of FHIA23 and PITA14 hybrids was at a basal level. These tetraploid banana probably produced antioxidants with high affinity for the active oxygen species (AOS) inducing their tolerance to the disease. This study confirms the use of juglone for simple and rapid screening of banana varieties with resistance to BLSD. Pathological and physiological parameters related to biochemical evaluation, constitute the best strategy for identifying genotype with the greatest resistance to Mycosphaerella fijiensis. However, this great resistance is not systematically related to a higher content in total phenols.

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Differential reaction , juglone , black leaf streak disease , phenolic compounds

Agronomie Africaine

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