INFLUENCE OF ZINC NUTRITION ON FUSARIUM WILT OF BANANA - AN ELECTRON MICROSCOPIC INVESTIGATION
A research project between workers in Tenerife and Berlin was undertaken to evaluate the effect of Zn nutrition on fusarium wilt caused by Fusarium oxysporum f. sp. cubense, race 4 (FOC-4) using the banana cultivars ‘Dwarf Cavendish’ and ‘Grande Naine’. The Spanish partner obtained a significant decrease of severity and incidence of fusarium wilt by foliar IAA-spray. There was a tendency that the increase of resistance was more pronounced at Zn supply compared with Zn deficient conditions. In order to find out whether defence mechanisms such as tylose formation in the banana roots are influenced by Zn nutrition, the German group investigated the effects of varied Zn nutrition, using light and electron microscopy. However, tylose formation was not detected. Events of the primary determinative phase of fungus colonization were observed including responses such as retraction of the plant plasma membrane, penetration of the fungus through plant cell walls and formation of protective layers in form of callose-like deposits. These ultrastructural responses to fusarium infection were independent of Zn nutrition. Zn-deficiency was observed to change the ultrastructure of both chloroplasts and mitochondria in the leaves. This may explain that fusarium wilt appeared to be more severe under Zn deficient conditions.
Hecht-Buchholz, Ch., Borges-Pérez, A., Fernández Falcón, M. and Borges, A.A. (1998). INFLUENCE OF ZINC NUTRITION ON FUSARIUM WILT OF BANANA - AN ELECTRON MICROSCOPIC INVESTIGATION. Acta Hortic. 490, 277-284
‘Dwarf Cavendish’, ‘Grande Naine’, defence mechanism, Fusarium oxysporum f. sp. cubense, race 4 (FOC-4), Musa acuminata