The effect of synthetic inducers of systemic resistance in inhibiting grey mold development on geranium and poinsettia

Abstract

Several chemical activators of resistance were tested to evaluate their efficiency in restricting development caused by <i>Botryotinia fuckeliana (Botrytis cinerea)</i> on geranium and poinsettia leaves. The used signal pathway inducers of salicylic acid, such as DL-â-aminobutyric acid (BABA), g-aminobutyric acid (GABA) and benzothiadiazole (BTH), at the applied rates markedly inhibited the development of grey mould in the both plant species. The mentioned inducers showed no toxic or restricting effect on the fungus growth and development under <i>in vitro</i> conditions. Only methyl jasmonate (Me-JA), a potential activator of independent signal transduction pathway, at the applied quantities (O,1-1,0 mg·ml<sup>-1</sup>), noticeably enhanced the disease spot development probably through stimulation of ethylene synthesis in plant. Me-JA added to medium with <i>B.cinerea</i> showed a strong antifungal action, whereas ethylene significantly stimulated mycelium growth in the <i>in vitro</i> cultures.