INFLUENCE OF QUERCETIN, A BIOFLAVONOID, ON THE TOXICITY OF COPPER TO FUSARIUM-CULMORUM

The effect of quercetin on copper toxicity to the mycelial growth of F usarium culmorum was investigated. Increasing concentrations of copper produced dose-dependent inhibition in yeast extract and malt extract agar. However, the toxic level of copper against fungal growth was sig nificantly affected by the concentration of yeast extract in the mediu m, compared to that of malt extract. Apart from the difference in toxi c level of copper, the addition of quercetin antagonized copper toxici ty to hyphae morphology and resulted in the reversal of fungal growth inhibition Quercetin showed a protective ability similar to citrate, a nd was more effective than acetate and proline.