International Journal of Horticultural Science (Aug 2004)
Effect of Erwinia amylovora infection on peroxidase enzyme activity in resistant apple cultivars
Abstract
Two apple cultivars that display enhanced resistance to fire blight (causal agent: Erwinia amylovora) were selected. The aim of the present study was to characterize the peroxidase (POD) enzyme activity of `Szemes alma' (a historical cultivar) and MR-03, (a Hungarian multiresistant hybrid of 'Prima') and compare them to susceptible 'Jonathan M 40' and resistant 'Remo' controls. Peroxides enzyme activity during E. amylovora infections was investigated in artificially infected apple shoots. Increases in enzyme activities were observed in a `Jonathan M40' and in 'Remo', MR-03, `Szemes alma' cultivars. There was a consistent relationship between total enzyme activity and fire blight disease severity. High activity of the peroxidase was positively correlated with the degree of resistance to fire blight. A general hypothesis that POD activity is related to fire blight susceptibility/resistance is supported by our results.
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