Effect of the fungus of <i>Ramularia tulasnei Sacc</i> on chlorophyll fluorescence in garden strawberry

Abstract

The relevance of early undamaging diagnosis of fungal diseases of garden strawberry has been proved. Comparative analysis of the main methods of early diagnostics of cultivated plants has been carried out. Fresh leaves of common garden strawberry of Symphony and Eliani cultivars grown in natural conditions in pots on bio-testing ground were used for research. Soil composition was leached chernozem with the addition of peat and fertilizer complex (superphosphate and potassium salt). Informative parameters of chlorophyll fluorescence of plant tissues of strawberry leaves obtained as a result of the impact of a bio-stressor (fungus of Ramularia tulasnei Sacc.) have been studied. Parameters of chlorophyll fluorescence in garden strawberry leaves were measured by the Dual-PAM-100 fluorimeter device in accordance with the technique developed. Fluorimeter mode control was exercised by means of the computer with the Windows operating system according to the special program. As a result of pilot studies, it was revealed that for two cultivars of garden strawberry Symphony and Eliani, fungus of Ramularia tulasnei Sacc caused the most significant and stable changes of chlorophyll fluorescence parameters of plant tissues of leaves: quantum yield of photochemical transformation of light energy, the minimum chlorophyll fluorescence a in the objects adapted to light and quantum yield of non-regulated energy dissipation. When strawberry cultivars Symphony and Eliani were affected by this bio-stressor, the parameter of quantum yield of non-regulated energy dissipation showed the most identical properties on the nature of its dependence and current values. Credible early undamaging diagnosis of fungal diseases of garden strawberry was proved possible by the level of quantum yield of non-regulated energy dissipation.