Effect of some growth regulators on chlorophyll fluorescence in Viola × wittrockiana ‘Wesel Ice’

Anotacija

The objective of this study was to determine the influence of daminozide, paclobutrazol and daminozide in combination with CCC on chlorophyll fluorescence and morphological characteristics in Viola × wittrockiana ‘Wesel Ice’. Chlorophyll fluorescence was measured on the abaxial side of the leaves three weeks after treatment. Measurements of chlorophyll fluorescence were done using a fluorescence monitoring system (Model FMS-1, Hansatech, Kings Lynn, UK). Before measurements, the leaves were dark-adapted for 30 min. The parameters of maximal fluorescence (Fm), variable fluorescence (Fv) and Fv / Fm ratio under the influence of growth regulators increased by 1.6–8.3%, 4.7–10.6% and 2.4–3.9%, respectively. PBZ had the strongest retarding effect in all aspects, while B9 + CCC proved to be the least effective. At the concentrations used, PGR did not provide control of plant and flower diameter and significant differences in the number of flowers. There was a significant reduction in fresh weight (0.05–0.20 g) and area (0.6–2.8 cm2) of leaves. PGR significantly increased total foliar chlorophyll (33.7–55.4 mg, 100 g–1 25.6–42.0%) and carotenoid (15.3–28.2 mg 100 g–1, 29.9–55.3%) concentration. Chlorophyll fluorescence parameters showed that photochemical activity was greater in leaves of the treated plants. Keywords: chlorophyll fluorescence, growth regulators, pigments, Viola × wittrockiana