ISHS Acta Horticulturae 588: II International Symposium on Cucurbits
CHLOROPHYLL FLUORESCENE IN CUCUMBER COTYLEDONS INOCULATED BY CUCUMBER POWDERY MILDEWS (ERYSIPHE CICHORACEARUM AND SPHAEROTHECA FULIGINEA) |
| Authors: | M. Spundová, R. Útratová, J. Naus, A. Lebeda |
| Keywords: | cotyledon senescence |
| Abstract:
Effects of two biotrophic cucumber powdery mildews, Erysiphe cichoracearum and Sphaerotheca fuliginea, on photosynthetic pigment content and chlorophyll (Chl) fluorescence parameters were studied in cucumber cotyledons (Cucumis sativus cv. Marketer) within 35 days after inoculation. No marked changes in the followed parameters were found in case of E. cichoracearum so that this infection had no pronounced effect on the thylakoid function. A decrease in FV/FM, slowing down of the induction kinetics of fluorescence quenching coefficients qP and qN, and a slower recovery of FV/FP after photoinhibitory treatment were observed in case of S. fuliginea. The Chl and carotenoid content per leaf area, Chl a/b and Chl (a+b)/Car (x+c) ratios were slightly lower in these cotyledons. The results indicated that the infection by S. fuliginea caused an acceleration of cotyledon senescence including a decrease in function of photosystem II, an inhibition of electron and proton transfer processes, and a slower regeneration from photoinhibition. | |
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