Photosynthetic activity of common buckwheat (Fagopyrum esculentum Moench) exposed to thermal stress

English. The aim of the work was to investigate thermal stress effect on photosynthetic activity of common buckwheat. Seedlings of common buckwheat were exposed to 20°C (control) and 30°C (thermal stress). The research involved the Polish cultivar 'Panda' and strain PA15 and determined kinetics of chlorophyll a fluorescence (Chlf), leaf gas exchange, soluble carbohydrate (SC) content in donor leaves, electrolyte leakage as a parameter of cell membrane permeability, and amount of abscisic acid and jasmonates. In 'Panda' and PA15 plants grown at 30°C, most of Chlf parameters improved. 'Panda' plants grown at 30°C demonstrated a higher increase in net photosynthetic rate, lower transpiration rate, and smaller SC reduction than those of PA15 strain. At this temperature, 'Panda' leaves accumulated greater amounts of jasmonates than that of the control. We concluded that studied genotypes demonstrated disparate responses to thermal stress, but for both, 30°C is more favourable temperature for vegetative growth than 20°C.

English. heat stress; ion leakage; photochemical efficiency; water-use efficiency

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