COMPARISON OF PHOTOSYNTHETIC PARAMETERS IN DIFFERENT WHEAT (TRITICUM AESTIVUM L.) VARIETIES

Dynamics of photosynthesis pigments in the leaves of different varieties of winter wheat during the vegetation period is analyzed in the paper. The accumulation of pigments in the plant depends on the physiological activity, growth and development of the plant, therefore the composition and content of photosynthesis pigments chlorophyll a, b and carotenoids reflect the general condition of the plant. The ratio of chlorophyll a / b for normal photosynthesis activity in the leaves of the plant should be at least 1:3. The object of the research is different varieties of winter wheat (Triticum aestivum L.) - 'Artist', 'Edvin', 'Skagen', 'Bertold' and 'Viola'. Field experiment was carried out at the Experimental Station of Aleksandras Stulginskis University in 2015-2016. Soil type was identified as IDg8 - k (LVg - p - w - cc) - shallow calcareous luvisol (Calc (ar) i - Epihypogleyic Luvisols). Agrochemical parameters of the soil were determined using accepted analytical methods. The content of photosynthesis pigments (chlorophyll a, b and carotenoids) in green leaf mass was determined in 96% ethyl alcohol extract applying spectrophotometric Wettstein method, "Genesys" 6 spectrophotometer. The photosynthesis productivity (Fpr) was calculated according to the formula: Fpr = 2 (M2-M1) / (L1 + L2) T. The accuracy of the data analysis was estimated according to the standard measurement deviation from the mean. The highest content of photosynthesis pigments has been accumulated by winter wheat variety 'Skagen'. The best result has been observed at the end of nodding stage. A lower content of photosynthesis pigments has been found in the leaves of 'Edvin', 'Viola' and 'Artist' varieties. The highest photosynthesis productivity of all winter wheat varieties has been recorded at the end of nodding stage, and decrease of photosynthesis productivity has been observed since milk maturity stage.