Pigments, efficiency of photosynthesis and winter wheat productivity

Abstract

Purpose. To analyze characteristics of pigment apparatus and photosynthetic efficiency of wheat in connection with the perspectives to increase yielding capacity. Methods. Field, small-plot, morphometric, spectrophotometric, high-performance liquid chromatography, statistical ones. Results. The results of comparative studies of the photosynthetic apparatus characteristics of two winter wheat varieties at different levels of its organization (chloroplast, leaf, and crop), with more than 40 years difference of breeding time, are presented. It was shown that under different growing conditions the modern variety ‘Favorytka’ differed both by higher content of chlorophyll as the main photosynthetic pigment and its gross amount in the leaves, as well as specific leaves weight and longer functioning of crop photosynthetic apparatus at the late stages of vegetation than old variety ‘Myronivska 808’. Based on the changes of the de-epoxidation state of xanthophyll cycle pigments, caused by variation of light conditions, the better photosynthetic apparatus efficiency of variety ‘Favorytka’ was established. All these changes ultimately contributed to more efficient use of absorbed light energy for biomass formation of this variety. Found on the analysis of the own data and literature, it is shown that increasing the efficiency of photosynthesis is a promising strategy for rai­sing plant productivity. Conclutions. It was found that the increase of yield of modern winter wheat variety ‘Favorytka’, as compared with variety ‘Myronivska 808’ to be bred in the 60s, was accompanied with a rise of content and gross amount of chlorophyll and a prolongation of functioning of crop photosynthetic apparatus during the reproductive period. In addition, the modern variety was characterized by an increase in photosynthetic productivity due to more efficient use of absorbed light energy.