Kalinina, RP Novoivanovskoe, Odintsovo Region, Moscow Province, 143026 Russia; 3Agrophysical Research Institute, Federal Agency of Scientific Organizations, 14, Grazhdanskii prosp., St. Petersburg, 195220 Russia; 4Federal Research Center the N.I. Vavilov All-Russian Institute of Plant Genetic Resources, Federal Agency of Scientific Organizations, 42-44, ul. <...> Bol’shaya Morskaya, St. Petersburg, 190000 Russia, e-mail yu.chesnokov@vir.nw.ru Acknowledgements: We are grateful to Dr. N.V. Kocherina for help with the statistical calculations of heterozygosity and its dispersion. <...> Received March 25, 2016 A b s t r a c t Esterases represent a large group of enzymes that catalyze cleavage of multiple-ester bonds. <...> In general, they are divided into four types: cholinesterases (most frequently, these are identified using ordinary electrophoretic analysis), acetylesterases, arylesterases and carboxyl esterases. <...> Plant carboxyl esterases catalyze conversion of the esters into bioactive acids and alcohols, thereby playing a key role in many biological processes. <...> Lack of epistatic interactions as well as a co-dominant nature of the inheritance of the esterase isozymes makes them meaningful for quick and accessible investigation of the processes of biochemical adaptation to environmental changes. <...> Such a type of markers, which is convenient for solution of practical problems of selection, can be used as a tool that can speed up and simplify the selection of the significant material. <...> The aim of this study was to estimate the isoenzyme profile of esterases isolated from mature seeds, and to ascertain, using such a biochemical marker, the polymorphism among samples of promising breeding material of the hexaploid wheat (Triticum aestivum L.). <...> Ripe seeds from following wheat cultivars were used as samples: Zlata, Lyubava, Agatha, Lisa (spring wheat) and Mera (winter wheat) (originated by Moscow Agricultural Research Institute «Nemchinovka», Moscow Province); lines AFI91 and AFI177 (spring wheat) and recombinant inbred lines of the mapping populations ITMI — 7, 10, 29, 32, 44, 47, 57, 83, 88, 89, and 115 (spring wheat) (originated by Agrophysical Research Institute — AFI, St. Petersburg). <...> The seeds were ground in a porcelain mortar and the flour was sieved. <...> The enzymes were extracted from the flour <...>