carbohydrate variations of leaf and fruit of nectarine cv. red gold during growth season at gorgan climate

carbohydrate flow between vegetative and reproductive parts of trees is one of the determining factors of yield and fruit quality. therefore, it varies during different times of growth season. the aim of this study was to investigate the carbohydrate content variation during growth season between leaf and fruit of nectarine. so, eight nectarine trees cv. red gold selected randomly in the orchard and after labeling two of them combined and four replications achieved for laboratory tests. results indicated that the highest fresh (9.3 g) and dry (3.3 g) weight of the leaves recorded at the last harvesting stage. fresh to dry weight ratio showed a descending trend than can be indicated this fact that leaf biomass is low at primary harvesting stages and increased gradually. chlorophyll a, b and ab reached to the highest content at the last harvesting stage. total sugar content showed an ascending trend at second and third harvesting stages and decreased at final harvesting stage. fruit chlorophyll content also decreased by maturation and fruit ripening; while, anthocyanin content showed an ascending trend. fruit total sugar content decreased by third stage, two weeks after pit hardening, but increased at the final harvesting stage. sucrose content variations show a higher value at primary stages of fruit growth in comparison with next stages and decreased by final stages. total sugar increased at the fourth stage to third harvesting stage.