Physiological Effects Of High Temperature And Sucrose & Glutamine Supply On Protein And Starch Formation Of Wheat In Detached Ear Cultured In Vivo

The grain quality formation of wheat is regulated by different wheat varieties, ecological environment and cultural measure. The difference of carbon and nitrogen assimilate accumulation, translocation and distribution in different wheat varieties decided the grain quality formation. Carbon and nitrogen supply, protein formation and starch formation were significantly affected under high temperature. So elucidating the physiological mechanism and regulation principles for grain quality physiology in wheat is of importance for understanding grain quality physiology and guiding cultural management for quality wheat production. In the present study, three glutamine concentrations of 2, 6 and 10g/L and three sucrose concentrations of 10, 40 and 70g/L with two day/night temperature regimes of 32℃/24℃ and 24℃/16℃ from 11 to 14 day after anthesis in Yangmai9 andYumai34 were established, to assess the effects on the formation of grain starch and protein, and further to establish the physiological mechanism and technical approaches for regulation of grain quality in specialty wheat. The main results were summarized as follows:1. The effects of high temperature and glutamine and sucrose supply on single grain weight, starch and protein formation was investigated, and the activities of key enzymes for grain protein accumulation were also studied. The results showed that the contents of total starch, amylose and amylopectin content were markedly reduced with the increasing of glutamine supply, but the contents of protein and its components were enhanced markedly. The activities of glutamine synthetase(GS) and glutamate pyruvic aminotransferase (GPT) in grains were increased by glutamine supply. Glutamine supply enhanced grain amino acid content w, but it had slight effect on grain sucrose content. Contents of total starch, amylose and amylopectin increased with enhancing sucrose supply, while protein and protein components content decreased with increased sucrose supply. Activities of grain glutamine synthetase(GS) and glutamate pyruvic aminotransferase(GPT) both decreased with...