Effect of drought on distribution of carbon assimilation in different genotypes of spring wheat

Three varieties of spring wheat(Heshangtou,Dingxi24,Longchun8139) was studied by pot-cultivation experiment.The wheat were subjected to two water treatment(normal water supply and drought stress)and were labelled by ~(14)CO_2 ten days before each stage.The radioactivity of different organs at booting stage,flowering stage and grain filling stage(leaves,stems,roots,ear shells) were measured.The result shows that in the process of wheat growth the transporting center of assimilation labelled(by ~(14)CO_2) were altered in different stages,and proper drought treatment can promote the assimilation in root to transport to the above organs and increase the accumulation of assimilation in spike.Compared the three varieties in the normal water treatment the assimilation in the root of new species Longchun8139 is little.The assimilation distributed in the above organ that is good for the growth of spike;under drought stress the assimilation in the root of the old species Heshangtou is very little.