关键词: 弱筋小麦, 宁麦9号, 直链淀粉, 支链淀粉, 酶

Abstract: Effects of the ratio between basal N and top dressing N on wheat grain starch formation and its physiological basis were studied. Compared with the treatment of basal N: top dressing N 5:5, the treatment of basal N: top dressing N 7:3, with low accumulation rates of amylose, amylopectin and starch from 7th to 28th and amylose content, was high in the contents of amylopectin and starch at maturity, meanwhile, sucrose phosphate synthase (SPS) activity, sucrose content in flag leaves, and sucrose synthase (SS) activity in grains were low, which could increase sucrose content in grains. At the same time, the activities of AGPP (ADP-glucose pyrophosphorylase), SSS (soluble starch synthase), GBSS (granule bounded starch synthase) were low, therefore, the accumulated starch amount was low. The activities of AGPP, SSS, GBSS were positively correlated to the rates of amylose, amylopectin and total starch accumulating and grain filling, which indicated that these three enzymes played a role in promoting the grain starch accumulation of wheat.

Key words: Weak gluten wheat, Ningmai 9, Amylose, Amylopectin, Enzymes