氮肥基追比对弱筋小麦宁麦9号籽粒淀粉合成及相关酶活性的影响

Effects of the Ratio Between Basal N and Top Dressing N on Grain Starch Formation in Weak Gluten Wheat Variety Ningmai 9 and Its Enzymes Activities

为研究弱筋小麦籽粒淀粉形成的机制,以弱筋小麦宁麦9号为材料,对不同氮肥基追比对其籽粒淀粉合成及相关酶活性的影响及相关生理基础研究表明,氮肥基追比7∶1∶2处理与5∶1∶4处理相比,花后7～28d籽粒直、支链淀粉及总淀粉积累速率低,成熟籽粒直链淀粉含量低,支链淀粉、总淀粉含量高,剑叶蔗糖磷酸合成酶(SPS)活性和蔗糖含量低,籽粒蔗糖合成酶(SS)活性低,籽粒蔗糖含量高,籽粒ADPG焦磷酸化酶(AGPP)、可溶性淀粉合成酶(SSS)、束缚态淀粉合成酶(GBSS)活性低,淀粉积累量低。相关分析表明,籽粒中AGPP、SSS、GBSS与直、支链及总淀粉积累速率、籽粒灌浆速率呈极显著正相关,说明这几种酶对促进籽粒淀粉的积累起重要作用。

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.