Decreasing N application proportion after elongation stage could decrease the accumulation rates of amylose, amylopectin and starch from 14th to 35th DAA and amylose content, but increase the contents of amylopectin and starch at maturity.

• 5植株体内含氮率在越冬始期最高，随生育进程推移而逐渐下降，可溶性糖含量在越冬始期、孕穗一开花期含量较高，拔节期含量较低，C/N比值与糖含量变化趋势相似。 拔节、孕穗、开花期植株糖含量及糖氮比与籽粒淀粉含量呈显著正相关。