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为了解糯玉米氮素积累进程的变化规律,阐明不同生育时期氮素积累的基因型差异及其对产量形成的作用,分析了31个糯玉米品种在同一施氮水平下四叶期、拔节期、大口期(12叶期)、开花(吐丝)期、鲜穗采收期和成熟期的植株氮素积累量。结果表明,植株氮素含量随生育进程逐渐下降,植株氮素积累量随生育进程的增加呈不对称的S型曲线变化,可用Richards方程拟合。不同品种各生育时期的氮素含量和积累量均存在显著差异。鲜穗高产品种主要在大口至开花阶段增加了吸氮量;而鲜子粒及成熟子粒高产品种主要在大口至开花,其次在开花至鲜穗采收阶段增加了吸氮量。通径分析表明,氮素积累过程主要影响氮素积累总量的高低,而对氮素利用效率影响较小。氮素积累过程S型曲线的Richards方程特征参数品种间差异显著。最大积累速率大、活跃积累期长、快增期的积累速率大和持续时间长对提高品种的氮素吸收总量有利。属于高产、氮素吸收量大、氮素利用效率高的基因型有6个品种,其大口至开花及开花至鲜穗采收阶段的吸氮量平均值分别为1.136和0.554 g/plant,比其它品种分别高24.3%和37.8%;最大积累速率和快增期的积累速率分别为0.068和0.059 g/(d.plant),比其它品种分别高15.8%和15.9%。活跃积累期和快增期的持续时间平均值分别为63.4和29.5 d,比其它品种分别延长了1.9和0.9d。
In order to understand the variation of nitrogen accumulation in waxy corn and clarify the genotypic differences of nitrogen accumulation in different growth stages and their effects on the yield formation, the effects of four waxy corn varieties on the four-leaf stage and jointing stage , Large-mouth (12-leaf stage), flowering (silking), ear-harvest and maturity of plant nitrogen accumulation. The results showed that the plant nitrogen content decreased with the growth process, and the plant nitrogen accumulation showed an asymmetric sigmoid curve with the increase of the growth process, which could be fitted by Richards equation. There were significant differences in nitrogen content and accumulation in different varieties during each growth period. The high-yielding cultivars of fresh ear increased nitrogen uptake mainly from the big mouth to the flowering stage; while the high-yielding cultivars of fresh and mature grains were mainly from big mouth to flowering, followed by increased nitrogen uptake during flowering to harvest of fresh ear. Path analysis showed that nitrogen accumulation mainly affected the total amount of nitrogen accumulation, but had little effect on nitrogen use efficiency. The variation of Richards equation characteristic parameters of S curve in nitrogen accumulation process was significant. The largest accumulation rate, active accumulation period, rapid accumulation period and the long duration of the variety to improve the total nitrogen absorption of favorable. Six genotypes with high nitrogen uptake and high nitrogen use efficiency had the highest N uptake of 1.136 and 0.554 g / plant respectively from the large mouth to the flowering and flowering stage until fresh ear harvest stage The other varieties were 24.3% and 37.8% higher, respectively. The accumulation rates of maximum and rapid accretion were 0.068 and 0.059 g / d.plant respectively, 15.8% and 15.9% higher than those of other cultivars. The average durations of active accumulation and rapid increase were 63.4 and 29.5 d, respectively, which were 1.9 and 0.9 d longer than those of other cultivars.