低氮胁迫对不同基因型玉米生物产量和氮吸收率动态变化的影响

通过盆栽试验,在施氮和不施氮条件下,对6种不同基因型的玉米材料在拔节、开花、灌浆和成熟等不同生育时期的生物产量、体内氮素含量、氮素积累量和氮素吸收率等性状进行了分析。结果表明:施氮条件下,开花期之后的生物产量、氮素含量和氮素积累量显著或极显著高于不施氮处理,而氮素吸收率仅灌浆期不施氮处理显著高于施氮处理;不同遗传背景材料对低氮胁迫反应不同,除农大108杂种优势表现明显外,许178开花期和灌浆期的生物产量、氮积累量和氮吸收率等均居前列,高于或显著高于其他自交系,而其他材料波动较大。拔节后随生育时期推进,植株氮素含量稳中有降,而生物产量、氮积累量和氮吸收率呈递增态势,其间存在极显著正相关(R0.98),增幅因材料而异,开花后变异系数约为拔节期3倍,尤其不施氮处理施氮处理,农大108、许178和L2增幅较大,证明其在低氮胁迫条件下更能显示其氮高效利用特性。

Dynamic Variation of Biomass and Nitrogen Absorption Ratio of Different Genotypes in Maize under Low Nitrogen Stress

In this investigation, the biomass, nitrogen content, nitrogen accumulation and nitrogen absorption ratio(NAR) of maize at different developing stages for an elite hybrid Nongda108, its parents and its three F2:4 family lines with different nitrogen use efficiency(NUE) were analyzed under nitrogen applied and no N applied conditions by means of pot cultivation in the field. The results showed that the biomass, nitrogen content and nitrogen accumulation were higher or much higher under nitrogen applied than no N applied conditions after flowering stage, but the NAR was lower under nitrogen applied than no N applied conditions. Beside for the hybrid Nongda108 appearing obvious heterosis, the inbred line Xu178 had higher or significant higher in biomass, nitrogen accumulation and NAR in flowering and grain filling stages than the other inbred lines. The mean nitrogen content tend to be lightly decreased over stages, while the nitrogen accumulation and the NAR increased with its biomass, and highly significant relationships existed among them(R>0.98), also the increasing range varied with genotypes, and the coefficient of variations after flowering stages were tree times higher than that of jointing stage, especially under no N applied conditions. Nongda108, Xu178 and L2 had higher increasing ranges, which referred that they were insensitive to low N stress.