春小麦品种氮的吸收积累和转运特征及与籽粒蛋白质的关系

The Absorption, Accumulation and Translocation of Nitrogen and Their Relationships to Grain Protein Content in Spring Wheat Variety

春小麦个体发育的各个时期,不同器官全N含量均存在着差异,表现为叶片>叶鞘>茎杆。叶片、叶鞘、茎杆和籽粒N积累峰值依次出现在孕穗期、抽穗期、开花盛期和乳熟末期。开花前N素主要积累在叶片中,生育后期籽粒成为N素的主要贮存场所。籽粒N主要来自开花前营养器官贮存N的再分配,再分配N占籽粒N的53.0％～80.8％,各营养器官贮存N对籽粒N贡献的大小顺序是叶片>茎杆>叶鞘。在籽粒灌浆过程中,籽粒N素含量的变化曲线呈“凹”形,籽粒N素的积累曲线呈“S”形。籽粒蛋白质含量与各生育时期单株和营养器官全N含量均呈显著的正相关,与N积累量、N运转率及N收获指数相关均不显著。籽粒产量和蛋白质含量都受供N水平的影响,品种获得最高籽粒产量和蛋白质含量所需N肥的量是不同步的。

There were differences in the total N content of different vegetative organs at different stages of individual development in spring wheat. The total N content in the leaf blade was higher than that in the leaf sheath and the stem. The peak values of the N accumulation in the leaf blade, leaf sheath, stem and grain appeared successively at the booting stage, heading stage, full anthesis and late milky stage. N was mainly accumulated in the leaves before anthesis, and in the grains after that. About 53. 0%-80. 8% of the N in the grains come mainly from redistribution of the N accumulated in different vegetative organs before anthesis. The order of their contribution to the grain N is leaf blade>stem>leaf sheath. The total N content in the grains was higher initially, then it decreased, and increased again until maturity. But a 'S' curve of grain-N accumulation was observed. The grain protein content was significantly positively correlated to the total N content accumulated in single plants and different vegetative organs at different growth stages. But there were little positive correlations between the grain protein content and the N accumulation, N-translocation rate or N-harvest index. Both the grain yield and the protein content were affected by the application levels of N fertilizer. The optimum rates of N fertilizer application for maximum grain yield and protein content were different for different cul-tivars.