春小麦籽粒淀粉和蛋白质积累与底物供应的关系

利用产量和蛋白质含量不同的三个春小麦品种，在盆栽条件下，研究了籽粒灌浆过程中淀粉和蛋白质积累与可溶性糖、游离氨基酸含量变化的关系。结果表明，开花后5～20d三个品种籽粒可溶性糖含量急剧下降，对应时期的淀粉含量快速上升，后期当可溶性糖含量回升时，其相应淀粉含量下降或增加的幅度很小。籽粒游离氨基酸含量随着灌浆进程渐次降低，品种间蛋白质含量的变化与游离氨基酸的变化一致。所有品种淀粉积累速率变化呈抛物线型变化，高产中蛋白品种的淀粉积累速率最高。进一步认为，可溶性糖作为淀粉合成的底物向淀粉的转化可能更多地依赖于籽粒利用和合成能力的大小，而蛋白质积累更多地直接依赖供应源。

Relationship between Starch, Protein Accumulation and Substrate Supply during Grain Filling in Spring Wheat

Pot experiment was conducted to investigate the relationship between starch,protein accumulation and soluble sugar, total free amino acid contents during grain filling period with three wheat genotypes differing in both protein and yield. The results indicate that soluble sugar contents decreases dramatically from 5 to 20 days after anthesis, and starch content increases correspondingly. At later stage, there is slight rise or decline of starch content when soluble sugar content increases. As seeds develop, the total free amino acids decline gradually and the change of varietal protein content is consistent with free amino acids. The starch accumulation rate shows the pattern of parabola in all cultivars tested, and high yield and middle protein cultivar has the highest accumulation rate. It is proposed that the accumulation of starch is mainly dependent on ability of grain to utilize or syhthesize substrate and that of protein is more directly dependent upon restriction of source strength.