The effects of different fertilization Ievel on grain protein and free amino acid content of organs above ground of different wheat variety

In this article the change of the free amino acid content of the different variety wheat organs above the ground and the relationship with the grain protein along with the modulation of nitrogen nutri-tion were studied. The results showed that the free amino acid content of leaf, ear axis and husks all increased continuously after anthesis and reached the maximum value after anthesis 14 days,then began to declined. The free amino acid content of stem and sheath increased slowly after anthesis and reached the maximum value until anthesis 21 days. Commonly,The Free amino acid content of grain declined continu-ously after anthesis. The free amino acid content of different organs above the ground and the protein content of mature grain were significant or best significant positive correlation. The results showed that the free amino acid was supplied abundantly so it was benefit for the accumulation of grain protein. Increased nitrogenous fertilizer can increase the free amino acid content of different organs above the ground and that can advance the synthesis of the grain protein and increase the content of grain protein. The difference of the grain protein content in varieties was resulted by the transportation of amino acid from nutrition organs above the ground to grains.