春小麦灌浆期籽粒沉淀值动态变化及氮磷肥与播期的影响

通过3个品质类型春小麦品种施肥和播期大田试验，建立了灌浆期籽粒沉淀值动态变化的曲线拟合方程，定量揭示籽粒沉淀值动态变化规律及氮磷肥与播期的影响效应.结果表明，自开花15 d始至成熟，籽粒沉淀值随时间变化呈先升高后降低的单峰曲线变化.在灌浆期籽粒沉淀值的动态变化过程中，不同基因型特点不同，且基因型间的关系也随之发生变化.各品种沉淀值积累速度的变化决定了成熟时高蛋白强筋品种沉淀值最高、高蛋白中筋品种次之、低蛋白弱筋品种最低.氮水平增加，高蛋白强筋和低蛋白弱筋品种沉淀值和曲线最高值降低，高蛋白中筋品种则明显升高；高蛋白强筋品种曲线最高值出现时间提前，而高蛋白中筋和低蛋白弱筋品种则推后.磷水平增加，高蛋白品种沉淀值和曲线最高值普遍提高，而低蛋白品种则降低；各基因型曲线最高值出现时间均推迟.氮磷（钾）素平衡配施是形成较高沉淀值的关键.在没有水分胁迫情况下，光温互作是影响籽粒沉淀值动态形成的首要条件，其次为降水；而≥10 ℃积温则为最敏感因子，即在较高光温条件互作前提下，增加灌浆期≥10 ℃积温则提高各基因型品种沉淀值.高蛋白比低蛋白品种更易受氮磷水平和气象条件影响.

Effects of nitrogen and phosphorus fertilization and sowing date on dynamic changes of grain sedimentation value during grain filling stage of spring wheat

In this paper, a field experiment with three genotypes ot spring wheat was conducted in Harbin in 2002 to investigate the effects of nitrogen (N) and phosphorous (P) fertilization rate and sowing date on the dynamic changes of grain sedimentation value (GSV) during their grain filling stage. The results showed that the dynamic changes of GSV with the days after anthesis fitted third-order convex curve, and the effects of genotypes and environmental factors on the dynamics of GSV formation could be expressed by the characteristic variables of the curve equation. Different genotypes had different GSV, and the dynamic change shapes in the accumulation velocity curves of GSV were responsible for its mature values. With the increase of N fertilization rate, the GSV and the peak values of its dynamic curves decreased in high protein-rich gluten and low protein-poor gluten genotypes but increased in high protein-medium gluten genotype, and the dates corresponding to the peak values were advanced in high protein-rich gluten genotype while postponed generally in high protein-medium gluten and low protein-poor gluten genotypes. With the increase of P fertilization rate, the GSV and the peak values of its dynamic curves increased generally in high protein genotype but decreased in low protein genotype, and the dates corresponding to the peak values were all postponed in the three genotypes. A rational ratio and rate of N and P fertilization was the key to elevate the GSV during grain filling stage. Under moderate rainfall, the interaction between temperature and sunlight was the predominant factor affecting the dynamic formation of GSV in different genotypes, and rainfall was the second factor. > or =10 degrees C accumulated temperature was the most sensitive factor affecting the dynamic formation of GSV because the enhancement of > or =10 degrees C accumulated temperature could elevate the GSV in the three genotypes. In general, high protein genotype was more easily affected by N and P fertilization rate and meteorological conditions than low protein genotype.