小麦冠层反射光谱与籽粒蛋白质含量及相关品质指标的定量关系

Relationship of Grain Protein Content and Relevant Quality Traits to Canopy Reflectance Spectra in Wheat

研究了不同施氮水平下小麦籽粒蛋白质含量及相关品质性状与冠层反射光谱、植株氮素状况之间的定量关系。结果表明,小麦灌浆期冠层反射光谱可以用来直接预测籽粒蛋白质含量、沉降值和降落值,成熟期冠层反射光谱对籽粒醇溶蛋白和谷蛋白含量的监测具有较高的可靠性;籽粒蛋白质含量与花后14d叶片含氮量的相关性较好,并且花后14d比值指数RVI(1220,710)能准确反演叶片含氮量,进而可以间接地预测籽粒蛋白质含量。据此提出了小麦籽粒蛋白质含量及相关品质指标的两种监测技术途径:基于灌浆期反射光谱的直接预测和基于花后14d(灌浆中期)叶片含氮量的间接估测。

Quantitative relationships of grain protein content and relevant quality traits to canopy reflectance spectra and plant nitrogen status in wheat were investigated in the experiments under varied nitrogen conditions. The results showed that grain protein content, sedimentation value and falling number could be predicted by canopy reflectance spectra during filling. Monitoring of gliadin and glutenin contents in grains by canopy reflectance spectra at maturity showed high reliability. There were high correlations between grain protein content and leaf nitrogen content at 14 days after anthesis (mid-filling stage), and the latter could be well estimated by the ratio vegetation index RVI (1220, 710) at this stage. Therefore, the reflectance spectra at mid-filling could be used to monitor grain protein content indirectly. These results suggest two approaches to monitor grain protein content and relative quality traits in wheat: direct prediction based on reflectance spectra during filling and indirect estimation based on leaf nitrogen content at mid-filling stage.