水分胁迫对小麦光谱红边参数和产量变化的影响

在不同的水分胁迫梯度下，利用实验区小麦不同生长期光谱反射率观测数据，研究水分胁迫对小麦光谱反射率、红边参数及小麦产量的影响。首先分析水分胁迫对小麦光谱反射率的影响，然后利用小麦光谱反射率的一阶微分得到小麦光谱反射率的红边位置和红边幅度参数，分析了水分胁迫对小麦光谱红边参数的影响，最后利用水分胁迫下的红边幅度和小麦产量的关系，阐述了小麦水分胁迫下的光谱反射率特征与小麦产量的关系。研究结果表明，水分胁迫下小麦的红边位置在生长期前期出现红边位置红移现象，生长期后期出现红边位置蓝移现象。水分胁迫下的小麦的红边幅度在不同的生长期表现出不同的变化特征：生长期初期随着水分胁迫的增加而红边幅度增大，生长期后期随着水分胁迫的增加而红边幅度减小。小麦的红边幅度在拔节生长期前与小麦产量呈负相关而拔节生长期之后呈正相关，且不同生长期小麦的红边幅度与小麦的产量的相关系数不同。

Effects of Water Stress on Red-Edge Parameters and Yield in Wheat Cropping

The objective of the present paper is to study the influence of water stress on wheat spectrum red edge parameters by using field wheat spectrum data obtained from water stress experiment. Firstly, the authors analyzed the influence of water stress on wheat spectrum reflectance. Then the authors got the wheat red edge position and red edge peak through calculating wheat spectrum first-order differential and analyzed the influence of water stress on wheat red edge parameters. Finally the authors discussed the relationship between red peak and wheat yield. The results showed that the wheat red edge position shows “red shift” at the beginning of the wheat growth period and “blue shift” at the later period of the wheat growth period under the water stress experiment. Also, the red edge peak of the wheat showed that red edge peak increased with the water stress sharpening at the beginning of the wheat growth period, and then the red edge peak reduced with the water stress sharpening. The wheat red edge peak presented positive correlation with the wheat yield before the elongation period, and exhibited negative correlation after that period.