麦长管蚜胁迫下不同小麦品种冠层光谱特征及其预测模型

[目的]构建不同小麦品种基于冠层光谱参数的麦长管蚜百株蚜量预测模型。[方法]采用便携式野外光谱仪测定不同百株蚜量下3个小麦品种‘1376’‘Amigo’和‘小偃-22’的冠层高光谱反射率,并对冠层反射率与百株蚜量进行了相关和回归分析。[结果]在400~900 nm波段内,随着百株蚜量的增加,3个小麦品种冠层光波反射率下降,且部分波段内达到极显著水平(P<0.01);选择可见光波段的405 nm、近红外波段的835 nm作为3个小麦品种共有的特征波长点,构建出的3个小麦品种的百株蚜量预测模型的显著性均达到极显著水平(P<0.01),且3个小麦品种405 nm波长点模型均优于835 nm波长点。[结论]利用高光谱信息同时预测不同小麦品种麦长管蚜百株蚜量是完全可行的。
[Objectives]It is becoming more and more important to use mixed wheat cultivars to control wheat pests. The paper studied the key spectral parameters and models of different wheat cultivars under being damaged by different amount of grain aphid Sitobion avenae. These results contribute to estimating the amount of aphids per one hundred plants under mixed wheat cultivars. [Methods]Three cultivars wheat(‘1376’ ‘Amigo’ and ‘Xiaoyan-22’)and four damage levels of slight(20-30 aphids per hundred plant), moderate(450-550 aphids per hundred plant), moderate and serious side(1 200-1 300 aphids per hundred plant), and serious(2 200-2 300 aphids per hundred plant)were used in this study. Hyperspectral reflectance within 400-900 nm of these cultivars wheat canopies were measured by the ASD portable spectrometer under different damage levels. The correlations and regressions were analyzed between single wavebands, vegetation indices of Ratio Vegetation Index(RVI)and Normalized Difference Vegetation Index(NDVI)and the amount of aphids per one hundred plants. [Results]The percent reflectance on three cultivars wheat canopy decreased with the increase of infestation by wheat aphid at visible light wave bands(400-700 nm)and near-infrared wave bands(701-900 nm). Furthermore, the percent reflectance significant difference occurred in some wave bands(P<0.01). The sensitive wave bands included visible wave band of 405 nm and near-infrared band of 835 nm on all three cultivars wheat. These sensitive bands were selected out to calculate the vegetation indices of RVI and NDVI. Unvaried linear function models for determining the amount of aphids per one hundred plants were established based on above sensitive wave bands, RVI, and NDVI. Meanwhile, the model equation based on the two sensitive wave bands had very significant correlation with the amount of aphids per one hundred plants for all three cultivars wheat, and the model according to the spectral reflectivity at 405 nm were optimum for all cultivars wheat, i.e.for‘1376’, y=-100 327.99x+2 189.09(P=0.002), for‘Amigo’, y=-18 185.44x+2 196.83(P=0.004), and for ‘Xiaoyan-22’, y=-46 758.63x+3 047.74(P=0.008). However, the model equation based on the RVI and NDVI had