Hyperspectral Characteristics and SPAD Estimation of Wheat Leaves under CO 2 Microleakage Stress.

Abstract

To non-destructively and rapidly monitor the chlorophyll content of winter wheat leaves under CO 2 microleakage stress, and to establish the quantitative relationship between chlorophyll content and sensitive bands in the winter wheat growing season from 2023 to 2024, the leakage rate was set to 1 L/min, 3 L/min, 5 L/min, and 0 L/min through field experiments. The dimensional reduction was realized, fractional differential processing of a wheat canopy spectrum was carried out, a multiple linear regression (MLR) and partial least squares regression (PLSR) estimation model was constructed using a SPA selection band, and the model's accuracy was evaluated. The optimal model for hyperspectral estimation of wheat SPAD under CO 2 microleakage stress was screened. The results show that the spectral curves of winter wheat leaves under CO 2 microleakage stress showed a "red shift" of the green peak and a "blue shift" of the red edge. Compared with 1 L/min and 3 L/min, wheat leaves were more affected by CO 2 at 5 L/min. Evaluation of the accuracy of the MLR and PLSR models shows that the MLR model is better, where the MLR estimation model based on 1.1, 1.8, 0.4, and 1.7 differential SPAD is the best for leakage rates of 1 L/min, 3 L/min, 5 L/min, and 0 L/min, with validation set R 2 of 0.832, 0.760, 0.928, and 0.773, which are 11.528, 14.2, 17.048, and 37.3% higher than the raw spectra, respectively. This method can be used to estimate the chlorophyll content of winter wheat leaves under CO 2 trace-leakage stress and to dynamically monitor CO 2 trace-leakage stress in crops.

Plant phenotyping relevance

小麦葉のSPAD／クロロフィル含量をハイパースペクトルから推定するモデルを構築・検証しており、植物表現型の取得・推定手法が中心である。

Code and data availability

The article describes field hyperspectral/SPAD measurements and MLR/PLSR modeling, but contains no data availability statement, no public dataset deposit, and no code availability or repository URL. The only URL present is the CC BY license link, which is not a paper-specific asset.

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