*2.5. Analytical Framework*

Figure 3 presents the data, methods, and processing steps for the identification of MDMV and severity monitoring of its infection. First, the spectral differences between the healthy and infected leaves with different degrees of reddening were analyzed in order to explore the spectral response characteristics of MDMV-infected leaves, which were the basis for further analyses in the present study. Then, the LDA and SVM classification models for MDMV were constructed based on single-band spectral information (Rλ), twoor three-band VIs, and full-spectrum arbitrary two-band combined vegetation index (VIc). Finally, high-precision Anth estimation models for healthy and red leaves were constructed based on three types of spectral parameters. The details are provided in Results.

**Figure 3.** Analysis process of this study.
