Fig. 2. FT-IR spectra analysis of P. expansum F-WY-12-02 under Cin/Cit treatment. (A and B) FT-IR spectra of the second derivative (900–1800 cm⁻¹, 2800–3100 cm⁻¹, respectively). (C) PCA 3D scores. (D) PCA loading plot. Arrow referred to the greatest contribution to the total variance in the FT-IR spectral data.