Using hyperspectral reflectance to detect changes in photosynthetic activity in Atractylodes chinensis leaves as a function of decreasing soil water content.

Abstract

Application of hyperspectral reflectance technology to track changes in photosynthetic activity in Atractylodes chinensis (A. chinensis) remains underexplored. This study aimed to investigate the relationship between hyperspectral reflectance and photosynthetic activity in the leaves of A. chinensis in response to a decrease in soil water content. Results demonstrated that the reflectance in both the visible light and near-infrared bands increased in conjunction with reduced soil water content. The derived vegetable indices of photochemical reflection index (PRI) and the pigment-specific simple ratio of chlorophyll b (PSSR_b) gradually decreased. In contrast, the normalized difference in water index (NWI) and water index (WI) increased. Moreover, significant correlations were observed between PRI, PSSR_b, WI, and NWI and photosynthetic activity indices, namely photosynthetic rate and total performance index. Consequently, hyperspectral reflection represents a productive approach for evaluating the influence of water deficit on photosynthetic activity in A. chinensis leaves.