Climate Effects on Flavonoid Content of Zanthoxylum bungeanum Leaves in Different Development Stages

To investigate associations between meteorological parameters and flavonoid content of Zanthoxylum bungeanum leaves (ZBL) in different development stages, three cultivars of Meifengjaio, Shizitou, Qin'an Yihao were selected as experimental material. The flavonoid contents of ZBL were evaluated based on HPLC-MS technology (High Performance Liquid Chromatography - mass spectrograph). Results showed that the total flavonoid content of three ZBLs had significant difference, presented as Shizitou > Qin'an Yihao > Meifengjiao. However, its variation tendency remained nearly constant, with maximums between May and June, and lowest in August. Seven key flavonoids contents (quercitrin, hyperoside, afzelin, quercetin-3-O-glucoside, epicatechin, catechin, rutin.) were identified. The Pearson correlation analysis of 36 meteorological parameters and 7 flavonoids contents indicated that 16 meteorological significantly affected the flavonoid content in ZBL, of which temperature, water vapor pressure and other parameters were significantly negatively correlated with flavonoid content, and wind speed was significantly positive. Quercetin-3-O-glucoside, afzelin, epicatechin and catechin were significantly affected by meteorological parameters, while rutin, quercitrin and ghyperoside were less. Finally, we selected the total flavonoid content in Shizitou as representative to fit with 16 key meteorological parameters respectively, and obtained the specific relationship expression, which revealed the functional relationship between climate and total flavonoid content. This study provided a theoretical basis for the rational harvesting of ZBL and promoted the further development and utilization of it.