Tea polyphenol is a potential antifungal agent for the control of obligate biotrophic fungus in plants

Tea polyphenol ( TP ) exhibits broad‐spectrum antimicrobial properties. In this study, the in vitro and in vivo antifungal activities of TP on Puccinia striiformis f.sp. tritici ( Pst ), which is an obligate biotrophic fungus that causes severe wheat stripe rust disease, were evaluated to investigate the control efficacy of TP . In vitro experiments showed that, at a concentration of 1.0 mg/ml, TP significantly suppressed urediniospore germination and caused the aberrant growth of germ tubes. The inhibition ratio reached 100% by increasing the TP concentration. In vivo experiments showed that TP reduced incidence rate and the uredia coverage rate in a dose‐ and application time‐dependent manner. TP treatment also induced the aberrant differentiation of Pst on wheat leaves. Results suggest that the ideal TP concentration range is 20–40 mg/ml, and TP may be a potential antifungal agent for the control of obligate biotrophic fungus in plants.