Investigation of specific molecular marker and EC50 values of guazatine for Geotrichum citri-aurantii on citrus in China

•Two pairs of specific primers, 2996-R&F and 4989-R&F, targeting G. citri-aurantii, were successfully developed.•We identified 25 G.citri-aurantii isolates using the 2996-R&F and 4989-R&F.•The average median effective concentration (EC50) values of G.citri-aurantii isolates from Wuhan (0.1295 µg/ml), Guilin (0.0826 µg/ml) and Ganzhou city (10.3313 µg/ml) is 1.4 times, 2.2 times and 182 times that of positive control, separately.