Abstract: [Objective]The objectives of this study were to identify the pathogens causing anthracnose of Camellia oleifera(oil-tea) in nursery in China and to reveal the resistance of anthracnose pathogens to fungicides, in order to provide targeted strategy for controlling oil-tea tree anthracnose.[Method]The anthracnose pathogen was isolated from C. oleifera in nursery, and its ApMat gene was amplified and sequenced by PCR. The anthracnose pathogen species were identified by phylogenetic analysis. The resistance of all strains to fungicides carbendazim, ethomyl, tebuconazole and prochlorazolam was further determined by differentiated dose method.[Result]Based on phylogenetic analysis of the ApMat locus with the neighbor-joining (NJ) method, the 95 isolates of anthracnose pathogens, collected from oil-tea trees in nurseries in Hunan, Jiangxi, Hainan, and Guangdong provinces (the important oil-tea trees production regions in China), were found belonging to four species of Colletotrichum genus:C. fructicola,C. siamense,C. camelliae and C. gloeosporioides. Among them, C. fructicola was the most abundant, accounted for 87.4%. Among these 95 strains, 31 were respectively resistant to either carbendazim or tebuconazole, with 6 of the 56 showing resistance to both carbendazim and tebuconazole. In contrast, all 95 strains were very sensitive to prochloraz. Two strains were resistant to three fungicides, carbendazim, carbendazim and tebuconazole. Comparison of the β-tubulin amino acid sequences between carbendazim-resistant and susceptible strains of Colletotrichum spp. revealed that 29 resistant strains had a mutation leading to an amino acid substitution at the position 198, from glutamicacid in the susceptible strain to alanine in the resistant strains.Furthermore, the 200th amino acid was also mutated from phenylalanine (Phe) to tyrosine (Tyr) of β-tubulin in the two strains showing resistance to both carbendazim and carbendazim.[Conclusion]The results suggest that the Colletotrichum spp. collected from oil-tea tree nurseries in China have developed serious resistance to carbendazim, diethofencarb and tebuconazole but not to prochloraz.

Key words: Camellia oleifera, anthracnose, Colletotrichum spp, fungicide resistance