[Multi-gene molecular identification and pathogenicity analysis of pathogens causing root rot of Atractylodes lancea...

To clarify the species, pathogenicity, and distribution of the pathogens causing the root rot of Atractylodes lancea in Hubei province, the tissue separation method was used to isolate the pathogens from root rot samples in the main planting areas of A. lancea in Hubei. Based on the preliminary identification of the Fusarium genus by the internal transcribed spacer(ITS) sequence, three housekeeping genes, EF1/EF2, Btu-F-FO1/Btu-F-RO1, and FF1/FR1, were amplified and sequenced. Subsequently, a phylogenetic tree was constructed based on these TEF gene sequences to classify the pathogens. The pathogenicity of these strains was determined using the root irrigation method. A total of 194 pathogen strains were isolated using the tissue separation method. Molecular identification using the three housekeeping genes identified the pathogens as F. solani, F. oxysporum, F. commune, F. equiseti, F. tricinctum, F. redolens, F. fujikuroi, F. avenaceum, F. acuminatum, and F. incarnatum. Among them, F. solani and F. oxysporum were the dominant strains, widely distributed in multiple regions, with F. solani accounting for approximately 54% of the total isolated strains and F. oxysporum accounting for approximately 34%. Other strains accounted for a relatively small proportion, totaling approximately 12%. The results of pathogenicity determination showed that there were certain differences in pathogenicity among strains. The analysis of the pathogenicity differentiation of the widely distributed F. solani and F. oxysporum strains revealed that these dominant strains in Hubei were mainly highly pathogenic. This study determined the species, pathogenicity, and distribution of the pathogens causing the root rot of A. lancea in Hubei province. The results provide a scientific basis for further understanding the root rot of A. lancea and its epidemic occurrence and scientifically preventing and controlling this disease.