Characterizing the pathogenicity and mycotoxin production capacity of Fusarium spp. causing root rot of Angelica sinensis in China.

Root rot is a very destructive soil-borne disease, which severely affects the quality and yield of Angelica sinensis in major planting areas of Gansu Province, China. Twelve Fusarium strains were identified from root rot tissue and infected soil in the field, by comparing each isolate strain internal transcriptional spacer, translation elongation factor 1-α sequence and RNA polymerase second largest subunit gene (RPB2) with the sequences of known fungal species in the NCBI database. Of these isolates, four were F. acuminatum, followed by three F. solani, two F. oxysporum, and one each of F. equiseti, F. redolens, and F. avenaceum. Under greenhouse conditions, pathogenicity testing experiment was carried out using five strains: two F. acuminatum, one F. solani, one F. oxysporum, and one F. equiseti. Among them, the incidence of F. acuminatum-induced root rot on A. sinensis was 100%; hence, it was the most aggressive. Liquid chromatography was used to show that F. acuminatum was capable of producing neosolaniol (NEO), deoxynivalenol (DON), and T-2 toxins. Of these, the level of NEO produced by F. acuminatum was high, compared with the other two toxins. By isolating Fusarium spp. and characterizing their toxin-producing capacity, this work provides a new information for effectively preventing and controlling A. sinensis root rot in the field, as well as improving the quality of its medicinal materials. Keywords: Angelica sinensis, Fusarium spp., mycotoxins, pathogenicity tests, root rot disease.