Abstract:

To determine the identity of pathogenic Fusarium strains causing Scutellaria baicalensis root rot disease， a total of 136 diseased roots were collected were isolated by a tissue separation method in Longxi， Gansu Province during the years of 2019 to 2021. Based on the pathogen morphological characteristics， and general primer， specific primer and translation elongation factor （TEF） sequence analysis of Fusarium， the pathogens from the collected samples were identified as belonging to 83 Fusarium strains identified as Fusarium oxysporum （39.8%）， Fusarium solani （36.1%）， Fusarium acuminatum （16.9%）， Fusarium redolens （4.8%）， Fusarium equiseti （1.2%） and Fusarium flocciferum （1.2%）. Hence， F. oxysporum and F. solani were the dominant pathogens. Pathogenicity testing showed that the pathogenicity of different Fusarium species differs， and the pathogenicity of each strain within the same species also varied significantly. The relative disease index of F. oxysporum was 9.0 and was the strongest， that of F. redolens was 1.2 and wasthe weakest. F. equiseti and F. flocciferum displayed no pathogenicity. The major nutrient element contents in S. baicalensis roots did not change significantly after infection， while the contents of micro elements Zn， Mn and Fe increased significantly （P<0.05）. This is the first report of F. acuminatum and F. redolens causing root rot on S. baicalensis in China， and these data provide a theoretical basis for scientific diagnosis of this disease and study of the response of S. baicalensis to Fusarium infection.

Key words: Scutellaria baicalensis, root rot disease, Fusarium, element contents