Taxonomical identification of Chinese cabbage yellows inhibitory fungus isolated from disease suppressive soil

A Chinese cabbage yellows-suppressing fungal strain (S69) isolated from a suppressive field soil to the disease was identified to be Pseudothielavia terricola, based on phylogenetic analyses and morphological observations. Phylogenetic studies were completed using individual and combined data sequences of ITS-LSU, rpb2, and tub2, and indicated that the identified fungal strain belonged to a monophyletic clade that also included P. arxii and P. terricola. Morphological observations revealed that the fungal ascospores had apical germ pores, a distinctive characteristic of P. terricola but not of P. arxii. Additional observed morphological characteristics of S69 were also similar to P. terricola.