Identification of Pathogen Causing Powdery Mildew of Tartary Buckwheat and Analysis of Its Pedigree

Purpose To identify and analyze the pathogen of tartary buckwheat powdery mildew and determine its position in the powdery mildew pedigree.

Methods The tartary buckwheat powdery mildew pathogen was identified based on spore morphology observation, pathogenicity test and phylogenetic tree analysis of internal transcribed spacer (ITS) and ribosomal large subunit (LSU) sequence, and multiple sequence alignment and cluster analysis of sequences were carried out.

Results The pathogen of powdery mildew of tartary buckwheat was identified as Erysiphe polygoni. Through ITS multiple sequence alignment and cluster analysis, it was found that the powdery mildew (607 bp fragment, MW494930.1) was 100.00% similar to E. polygoni (KP076437.1) on common buckwheat. The similarity of that ITS amplification sequences with 16 strains collected from rhubarb, sorrel, polygonum, ribbonbush and coral vines were also higher than 98.83%. A 910 bp fragment (OK490143) was obtained based on LSU sequence amplification, which showed 99.89% similarity with the strain of the E. polygoni (MT361769.1) on sorrel.

Conclusion The tartary buckwheat powdery mildew is identified as E. polygoni, which belonged to Erysiphe, Erysiphales, Ascomycota. It provides a basis for the control of tartary buckwheat.