Diversity and Pathogenicity of Six Species from in China.

Walnut ( L.) is cultivated extensively in China for its substantial economic potential as a woody oil species. However, many diseases caused by greatly affect the health of trees. The present study revealed the presence of species from . A total of six species of were isolated from twigs of in three provinces in China, including two known species ( and ) and four novel species (, , and ). Phylogenetic relationships of the new species were determined by multilocus phylogenetic analyses based on partial sequences of the internal transcribed spacer (ITS) region, calmodulin () gene, histone H3 () gene, translation elongation factor 1-α () gene and β-tubulin () gene. Pathogenicity tests indicated that all species obtained in this study were confirmed as pathogens of . This study deepens the understanding of species associated with several disease symptoms in and provides useful information for effective disease control.