Isolation, characterization, and pathogenicity of species causing crown rot of wheat.

Fusarium crown rot (FCR) is one of the most important soilborne diseases affecting wheat production. To investigate the diversity of the pathogens causing this disease, 199 diseased wheat samples were collected from 13 cities in Shandong province. In total, 468 isolates were obtained, and from these isolates, 11 species were identified based on phylogenetic analyses with the translation elongation factor-1α (), RNA polymerase II largest subunit (), and RNA polymerase II second largest subunit () gene sequences. Of these isolates, 283 were identified as and the remaining isolates were identified as ( = 113), ( = 28), ( = 18), ( = 13), ( = 5), ( = 3), ( = 2), ( = 1), ( = 1), and ( = 1), suggesting that is the dominant pathogen of FCR of wheat in Shandong province. Pathogenicity tests demonstrated that all 11 species could cause typical symptoms of FCR on wheat seedlings. The results of the study indicate that a greater diversity of species can cause FCR of wheat in Shandong province than that has been previously reported. This is the first report in the world of , , and as pathogens causing FCR in wheat.