Submitted to: American Society of Beet Sugar Technologists Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/3/2013
Publication Date: 6/14/2013
Citation: Hanson, L.E., Mo, T., Goodwill, T.R. 2013. Phoma species on beet: more cause disease than just Phoma betae. IN: Proceedings of the American Society of Beet Sugar Technologists. 37th Biennial Meeting, February 27 - March 3, 2013, Anaheim, California. 2013 CD-ROM.
Technical Abstract: Phoma can cause damage to sugar beet (Beta vulgaris) at multiple growth stages. It has historically been an important seedling disease, but this is largely managed by ensuring clean seed for planting. The pathogen also can cause a root rot, a leaf spot, and rotting of beets during storage. In the United States, the only pathogenic Phoma associated with beets has been Phoma betae. In Europe, other species of Phoma have been reported to cause symptoms on sugar beet. Phoma isolates from sugar beet in the United States were examined to determine whether there might be more species causing symptoms on beet. Phoma isolates had been collected as part of ongoing surveys for seedling diseases and root rot, and additional samples were collected from leaf spots. Isolates were examined for morphological characters on malt extract agar and oatmeal agar and a portion of the ITS region was sequenced. Of 16 isolates identified as Phoma by both morphological and molecular testing, eight were identified as P. betae while the remaining isolates showed highest identity with Phoma species other than P. betae, particularly in Phoma section Peyronellaea. Symptoms, including storage rot and leaf spot, were produced on beets inoculated with different Phoma species.