Submitted to: American Society of Sugarbeet Technologists
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2004
Publication Date: March 4, 2005
Citation: Panella, L.W. 2005. Pathogenicity of different anastomosis groups and subgroups of rhizoctonia solani on sugar beet. Proc. American Society of Sugarbeet Technologists. 33rd Meeting (Agriculture) Palm Springs, CA. March 2-5, 2005. Annual Meeting abstracts p. 166. 2005. Technical Abstract: ABSTRACT: Rhizoctonia root and crown rot (caused by Rhizoctonia solani) continues to be a problem in most sugar beet-growing areas in the United States, and is a growing problem world wide. Understanding the genetic variability of the pathogen provides information for diagnosis and management of the disease. Ninety four isolates of Rhizoctonia solani representing fifteen Anastomosis Groups (AG) or subgroups were tested for pathogenicity on susceptible sugar beet hybrid, 'Monohikari', and the resistant germplasm, 'FC708CMS'. Ground, R. solani-infested barley was placed by the root of 10 wk old plants in pots in the greenhouse. Roots were evaluated on a Disease Index (DI) of 0 (no damage) to 7 (dead), 28 d after inoculation. Data were analyzed using PROC MIXED (SAS), and means were separated with Dunnett's one-tailed t test, which tested if any isolate caused a significantly (p = 0.05) higher DI than the uninoculated control. With few exceptions, only isolates from AG-2-2 (IIIB or IV) were pathogenic on sugar beet, and those from AG-2-2 IIIB were more virulent than the isolates from the AG-2-2 IV subgroup.