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ARS Home » Midwest Area » East Lansing, Michigan » Sugarbeet and Bean Research » Research » Publications at this Location » Publication #306668
Title: The prevalence of different strains of Rhizoctonia solani associated with Rhizoctonia crown and root rot symptoms in Ontario sugarbeet fields

Author
item TRUEMAN, C - University Of Guelph
item Hanson, Linda
item LEBOEUF, J - Omafra (ONTARIO MINISTRY OF AGRICULTURE & FOOD/RURAL AFFAIRS)

Submitted to: Canadian Phytopathological Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2012
Publication Date: 1/1/2013
Citation: Trueman, C.L., Hanson, L.E., Leboeuf, J.E. 2013. The prevalence of different strains of Rhizoctonia solani associated with Rhizoctonia crown and root rot symptoms in Ontario sugarbeet fields [abstract]. Canadian Phytopathological Society Meeting. 35:1, 99-132.

Interpretive Summary:

Technical Abstract: Rhizoctonia crown and root rot (RCRR) [Rhizoctonia solani Kühn] is an important disease of sugarbeets in southwestern Ontario, Canada. A survey of commercial sugarbeet fields was completed in 2010 and 2011 to determine the range of R. solani anastomosis groups (AGs) and inter-specific groups (ISGs) associated with RCRR in this region. Soil immediately surrounding plants with RCRR symptoms was collected and stored at 4 'C. Sugarbeet cv. ‘Crystal 824’ was seeded in pots containing the collected soil, grown in a greenhouse, and monitored for dampingoff. Rhizoctonia solani cultures from 55 and 45 soil samples were obtained in 2010 and 2011 respectively by isolating the fungus from symptomatic seedlings. Standard hyphal fusion assays showed that 69 and 80% of cultures isolated in 2010 and 2011 belonged to AG-2-2. ISG identification using differential temperature assays for 2011 samples is ongoing; however 35 and 24% of all isolates collected in 2010 were AG-2-2 IIIB and AG-2-2 IV. AG-2-2 IIIB is considered more aggressive than AG-2-2 IV, and has a wider host range that includes corn and soybeans. In fields where AG-2-2 IIIB is present, there may be a higher risk of losses from RCRR when host crops precede sugarbeet plantings in the crop rotation.