A survey of Rhizoctona groups on wheat and barley in the Continental U.S.
Root Disease and Biological Control Research
2010 Annual Report
1a.Objectives (from AD-416)
Survey wheat growing areas of the United States for Rhizoctonia groups and species infecting cereals (wheat and barley) and rotation crops.
1b.Approach (from AD-416)
Soil samples will be sent to Pullman by Syngenta staff and other University and ARS cooperators. Rhizoctonia will be isolated from the soils, cultured, and identified using sequencing of the ITS region. Representatives isolates will be tested in greenhouse for pathogenicity. Documents Trust with Syngenta. Log 39949.
Root diseases, including take-all, Pythium, Rhizoctonia and common root rots, and Fusarium crown rot, cause $3.5 billion in losses annually to U.S. wheat and barley growers. For most of these diseases, there are no resistant varieties and chemical treatments are not available or perform inconsistently. Modern production practices of reduced tillage and direct seeding, used to control soil erosion, exacerbates the incidence and severity of root diseases. Over the last 30 years, a large amount of research on Rhizoctonia has been conducted in the Pacific Northwest, but little is known about Rhizoctonia in other wheat growing areas of the US. ARS scientists at Pullman, WA in collaboration with scientists at Syngenta are collaborating to survey all major cereal growing areas in the U.S. for Rhizoctonia species. Using their network of field and sales reps, Syngenta is collecting soil samples from all of these areas and shipping them to Pullman. In the fall of 2009 and spring of 2010, 73 soil samples were sent to ARS at Pullman. Rhizoctonia spp. were isolated from all samples and isolates were cultured. DNA was extracted from each isolate and the ITS region was sequenced to identify the species and AG group of the isolate. This study is providing the first national survey of Rhizoctonia on small grains and is greatly increasing the capacity of ARS and Syngenta to respond to outbreaks of this important root pathogen. Accomplishments align with Component 1, Problem Statement 1B and Component 2, Problem Statement 2C of NP 303.