2008 Annual Report
1a.Objectives (from AD-416)
The objective of the cooperative research between the University of Georgia Research Foundation, Inc. and the USDA Agricultural Research Service is to evaluate and identify sources of resistance to wheat stripe rust and incorporate and identify sources of resistance to wheat stem rust.
1b.Approach (from AD-416)
The University of Georgia Research Foundation, Inc. will obtain, plant, manage, evaluate, and harvest (if needed) uniform nurseries and other germplasm sources of wheat for evaluation to the wheat stripe rust pathogen, Puccinia striiformis and wheat stem rust pathogens, P.graminis. The wheat germplasm will be evaluated for resistance by Georgia Experiment Station personnel using standard evaluation rating scales at one or more locations in the State of Georgia, where stripe rust is known to occur. Data will be put into a standard electronic format and given to the ARS project coordinator. Crosses will be made in coordination with the ARS project coordinator.
3.Progress Report
This project is related to Objective 1 of this in-house project: Identify sources of resistance to foliar fungal pathogens and introgress resistance into adapted wheat. The Uniform Eastern Stripe Rust Nursery and nurseries with elite wheat germplasm from the University of Georgia and other breeding programs in the southeast were grown in 2007-2008 at Griffin and Plains, Georgia for evaluation to wheat stripe rust. The nursery was planted in November at two locations, Griffin and Plains, respectively and inoculated with stripe rust from current races of stripe rust collected in Georgia during the spring of 2007. The races were identified and designated as PST 101 and 102. Twelve inoculated spreader pots of 'AGS 2000' were randomly transplanted in the nursery within the rows. The site was irrigated as needed during the growing season. In early February, infection was detected within the nursery. By mid March the infection was an epidemic. Natural infection was also observed in other nursery plots. Rapid and complete spread of the disease was observed throughout the nursery. Infection types were assessed on the stripe rust expanded 1-to-9 scale where 1-3=resistant, 4-6=intermediate, and 7-9=susceptible. Within the nursery, approximately 25% of the lines were rated as resistant. Both adult and seedling resistance were detected within the germplasm in the nursery. The data was collected, analyzed, and reported. Several lines resistant to stripe rust have the Lr37Yr17 complex. Crosses have been made to determine the genetics of these additional sources of resistance to stripe rust. Principal Investigator confers with the cooperator by phone after planting to assess progress, in late winter to assess nursery inoculation, and in spring to assess disease progress. Principal Investigator visits both nursery locations in the spring to assist in disease severity assessments.
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