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United States Department of Agriculture

Agricultural Research Service

Title: Introgression of Oat Crown Rust Resistance from Diploid Avena Strigosa and Tetraploid A. Murphyi

Authors
item Rines, Howard
item Porter, Hedera
item Carson, Martin
item Ochocki, Gerald

Submitted to: American Oat Workers Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2006
Publication Date: July 23, 2006
Citation: Rines, H.W., Porter, H.L., Carson, M.L., Ochocki, G.E. 2006. Introgression of oat crown rust resistance from diploid Avena strigosa and tetraploid A. murphyi [abstract]. In: 2006 American Oat Workers' Conference Program Book. 2006 American Oat Workers Conference, July 23-26, 2006, Fargo, North Dakota. p. 28. Available: http://wheat.pw.usda.gov/ggpages/oatnewsletter/v50/AOWC/Oat_Book5.pdf.

Technical Abstract: Accessions of a diploid oat (2n = 2x = 14) Avena strigosa L. (CI 6954SP) and a tetraploid oat (2n = 4x =28) Avena murphyi Ladiz. (P12) were identified as potential new sources of resistance to oat crown rust (Puccinia coronata f. sp. avenae) for introgression into cultivated hexaploid oat (2n = 6x = 42) Avena sativa L. A. strigosa served as the female parent in crosses to A. sativa cv. Black Mesdag and A. murphyi P12. Embryo rescue was required in crosses with Black Mesdag but was unnecessary in crosses with A. murphyi. Viable seed was also produced from crosses between A. sativa cv. Ogle and A. murphyi when Ogle was the female parent. Colchicine doubling was utilized with all F1 plants, allowing for partial self-fertility in the C1 generation. Screening for oat crown rust resistance was conducted using a bulk inoculum collected from the buckthorn nursery on the St. Paul campus. A. strigosa x A. sativa cv. Black Mesdag C1 plants were all susceptible, while both crosses with A. murphyi resulted in an intermediate resistance response. Subsequent backcrosses to the A. strigosa x Black Mesdag and A. strigosa x A. murphyi crosses with rust susceptible A. sativa cv. Ogle have produced progeny segregating for a range of crown rust resistance and susceptibility. Selection in each generation has been for resistant phenotypes. The BC3F1 generation of crosses involving A. strigosa with Ogle as recurrent parent are segregating approximately 1 resistant : 1 susceptible regardless of whether Ogle is the female or male parent. Root tips of plants with moderate to high rust resistance are being analyzed for chromosome number.

Last Modified: 12/27/2014