|Boerma, H Roger|
Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/28/2008
Publication Date: 7/26/2008
Citation: Walker, D.R., Nelson, R.L., Hartman, G.L., Buckley, B., Moore, S., Schneider, R.W., Weaver, D., Shipe, E., Mueller, J., Boerma, H. 2008. Identification and characterization of soybean rust resistance in Plant Introductions from the USDA’s soybean germplasm collection [abstract]. 2008 American Phytopathological Society Annual Meeting. July 26-30, 2008. Minneapolis, MN. p. 98:S195.
Technical Abstract: Identification of soybean germplasm accessions with resistance to Phakopsora pachyrhizi is the first step in the development of cultivars with effective and durable resistance to soybean rust. Resistance can involve a hypersensitive response, the development of reddish-brown instead of tan lesions, and/or other host responses that slow the development of the pathogen and the disease. In a 2007 collaboration involving several different institutions, the reactions of 293 to 403 Plant Introductions (PIs) from maturity groups (MGs) 000-X were evaluated at seven locations in five states in the Southeastern U.S.A. Late planting dates and the use of artificial lighting to extend the photoperiod at some sites helped to synchronize plant maturity with the fall rust epidemic. Depending on the location, lines were rated for disease incidence and severity, lesion or uredinia density, and amount of sporulation, often with the help of a microscope. Approximately 85 of the PIs showed high to moderate resistance to rust at two or more locations. The Rpp1 gene conferred immunity to the local isolate at all locations, while Rpp2, Rpp3, and Rpp?(Hyuuga) reduced severity and sporulation at most locations. The reactions of other accessions with unknown resistance genes ranged from apparent immunity to reduced severity and/or sporulation relative to susceptible cultivars with similar maturities. The data obtained from these collaborative evaluations provide North American soybean breeders and pathologists with additional guidance in selecting parents for crosses and in deciding which lines to include in other experiments.