Screening U.S. peanut germplasm for resistance to peanut smut

Authors: Chamberlin, Kelly; Bennett, Rebecca; BALDESSARI, JORGE - National Institute Of Agricultural Technology(INTA); Holbrook, Carl - Corley; Tallury, Shyamalrau - Shyam; OZAIS-AKINS, P - University Of Georgia

Submitted to: International Conference on Advances in Arachis through Genomics and Biotechnology
Publication Type: Abstract Only
Publication Acceptance Date: 8/20/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: Proactive breeding measures are being taken to develop peanut smut resistant cultivars suitable for production in the U.S. This report summarizes the results from year 1 of testing U.S. germplasm for resistance to this disease to identify potential sources of resistance that can be used as breeding material by U.S. breeding programs.

Technical Abstract: Peanut smut, caused by Thecaphora frezzii, was first reported in Brazil, but has since spread to other countries including Argentina where it has become established and is now found in 100% of the country's peanut growing regions. Disease severity varies with location but yield reductions as high as 51% have been reported. Although peanut smut is not currently found in the U.S., immediate proactive measures will ensure that the industry will not be threatened should this disease reach the U.S. The first step in breeding efforts for peanut smut is to identify sources of resistance. Therefore, the objective of this study was to identify sources of resistance to T. frezzii that can be used to incorporate smut resistance into cultivars optimized for key areas of U.S. peanut production. In 2017, 106 genotypes, including mini-core accessions from the USDA Peanut Germplasm collection and a selection of U.S. elite breeding lines and cultivars, were planted in a test plot with high levels of T. frezzii inoculum near the town of General Deheza (Córdoba Province). Plots were arranged in an augmented grid design with three replicates and were maintained for weeds and other diseases throughout the growing season. Upon harvest, pods were air dried and opened by hand to rate for the presence or absence of T. frezzii. For screening purposes, entries were retained for further testing if they scored 10% or less disease incidence. Of the 106 test entries, 35 potential sources of peanut smut resistance were identified. Thirteen entries had 0% disease incidence, 9 entries had between 0 and 5% disease incidence, and 13 entries had between 5% and 10% disease incidence. Seventy-one (71) of the entries tested had greater than 10% disease incidence and have been eliminated from future testing. Entries demonstrating strong resistance over multiple years can be used to incorporate peanut smut resistance into cultivars suitable for U.S. production areas.