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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Peanut and Small Grains Research Unit » Research » Publications at this Location » Publication #368121
Research Project: Genetic Improvement of Peanut for Production in the Southwest United States Region

Location: Peanut and Small Grains Research Unit

Title: Resistance to Athelia rolfsii and web blotch in the U.S. Mini-core Collection

Author
item Bennett, Rebecca
item Chamberlin, Kelly

Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/8/2020
Publication Date: 7/1/2021
Citation: Bennett, R.S., Chamberlin, K.D. 2021. Resistance to Athelia rolfsii and web blotch in the U.S. Mini-core Collection. Peanut Science. 47(1):17-24. https://doi.org/10.3146/PS19-18.1.
DOI: https://doi.org/10.3146/PS19-18.1

Interpretive Summary: One of the most serious diseases of peanut around the world is southern blight, which is also called southern stem rot, stem rot, and white mold in different regions. While the U.S. peanut germplasm collection has been evaluated for resistance to several diseases, there has been no work evaluating the collection for southern blight resistance. Therefore, 71 of the 112 accessions comprising the U.S. peanut mini-core collection were evaluated in the field in Oklahoma for resistance to southern blight in 2016 to 2018. Four germplasm accessions appeared highly resistant to southern blight in 2018 and 2017, when environmental conditions were most favorable for disease. Ratings for web blotch, a yield-limiting disease in some peanut production areas, were also taken in 2017 and 2018, when outbreaks of this foliar disease occurred. Five mini-core accessions exhibited high resistance to web blotch. These results will be useful to breeders seeking additional sources of resistance to southern blight and web blotch for their peanut breeding programs.

Technical Abstract: Athelia rolfsii (=Sclerotium rolfsii) is a soilborne fungus that causes the disease commonly known as southern blight, southern stem rot, stem rot, and white mold. Despite the fact that A. rolfsii is one of the most destructive pathogens of peanut, the U.S. germplasm collection has not been evaluated for resistance to this pathogen. Therefore, 71 of the 112 accessions comprising the U.S. peanut mini-core collection were evaluated in the field in Oklahoma for resistance to southern blight in 2016 to 2018. Moderate to low levels of southern blight were observed, but four accessions—CC125, CC208, CC559, and CC650—had low levels of disease in 2017 and 2018, the most favorable years for A. rolfsii. Ratings for web blotch, a yield-limiting disease in some peanut production areas, were also taken in 2017 and 2018, when outbreaks of this foliar disease occurred. Five entries—CC287, CC155, CC149, CC812, and CC559—had between 10% and 20% disease in 2018, a year when over half of the mini-core accessions exhibited between 50% and 93% disease. Because cultivated peanut in the U.S. has a narrow genetic base, these results will be useful to breeders seeking additional sources of resistance to A. rolfsii and web blotch.