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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #390710
Research Project: Development of High-Yielding, High-Oleic Peanut Cultivars or Germplasm with Tolerance to Biotic and Abiotic Stresses

Location: Crop Genetics and Breeding Research

Title: Development of a greenhouse method to the evaluate peanut resistance to Athelia rolfsii

Author
item TSAI, Y-C - University Of Georgia
item BRENNEMAN, T - University Of Georgia
item Holbrook, Carl - Corley
item CHU, Y - University Of Georgia
item OZIAS-AKINS, P - University Of Georgia
item BERTIOLI, D - University Of Georgia
item LEAL-BERTIOLI, S.C.M. - University Of Georgia

Submitted to: PhytoFrontiers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2022
Publication Date: 3/3/2023
Citation: Tsai, Y., Brenneman, T.B., Holbrook Jr, C.C., Chu, Y., Ozias-Akins, P., Bertioli, D.J., Leal-Bertioli, S. 2023. Development of a greenhouse method to the evaluate peanut resistance to Athelia rolfsii. PhytoFrontiers. 1-27. https://doi.org/10.1094/PHYTOFR-06-22-0069-TA.
DOI: https://doi.org/10.1094/PHYTOFR-06-22-0069-TA

Interpretive Summary: Peanut stem rot (also known as white mold) is one of the most damaging soil borne pathogens for U.S. peanut production. The disease is typically controlled using fungicides and by the adoption of cultivars with moderate resistance. Field evaluation is the main approach for assessing plant resistance, but it is costly and labor-intensive. Reliable methods for in vitro or greenhouse evaluations are desirable. Greenhouse, growth chamber and in vitro methods have been tried to assess resistance, but they generally do not correlate well with field results. In this study, we tested several in vitro and greenhouse methods for evaluation. We devised a method that reliably assesses resistance to stem rot on stem cuttings in the greenhouse. Sixty-day old stem cuttings were transplanted into a cup filled with potting mix and inoculated with white mold. Inoculated cuttings were put in a mist chamber to keep humidity high. Evaluations taken at 3, 5, 7, and 9 days after inoculation (DAI) significantly correlated with field evaluations. This greenhouse assay is a step forward to rapidly screen germplasm for stem rot resistance.

Technical Abstract: Peanut stem rot (also known as white mold), caused by the fungus Athelia rolfsii, is one of the most damaging soil borne pathogens for U.S. peanut production. The disease is typically controlled using fungicides and by the adoption of cultivars with moderate resistance. Field evaluation is the main approach for assessing plant resistance, but it is costly and labor-intensive. Reliable methods for in vitro or greenhouse evaluations are desirable. Greenhouse, growth chamber and in vitro methods have been tried to assess resistance, but they generally do not correlate well with field results. In this study, we tested several in vitro and greenhouse methods for evaluation. We devised a method that reliably assesses resistance to stem rot on stem cuttings in the greenhouse. Sixty-day old stem cuttings were transplanted into a cup filled with potting mix. Cuttings were inoculated with active A. rolfsii mycelial plugs at the base with mycelium directly contacting the stem. Inoculated cuttings were put in a mist chamber to keep humidity high. Evaluations taken at 3, 5, 7, and 9 days after inoculation (DAI) and AUDPC significantly correlated with field evaluations. Despite numerical differences, evaluations done at 7 DAI showed statistically significant differences between genotypes. Overall, this greenhouse assay is a step forward to rapidly screen germplasm for stem rot resistance.