Location: National Peanut Research LaboratoryTitle: Evaluation of leaf spot resistance in wild arachis species of section arachis
|Arias De Ares, Renee|
|Sorensen, Ronald - Ron|
|Tallury, Shyamalrau - Shyam|
|STALKER, THOMAS - North Carolina State University|
Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/2021
Publication Date: 8/25/2021
Citation: Massa, A.N., Arias De Ares, R.S., Sorensen, R.B., Sobolev, V., Tallury, S.P., Stalker, T.S., Lamb, M.C. 2021. Evaluation of leaf spot resistance in wild arachis species of section arachis. Peanut Science. 48(2):68-75. https://doi.org/10.3146/PS20-25.1.
Interpretive Summary: Early leaf spot (ELS) and late leaf spot (LLS) are foliar fungal diseases of peanut responsible for significant yield losses worldwide. Wild peanut species, including the progenitors of cultivated peanut are potential sources of resistance to leaf spots. In this study, we screened 78 accessions representing 15 species of wild species from the USDA peanut germplasm collection to identify new sources of resistance. Statistically significant differences were observed within and among species. We report new sources of resistance to leaf spot diseases, which have been evaluated in an environment with high inoculum pressure. The presence of both ELS and LLS enabled the selection of resistant germplasm for further introgression and pre-breeding.
Technical Abstract: Wild diploid Arachis species are potential sources of resistance to early (ELS) and late (LLS) leaf spot diseases caused by Passalora arachidicola (syn. Cercospora arachidicola Hori), and Nothopassalora personata (syn. Cercosporidium personatum (Berk. & Curt.) Deighton], respectively. Within section Arachis, limited information is available on the extent of genetic variation for resistance to these fungal pathogens. In this study, a collection of 78 accessions representing 15 wild species of Arachis section Arachis from the U.S peanut germplasm collection was evaluated for resistance to these fungal pathogens. Screening was conducted under field (natural inoculum) conditions at the NPRL in Dawson, Georgia, during 2017 and 2018. Accessions differed significantly (P < 0.01) for all three disease variables evaluated, which included final defoliation rating, ELS lesion counts, and LLS lesion counts. Relatively high levels of resistance were identified for both diseases, with LLS being the predominant pathogen during the two years of evaluation. We report new sources of resistance to leaf spot diseases, which have been evaluated in an environment with high inoculum pressure. The presence of both ELS and LLS enabled the selection of resistant germplasm for further introgression and pre-breeding.