|Harting, Angela - Angie|
|SIMPSON, CHARLES - Texas A&M Agrilife|
|Tallury, Shyamalrau - Shyam|
|PICKERING, AUSTIN - Oklahoma State University|
|WANG, NING - Oklahoma State University|
|DUNNE, JEFF - North Carolina State University|
Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2021
Publication Date: 2/3/2021
Citation: Bennett, R., Harting, A.D., Simpson, C.E., Tallury, S.P., Pickering, A.B., Wang, N., Dunne, J.C. 2021. A note on a Greenhouse evaluation of wild Arachis species for resistance to Athelia rolfsii. Peanut Science. 48(1):40-48. https://doi.org/10.3146/PS20-21.1.
Interpretive Summary: One of the most damaging diseases of cultivated peanut is the soilborne disease known regionally as southern blight, stem rot, and white mold. Because cultivated peanut has little genetic diversity, close wild relatives of peanut may have new sources of disease resistance that may be transferred to cultivated peanut using traditional breeding methods. Therefore, we evaluated 18 accessions of wild peanuts, representing 15 species, that are maintained by the U.S. National Plant Germplasm System for resistance to southern blight. Evaluations were conducted in a greenhouse using rooted cuttings inoculated with fungal mycelium. Some wild accessions were highly susceptible to southern blight, but four accessions of three wild species (Arachis microsperma, A. diogoi, and A. cardenasii) appeared to be resistant. These accessions may be useful to peanut geneticists seeking new sources of resistance to Athelia rolfsii.
Technical Abstract: Athelia rolfsii (Curzi) C.C. Tu & Kimbr. is the one of the most damaging pathogens of cultivated peanut, causing the soilborne disease known regionally as white mold, stem rot or southern blight. Because the genetic base for cultivated peanut is narrow, wild Arachis species may possess novel sources of disease resistance. We evaluated 18 accessions representing 15 Arachis species (batizocoi, benensis, cardenasii, correntina, cruziana, diogoi, duranensis, herzogii, hoehnei, kempff-mercadoi, kuhlmannii, microsperma, monticola, simpsonii, williamsii) in the greenhouse for resistance to Athelia rolfsii. Inoculations were conducted on intact plants propagated from rooted cuttings inoculated with mycelial plugs, and lesion length and mycelial growth were measured at 4, 6, 10, and 12 days after inoculation. For lesion length, Arachis batizocoi (PI 468326 and PI 468327), A. kuhlmannii PI 468159 were the most susceptible entries with a mean lesion length >50 mm at 12 days after inoculation. Arachis microsperma (PI 666096 and PI 674407) and A. diogoi (PI 468354) had the shortest lesions with mean lengths <16 mm at 12 days after inoculation. Arachis cruziana PI 476003 and the two A. batizocoi PIs had the highest mean area under the disease progress curves (AUDPCs), and the lowest AUDPC was obtained from the A. microsperma PI 674407. Mycelial growth was correlated with lesion length in most species except A. monticola PI 497260. These results may be useful to peanut geneticists seeking additional sources of resistance to Athelia rolfsii.