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Chen YJ, Pandey S, Catto M, Leal-Bertioli S, Abney MR, Bag S, Hopkins M, Culbreath A, Srinivasan R. Evaluation of Wild Peanut Species and Their Allotetraploids for Resistance against Thrips and Thrips-Transmitted Tomato Spotted Wilt Orthotospovirus (TSWV). Pathogens 2023; 12:1102. [PMID: 37764910 PMCID: PMC10536083 DOI: 10.3390/pathogens12091102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
Thrips-transmitted tomato spotted wilt orthotospovirus (TSWV) causes spotted wilt disease in peanut (Arachis hypogaea L.) and limits yield. Breeding programs have been developing TSWV-resistant cultivars, but availability of sources of resistance against TSWV in cultivated germplasm is extremely limited. Diploid wild Arachis species can serve as important sources of resistance, and despite ploidy barriers (cultivated peanut is tetraploid), their usage in breeding programs is now possible because of the knowledge and development of induced interspecific allotetraploid hybrids. This study screened 10 wild diploid Arachis and six induced allotetraploid genotypes via thrips-mediated TSWV transmission assays and thrips' feeding assays in the greenhouse. Three parameters were evaluated: percent TSWV infection, virus accumulation, and temporal severity of thrips feeding injury. Results indicated that the diploid A. stenosperma accession V10309 and its derivative-induced allotetraploid ValSten1 had the lowest TSWV infection incidences among the evaluated genotypes. Allotetraploid BatDur1 had the lowest thrips-inflicted damage at each week post thrips release, while diploid A. batizocoi accession K9484 and A. duranensis accession V14167 had reduced feeding damage one week post thrips release, and diploids A. valida accession GK30011 and A. batizocoi had reduced feeding damage three weeks post thrips releasethan the others. Overall, plausible TSWV resistance in diploid species and their allotetraploid hybrids was characterized by reduced percent TSWV infection, virus accumulation, and feeding severity. Furthermore, a few diploids and tetraploid hybrids displayed antibiosis against thrips. These results document evidence for resistance against TSWV and thrips in wild diploid Arachis species and peanut-compatible-induced allotetraploids.
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Affiliation(s)
- Yi-Ju Chen
- Department of Entomology, University of Georgia, Griffin, GA 30223, USA; (Y.-J.C.); (S.P.)
| | - Sudeep Pandey
- Department of Entomology, University of Georgia, Griffin, GA 30223, USA; (Y.-J.C.); (S.P.)
| | - Michael Catto
- Department of Entomology, University of Georgia, Athens, GA 30602, USA;
| | - Soraya Leal-Bertioli
- Department of Plant Pathology, Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA 30602, USA;
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA 30602, USA;
| | - Mark R. Abney
- Department of Entomology, University of Georgia, Tifton, GA 31794, USA;
| | - Sudeep Bag
- Department of Plant Pathology, University of Georgia, Tifton, GA 31793, USA; (S.B.); (A.C.)
| | - Mark Hopkins
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA 30602, USA;
| | - Albert Culbreath
- Department of Plant Pathology, University of Georgia, Tifton, GA 31793, USA; (S.B.); (A.C.)
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Lai PC, Abney MR, Bag S, Culbreath AK, Srinivasan R. Impact of Host Resistance to Tomato Spotted Wilt Orthotospovirus in Peanut Cultivars on Virus Population Genetics and Thrips Fitness. Pathogens 2021; 10:1418. [PMID: 34832574 DOI: 10.3390/pathogens10111418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/28/2021] [Accepted: 10/29/2021] [Indexed: 11/25/2022] Open
Abstract
Thrips-transmitted tomato spotted wilt orthotospovirus (TSWV) is a major constraint to peanut production in the southeastern United States. Peanut cultivars with resistance to TSWV have been widely used for over twenty years. Intensive usage of resistant cultivars has raised concerns about possible selection pressure against TSWV and a likelihood of resistance breakdown. Population genetics of TSWV isolates collected from cultivars with varying levels of TSWV resistance was investigated using five TSWV genes. Phylogenetic trees of genes did not indicate host resistance-based clustering of TSWV isolates. Genetic variation in TSWV isolates and neutrality tests suggested recent population expansion. Mutation and purifying selection seem to be the major forces driving TSWV evolution. Positive selection was found in N and RdRp genes but was not influenced by TSWV resistance. Population differentiation occurred between isolates collected from 1998 and 2010 and from 2016 to 2019 but not between isolates from susceptible and resistant cultivars. Evaluated TSWV-resistant cultivars differed, albeit not substantially, in their susceptibility to thrips. Thrips oviposition was reduced, and development was delayed in some cultivars. Overall, no evidence was found to support exertion of selection pressure on TSWV by host resistance in peanut cultivars, and some cultivars differentially affected thrips fitness than others.
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