Impact of ploidy and pathogen life cycle on resistance durability
The breeding of resistant hosts based on the gene-for-gene interaction is crucial to address epidemics of plant pathogens in agroecosystems. Resistant host deployment strategies are developed and studied worldwide to decrease the probability of resistance breakdown and increase the resistance durabi...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Peer Community In
2021-11-01
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| Series: | Peer Community Journal |
| Online Access: | https://peercommunityjournal.org/articles/10.24072/pcjournal.10/ |
| _version_ | 1827784957548822528 |
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| author | Saubin, Méline De Mita, Stéphane Zhu, Xujia Sudret, Bruno Halkett, Fabien |
| author_facet | Saubin, Méline De Mita, Stéphane Zhu, Xujia Sudret, Bruno Halkett, Fabien |
| author_sort | Saubin, Méline |
| collection | DOAJ |
| description | The breeding of resistant hosts based on the gene-for-gene interaction is crucial to address epidemics of plant pathogens in agroecosystems. Resistant host deployment strategies are developed and studied worldwide to decrease the probability of resistance breakdown and increase the resistance durability in various pathosystems. A major component of deployment strategies is the proportion of resistant hosts in the landscape. However, the impact of this proportion on resistance durability remains unclear for diploid pathogens with complex life cycles. In this study, we modelled pathogen population dynamics and genetic evolution at the virulence locus to assess the impact of the ploidy (haploid or diploid) and the pathogen’s life cycle (with or without host alternation) on resistance durability. Ploidy has a strong impact on evolutionary trajectories, with much greater stochasticity and delayed times of resistance breakdown for diploids. This result emphasises the importance of genetic drift in this system: as the virulent allele is recessive, positive selection on resistant hosts only applies to homozygous (virulent) individuals, which may lead to population collapse at low frequencies of the virulent allele. We also observed differences in the effect of host deployment depending on the pathogen’s life cycle. With host alternation, the probability that the pathogen population collapses strongly increases with the proportion of resistant hosts in the landscape. Therefore, resistance breakdown events occurring at high proportions of resistant hosts frequently amount to evolutionary rescue. Last, life cycles correspond to two selection regimes: without host alternation (soft selection) the resistance breakdown is mainly driven by the migration rate. Conversely, host alternation (hard selection) resembles an all-or-nothing game, with stochastic trajectories caused by the recurrent allele redistributions on the alternate host. |
| first_indexed | 2024-03-11T16:11:18Z |
| format | Article |
| id | doaj.art-88102504f2db44128945e83ecd70288e |
| institution | Directory Open Access Journal |
| issn | 2804-3871 |
| language | English |
| last_indexed | 2024-03-11T16:11:18Z |
| publishDate | 2021-11-01 |
| publisher | Peer Community In |
| record_format | Article |
| series | Peer Community Journal |
| spelling | doaj.art-88102504f2db44128945e83ecd70288e2023-10-24T14:38:25ZengPeer Community InPeer Community Journal2804-38712021-11-01110.24072/pcjournal.1010.24072/pcjournal.10Impact of ploidy and pathogen life cycle on resistance durabilitySaubin, Méline0https://orcid.org/0000-0003-4324-6345De Mita, Stéphane1Zhu, Xujia2Sudret, Bruno3https://orcid.org/0000-0002-9501-7395Halkett, Fabien4https://orcid.org/0000-0001-8856-0501Université de Lorraine, INRAE, IAM, F-54000 Nancy, FranceINRAE, Cirad, IRD, Montpellier SupAgro, Université de Montpellier, PHIM, F-34000 Montpellier, FranceChair of Risk, Safety and Uncertainty Quantification, ETH Zurich, Stefano-Franscini-Platz 5, CH-8093, SwitzerlandChair of Risk, Safety and Uncertainty Quantification, ETH Zurich, Stefano-Franscini-Platz 5, CH-8093, SwitzerlandUniversité de Lorraine, INRAE, IAM, F-54000 Nancy, FranceThe breeding of resistant hosts based on the gene-for-gene interaction is crucial to address epidemics of plant pathogens in agroecosystems. Resistant host deployment strategies are developed and studied worldwide to decrease the probability of resistance breakdown and increase the resistance durability in various pathosystems. A major component of deployment strategies is the proportion of resistant hosts in the landscape. However, the impact of this proportion on resistance durability remains unclear for diploid pathogens with complex life cycles. In this study, we modelled pathogen population dynamics and genetic evolution at the virulence locus to assess the impact of the ploidy (haploid or diploid) and the pathogen’s life cycle (with or without host alternation) on resistance durability. Ploidy has a strong impact on evolutionary trajectories, with much greater stochasticity and delayed times of resistance breakdown for diploids. This result emphasises the importance of genetic drift in this system: as the virulent allele is recessive, positive selection on resistant hosts only applies to homozygous (virulent) individuals, which may lead to population collapse at low frequencies of the virulent allele. We also observed differences in the effect of host deployment depending on the pathogen’s life cycle. With host alternation, the probability that the pathogen population collapses strongly increases with the proportion of resistant hosts in the landscape. Therefore, resistance breakdown events occurring at high proportions of resistant hosts frequently amount to evolutionary rescue. Last, life cycles correspond to two selection regimes: without host alternation (soft selection) the resistance breakdown is mainly driven by the migration rate. Conversely, host alternation (hard selection) resembles an all-or-nothing game, with stochastic trajectories caused by the recurrent allele redistributions on the alternate host.https://peercommunityjournal.org/articles/10.24072/pcjournal.10/ |
| spellingShingle | Saubin, Méline De Mita, Stéphane Zhu, Xujia Sudret, Bruno Halkett, Fabien Impact of ploidy and pathogen life cycle on resistance durability Peer Community Journal |
| title | Impact of ploidy and pathogen life cycle on resistance durability |
| title_full | Impact of ploidy and pathogen life cycle on resistance durability |
| title_fullStr | Impact of ploidy and pathogen life cycle on resistance durability |
| title_full_unstemmed | Impact of ploidy and pathogen life cycle on resistance durability |
| title_short | Impact of ploidy and pathogen life cycle on resistance durability |
| title_sort | impact of ploidy and pathogen life cycle on resistance durability |
| url | https://peercommunityjournal.org/articles/10.24072/pcjournal.10/ |
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