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Dahan-Meir T, Ellis TJ, Mafessoni F, Sela H, Rudich O, Manisterski J, Avivi-Ragolsky N, Raz A, Feldman M, Anikster Y, Nordborg M, Levy AA. 36-year study reveals stability of a wild wheat population across microhabitats. Mol Ecol 2024:e17512. [PMID: 39219267 DOI: 10.1111/mec.17512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 07/02/2024] [Accepted: 08/13/2024] [Indexed: 09/04/2024]
Abstract
Long-term genetic studies of wild populations are very scarce, but are essential for connecting ecological and population genetics models, and for understanding the dynamics of biodiversity. We present a study of a wild wheat population sampled over a 36-year period at high spatial resolution. We genotyped 832 individuals from regular sampling along transects during the course of the experiment. Genotypes were clustered into ecological microhabitats over scales of tens of metres, and this clustering was remarkably stable over the 36 generations of the study. Simulations show that it is difficult to determine whether this spatial and temporal stability reflects extremely limited dispersal or fine-scale local adaptation to ecological parameters. Using a common-garden experiment, we showed that the genotypes found in distinct microhabitats differ phenotypically. Our results provide a rare insight into the population genetics of a natural population over a long monitoring period.
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Affiliation(s)
- Tal Dahan-Meir
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Thomas James Ellis
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Fabrizio Mafessoni
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Hanan Sela
- Institute of Evolution, University of Haifa, Haifa, Israel
- The Institute for Cereal Crops Improvement, Tel-Aviv University, Tel Aviv, Israel
| | - Ori Rudich
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Jacob Manisterski
- The Institute for Cereal Crops Improvement, Tel-Aviv University, Tel Aviv, Israel
| | - Naomi Avivi-Ragolsky
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Amir Raz
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
- Migal, Galilee Technology Center, Kiryat Shmona, Israel
| | - Moshe Feldman
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Yehoshua Anikster
- The Institute for Cereal Crops Improvement, Tel-Aviv University, Tel Aviv, Israel
| | - Magnus Nordborg
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Avraham A Levy
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
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Tisinai SL, Busch JW. Weak response to selection on stigma-anther distance in a primarily selfing population of yellow monkeyflower. Proc Biol Sci 2024; 291:20240586. [PMID: 38889787 DOI: 10.1098/rspb.2024.0586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 05/15/2024] [Indexed: 06/20/2024] Open
Abstract
Stebbins hypothesized that selfing lineages are evolutionary dead ends because they lack adaptive potential. While selfing populations often possess limited nucleotide variability compared with closely related outcrossers, reductions in the genetic variability of quantitative characters remain unclear, especially for key traits determining selfing rates. Yellow monkeyflower (Mimulus guttatus) populations generally outcross and maintain extensive quantitative genetic variation in floral traits. Here, we study the Joy Road population (Bodega Bay, CA, USA) of M. guttatus, where individuals exhibit stigma-anther distances (SAD) typical of primarily selfing monkeyflowers. We show that this population is closely related to nearby conspecifics on the Pacific Coast with a modest 33% reduction in genome-wide variation compared with a more highly outcrossing population. A five-generation artificial selection experiment challenged the hypothesis that the Joy Road population harbours comparatively low evolutionary potential in stigma-anther distance, a critical determinant of selfing rate in Mimulus. Artificial selection generated a weak phenotypic response, with low realized heritabilities (0.020-0.028) falling 84% below those measured for floral characters in more highly outcrossing M. guttatus. These results demonstrate substantial declines in evolutionary potential with a transition toward selfing. Whether these findings explain infrequent reversals to outcrossing or general limits on adaptation in selfers requires further investigation.
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Affiliation(s)
- Shelby L Tisinai
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Jeremiah W Busch
- School of Biological Sciences, Washington State University, Pullman, WA, USA
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Sotola VA, Berg CS, Samuli M, Chen H, Mantel SJ, Beardsley PA, Yuan YW, Sweigart AL, Fishman L. Genomic mechanisms and consequences of diverse postzygotic barriers between monkeyflower species. Genetics 2023; 225:iyad156. [PMID: 37603838 DOI: 10.1093/genetics/iyad156] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/15/2023] [Accepted: 07/18/2023] [Indexed: 08/23/2023] Open
Abstract
The evolution of genomic incompatibilities causing postzygotic barriers to hybridization is a key step in species divergence. Incompatibilities take 2 general forms-structural divergence between chromosomes leading to severe hybrid sterility in F1 hybrids and epistatic interactions between genes causing reduced fitness of hybrid gametes or zygotes (Dobzhansky-Muller incompatibilities). Despite substantial recent progress in understanding the molecular mechanisms and evolutionary origins of both types of incompatibility, how each behaves across multiple generations of hybridization remains relatively unexplored. Here, we use genetic mapping in F2 and recombinant inbred line (RIL) hybrid populations between the phenotypically divergent but naturally hybridizing monkeyflowers Mimulus cardinalis and M. parishii to characterize the genetic basis of hybrid incompatibility and examine its changing effects over multiple generations of experimental hybridization. In F2s, we found severe hybrid pollen inviability (<50% reduction vs parental genotypes) and pseudolinkage caused by a reciprocal translocation between Chromosomes 6 and 7 in the parental species. RILs retained excess heterozygosity around the translocation breakpoints, which caused substantial pollen inviability when interstitial crossovers had not created compatible heterokaryotypic configurations. Strong transmission ratio distortion and interchromosomal linkage disequilibrium in both F2s and RILs identified a novel 2-locus genic incompatibility causing sex-independent gametophytic (haploid) lethality. The latter interaction eliminated 3 of the expected 9 F2 genotypic classes via F1 gamete loss without detectable effects on the pollen number or viability of F2 double heterozygotes. Along with the mapping of numerous milder incompatibilities, these key findings illuminate the complex genetics of plant hybrid breakdown and are an important step toward understanding the genomic consequences of natural hybridization in this model system.
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Affiliation(s)
- V Alex Sotola
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Colette S Berg
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Matthew Samuli
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Hongfei Chen
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Samuel J Mantel
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Paul A Beardsley
- Department of Biological Sciences, California State Polytechnic University, Pomona, CA 91768, USA
| | - Yao-Wu Yuan
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Andrea L Sweigart
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Lila Fishman
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
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Nagasawa K, Fukushima K, Setoguchi H, Katsuyama M, Sakaguchi S. Extreme low pH, not Al 3+ , is a key abiotic stressor for the extremophyte Carex angustisquama (Cyperaceae) in highly acidic solfatara fields. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:551-562. [PMID: 36825368 DOI: 10.1111/plb.13514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 02/20/2023] [Indexed: 05/17/2023]
Abstract
Volcanic acidification creates extreme soil conditions, where rhizotoxicity from extremely low pH (2-3) and high Al3+ strongly inhibit plant growth. C. angustisquama is a dominant extremophyte in highly acidic solfatara fields, where no other vascular plants can survive. Here we investigated the key abiotic stressor determining survival of this extremophyte. Soil analyses and topographic surveys were conducted to examine the effects of low pH and Al3+ , two major abiotic stressors in acidic soils, on the occurrence of C. angustisquama in solfatara fields. Hydroponic culture experiments were also performed to test its growth responses to these stressors. In field surveys, the spatial distribution of soil pH was consistent with vegetation zonation within a solfatara field. In contrast, soil exchangeable Al content was overall low due to strong eluviation. Statistical analysis also supported the significant role of soil pH in determining the distribution of C. angustisquama in a solfatara field. Furthermore, hydroponic culture experiments revealed a higher tolerance of C. angustisquama to low pH than a sister species, especially in the range pH 2-3, corresponding to the pH values of the actual habitats of C. angustisquama. Conversely, no significant interspecific difference was detected in Al3+ tolerance, indicating that both species had high Al3+ tolerance. This study suggests that low pH is a critical abiotic stressor leading to formation of the extremophyte in highly acidic solfatara fields. In contrast, C. angustisquama displayed high tolerance to Al3+ toxicity, probably acquired prior to speciation.
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Affiliation(s)
- K Nagasawa
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - K Fukushima
- The Center for Ecological Research, Kyoto University, Otsu, Shiga, Japan
| | - H Setoguchi
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - M Katsuyama
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - S Sakaguchi
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
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