1
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Sletvold N, Joffard N, Söderquist L. Fine-scale genetic structure in the orchid Gymnadenia conopsea is not associated with local density of flowering plants. AMERICAN JOURNAL OF BOTANY 2024; 111:e16273. [PMID: 38290971 DOI: 10.1002/ajb2.16273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 11/16/2023] [Accepted: 11/16/2023] [Indexed: 02/01/2024]
Abstract
PREMISE Density-dependent pollinator visitation can lead to density-dependent mating patterns and within-population genetic structure. In Gymnadenia conopsea, individuals in low-density patches receive more self pollen than individuals in high-density patches, suggesting higher relatedness at low density. Ongoing fragmentation is also expected to cause more local matings, potentially leading to biparental inbreeding depression. METHODS To evaluate whether relatedness decreases with local density, we analyzed 1315 SNP loci in 113 individuals within two large populations. We quantified within-population genetic structure in one of the populations, recorded potential habitat barriers, and visualized gene flow using estimated effective migration surfaces (EEMS). We further estimated the magnitude of biparental inbreeding depression that would result from matings restricted to within 5 m. RESULTS There was no significant relationship between local density and relatedness in any population. We detected significant fine-scale genetic structure consistent with isolation by distance, with positive kinship coefficients at distances below 10 m. Kinship coefficients were low, and predicted biparental inbreeding depression resulting from matings within the closest 5 m was a modest 1-3%. The EEMS suggested that rocks and bushes may act as barriers to gene flow within a population. CONCLUSIONS The results suggest that increased self-pollen deposition in sparse patches does not necessarily cause higher selfing rates or that inbreeding depression results in low establishment success of inbred individuals. The modest relatedness suggests that biparental inbreeding depression is unlikely to be an immediate problem following fragmentation of large populations. The results further indicate that habitat structure may contribute to governing fine-scale genetic structure in G. conopsea.
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Affiliation(s)
- Nina Sletvold
- Plant Ecology and Evolution, Department of Ecology and Genetics, EBC, Uppsala University, SE-752 36 Uppsala, Sweden
| | - Nina Joffard
- Plant Ecology and Evolution, Department of Ecology and Genetics, EBC, Uppsala University, SE-752 36 Uppsala, Sweden
- UMR 8198 -Evo-Eco-Paleo, University of Lille, Lille, France
| | - Linus Söderquist
- Plant Ecology and Evolution, Department of Ecology and Genetics, EBC, Uppsala University, SE-752 36 Uppsala, Sweden
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2
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Aranda-Rickert A, Torréns J, Yela NI, Brizuela MM, Di Stilio VS. Distance Dependent Contribution of Ants to Pollination but Not Defense in a Dioecious, Ambophilous Gymnosperm. FRONTIERS IN PLANT SCIENCE 2021; 12:722405. [PMID: 34567036 PMCID: PMC8459830 DOI: 10.3389/fpls.2021.722405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
Dioecious plants are obligate outcrossers with separate male and female individuals, which can result in decreased seed set with increasing distance between the sexes. Wind pollination is a common correlate of dioecy, yet combined wind and insect pollination (ambophily) could be advantageous in compensating for decreased pollen flow to isolated females. Dioecious, ambophilous gymnosperms Ephedra (Gnetales) secrete pollination drops (PDs) in female cones that capture airborne pollen and attract ants that feed on them. Plant sugary secretions commonly reward ants in exchange for indirect plant defense against herbivores, and more rarely for pollination. We conducted field experiments to investigate whether ants are pollinators and/or plant defenders of South American Ephedra triandra, and whether their contribution to seed set and seed cone protection varies with distance between female and male plants. We quantified pollen flow in the wind and assessed the effectiveness of ants as pollinators by investigating their relative contribution to seed set, and their visitation rate in female plants at increasing distance from the nearest male. Ants accounted for most insect visits to female cones of E. triandra, where they consumed PDs, and pollen load was larger on bigger ants without reduction in pollen viability. While wind pollination was the main contributor to seed set overall, the relative contribution of ants was distance dependent. Ant contribution to seed set was not significant at shorter distances, yet at the farthest distance from the nearest male (23 m), where 20 times less pollen reached females, ants enhanced seed set by 30% compared to plants depending solely on wind pollination. We found no evidence that ants contribute to plant defense by preventing seed cone damage. Our results suggest that, despite their short-range movements, ants can offset pollen limitation in isolated females of wind-pollinated plants with separate sexes. We propose that ants enhance plant reproductive success via targeted delivery of airborne pollen, through frequent contact with ovule tips while consuming PDs. Our study constitutes the first experimental quantification of distance-dependent contribution of ants to pollination and provides a working hypothesis for ambophily in other dioecious plants lacking pollinator reward in male plants.
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Affiliation(s)
- Adriana Aranda-Rickert
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
| | - Javier Torréns
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
- Universidad Nacional de La Rioja, La Rioja, Argentina
| | - Natalia I. Yela
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
| | - María Magdalena Brizuela
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
- Universidad Nacional de La Rioja, La Rioja, Argentina
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3
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High gene flow through pollen partially compensates spatial limited gene flow by seeds for a Neotropical tree in forest conservation and restoration areas. CONSERV GENET 2021. [DOI: 10.1007/s10592-021-01344-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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4
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Huang K, Huber G, Ritland K, Dunn DW, Li B. Performing parentage analysis for polysomic inheritances based on allelic phenotypes. G3-GENES GENOMES GENETICS 2021; 11:6080682. [PMID: 33585871 PMCID: PMC8022955 DOI: 10.1093/g3journal/jkaa064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 11/09/2020] [Indexed: 11/26/2022]
Abstract
Polyploidy poses several problems for parentage analysis. We present a new polysomic inheritance model for parentage analysis based on genotypes or allelic phenotypes to solve these problems. The effects of five factors are simultaneously accommodated in this model: (1) double-reduction, (2) null alleles, (3) negative amplification, (4) genotyping errors and (5) self-fertilization. To solve genotyping ambiguity (unknown allele dosage), we developed a new method to establish the likelihood formulas for allelic phenotype data and to simultaneously include the effects of our five chosen factors. We then evaluated and compared the performance of our new method with three established methods by using both simulated data and empirical data from the cultivated blueberry (Vaccinium corymbosum). We also developed and compared the performance of two additional estimators to estimate the genotyping error rate and the sample rate. We make our new methods freely available in the software package polygene, at http://github.com/huangkang1987/polygene.
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Affiliation(s)
- Kang Huang
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an 710069, China.,Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada
| | - Gwendolyn Huber
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada
| | - Kermit Ritland
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T1Z4, Canada
| | - Derek W Dunn
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Baoguo Li
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an 710069, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
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Chybicki IJ, Oleksa A, Dering M. Identification of determinants of pollen donor fecundity using the hierarchical neighborhood model. Mol Ecol Resour 2020; 21:781-800. [PMID: 33290637 DOI: 10.1111/1755-0998.13307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 11/24/2020] [Accepted: 12/01/2020] [Indexed: 11/30/2022]
Abstract
Individual differences in male reproductive success drive genetic drift and natural selection, altering genetic variation and phenotypic trait distributions in future generations. Therefore, identifying the determinants of reproductive success is important for understanding the ecology and evolution of plants. Here, based on the spatially explicit mating model (the neighborhood model), we develop a hierarchical probability model that links co-dominant genotypes of offspring and candidate parents with phenotypic determinants of male reproductive success. The model accounts for pollen dispersal, genotyping errors as well as individual variation in selfing, pollen immigration, and differentiation of immigrant pollen pools. Unlike the classic neighborhood model approach, our approach is specially designed to account for excessive variation (overdispersion) in male fecundity. We implemented a Bayesian estimation method (the Windows computer program available at: https://www.ukw.edu.pl/pracownicy/plik/igor_chybicki/1806/) that, among others, allows for selecting phenotypic variables important for male fecundity and assessing the fraction of variance in fecundity (R2 ) explained by selected variables. Simulations showed that our method outperforms both the classic neighborhood model and the two-step approach, where fecundities and the effects of phenotypic variables are estimated separately. The analysis of two data examples showed that in wind-pollinated trees, male fecundity depends on both the amount of produced pollen and the ability to pollen spread. However, despite that the tree size was positively correlated with male fecundity, it explained only a fraction of the total variance in fecundity, indicating the presence of additional factors. Finally, case studies highlighted the importance of accounting for pollen dispersal in the estimation of fecundity determinants.
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Affiliation(s)
- Igor J Chybicki
- Department of Genetics, Kazimierz Wielki University, Bydgoszcz, Poland
| | - Andrzej Oleksa
- Department of Genetics, Kazimierz Wielki University, Bydgoszcz, Poland
| | - Monika Dering
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland.,Department of Silviculture, Poznań University of Life Sciences, Poznań, Poland
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6
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Butcher CL, Rubin BY, Anderson SL, Lewis JD. Pollen dispersal patterns differ among sites for a wind-pollinated species and an insect-pollinated species. AMERICAN JOURNAL OF BOTANY 2020; 107:1504-1517. [PMID: 33108685 DOI: 10.1002/ajb2.1554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
PREMISE Pollen dispersal, the main component of overall plant gene flow, generally decreases with increasing distance from the pollen source, but the pattern of this relationship may differ among sites. Although site-based differences in pollen dispersal may lead to over- or underestimation of gene flow, no studies have investigated pollen dispersal patterns among differing urban site types, despite the incongruent range of habitats in urban areas. METHODS We used paternity assignment to assess pollen dispersal patterns in a wind-pollinated species (waterhemp; Amaranthus tuberculatus) and in an insect-pollinated species (tomato; Solanum lycopersicum) in experimental arrays at four disparate sites (two roof-level sites, two ground-level sites) in the New York (New York, USA) metropolitan area. RESULTS The number of seeds or fruits, a proxy for the number of flowers pollinated, decreased with increasing distance from the pollen donors at all sites for both species. However, the mean number of Amaranthus tuberculatusseeds produced at a given distance differed two-fold among sites, while the slope of the relationship between Solanum lycopersicumfruit production and distance differed by a factor of four among sites. CONCLUSIONS Pollen dispersal patterns may differ substantially among sites, both in the amount of pollen dispersed at a given distance and in the proportional decrease in pollen dispersal with increasing distance, and these effects may act independently. Accordingly, the capacity of plant species to adapt to climate change and other selection pressures may be different from predictions based on pollen dispersal patterns at a single location.
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Affiliation(s)
- Chelsea L Butcher
- Louis Calder Center - Biological Field Station, Fordham University, 31 Whippoorwill Road, Armonk, New York, 10504, USA
- Center for Urban Ecology, Fordham University, 441 East Fordham Road, Bronx, New York, 10458, USA
- Department of Biological Sciences, Fordham University, 441 East Fordham Road, Bronx, New York, 10458, USA
- Department of Mathematics and Natural Sciences, Northwood University, 4000 Whiting Drive, Midland, Michigan, 48640, USA
| | - Berish Y Rubin
- Department of Biological Sciences, Fordham University, 441 East Fordham Road, Bronx, New York, 10458, USA
| | - Sylvia L Anderson
- Department of Biological Sciences, Fordham University, 441 East Fordham Road, Bronx, New York, 10458, USA
| | - James D Lewis
- Louis Calder Center - Biological Field Station, Fordham University, 31 Whippoorwill Road, Armonk, New York, 10504, USA
- Center for Urban Ecology, Fordham University, 441 East Fordham Road, Bronx, New York, 10458, USA
- Department of Biological Sciences, Fordham University, 441 East Fordham Road, Bronx, New York, 10458, USA
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7
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The effects of pollen dispersal and mating pattern on inbreeding depression and hybrid vigor in Balfourodendron riedelianum (Engl.) Engl. (Rutaceae). CONSERV GENET 2020. [DOI: 10.1007/s10592-020-01250-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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8
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Ismail SA, Kokko H. An analysis of mating biases in trees. Mol Ecol 2019; 29:184-198. [PMID: 31755136 PMCID: PMC7003921 DOI: 10.1111/mec.15312] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/01/2019] [Accepted: 11/20/2019] [Indexed: 11/29/2022]
Abstract
Assortative mating is a deviation from random mating based on phenotypic similarity. As it is much better studied in animals than in plants, we investigate for trees whether kinship of realized mating pairs deviates from what is expected from the set of potential mates and use this information to infer mating biases that may result from kin recognition and/or assortative mating. Our analysis covers 20 species of trees for which microsatellite data is available for adult populations (potential mates) as well as seed arrays. We test whether mean relatedness of observed mating pairs deviates from null expectations that only take pollen dispersal distances into account (estimated from the same data set). This allows the identification of elevated as well as reduced kinship among realized mating pairs, indicative of positive and negative assortative mating, respectively. The test is also able to distinguish elevated biparental inbreeding that occurs solely as a result of related pairs growing closer to each other from further assortativeness. Assortative mating in trees appears potentially common but not ubiquitous: nine data sets show mating bias with elevated inbreeding, nine do not deviate significantly from the null expectation, and two show mating bias with reduced inbreeding. While our data sets lack direct information on phenology, our investigation of the phenological literature for each species identifies flowering phenology as a potential driver of positive assortative mating (leading to elevated inbreeding) in trees. Since active kin recognition provides an alternative hypothesis for these patterns, we encourage further investigations on the processes and traits that influence mating patterns in trees.
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Affiliation(s)
- Sascha A Ismail
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Hanna Kokko
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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9
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Grant EL, Conroy GC, Lamont RW, Reddell PW, Wallace HM, Ogbourne SM. Short distance pollen dispersal and low genetic diversity in a subcanopy tropical rainforest tree, Fontainea picrosperma (Euphorbiaceae). Heredity (Edinb) 2019; 123:503-516. [PMID: 31076650 PMCID: PMC6781113 DOI: 10.1038/s41437-019-0231-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/28/2019] [Accepted: 04/24/2019] [Indexed: 11/09/2022] Open
Abstract
Gene flow via pollen movement affects genetic variation in plant populations and is an important consideration in plant domestication. Fontainea picrosperma is a subcanopy rainforest tree that is of commercial interest because it is the source of tigilanol tiglate, a natural product used for the treatment of solid tumors. We identify patterns of pollen-mediated gene flow within natural populations of F. picrosperma and estimate genetic parameters and genetic structure between adult and juvenile groups using microsatellite markers. Our results show pollination events occur over much shorter distances than reported for tropical canopy species. At least 63% of seeds are sired by male trees located within 30 m of the mother. On average, 27% of the local male population contributed to successful reproduction of F. picrosperma with most fathers siring a single seed, however, the contributions to reproduction were uneven. Larger male trees with more flowers had greater reproductive success than those with less flowers (P < 0.05). There were comparatively low levels of genetic variation across the species (HE = 0.405 for adult trees and 0.379 for juveniles) and we found no loss of genetic diversity between adult and juvenile trees. Short distance pollen flow and low genetic diversity is theoretically a prelude to genetic impoverishment, however F. picrosperma has persisted through multiple significant climatic oscillations. Nevertheless, the remaining low genetic diversity is of concern for domestication programs which require maximal genetic diversity to facilitate efficient selective breeding and genetic improvement of this commercially significant species.
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Affiliation(s)
- Elektra L Grant
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Gabriel C Conroy
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Robert W Lamont
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | | | - Helen M Wallace
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Steven M Ogbourne
- GeneCology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia.
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10
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Wang ZF, Liu HL, Dai SP, Cao HL, Wang RJ, Wang ZM. Endangered but genetically stable- Erythrophleum fordii within Feng Shui woodlands in suburbanized villages. Ecol Evol 2019; 9:10950-10963. [PMID: 32523682 PMCID: PMC7277784 DOI: 10.1002/ece3.5513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 07/06/2019] [Accepted: 07/12/2019] [Indexed: 11/21/2022] Open
Abstract
Feng Shui woodlands are naturally or artificially formed green areas in southern China. They are precious for maintaining ecosystem balance in modern semiurban environments. However, they are generally small and geographically isolated from each other, and the status of genetic diversity of the plant species within them has been almost neglected. Therefore, we studied the genetic diversity of the endangered Erythrophleum fordii in eight Feng Shui woodlands (a total of 1,061 individuals) in Guangzhou, a large city in southern China, using microsatellites. For comparison, one population with 33 individuals sampled in a nature reserve was also studied. Although our results indicate that significant demographic declines occurred historically in E. fordii, such declines have not resulted in consistent reductions in genetic variation over generations in Feng Shui populations in the recent past, and the levels of genetic variation in these populations were higher than or comparable to the genetic variation of the population in the nature reserve. In addition, our parentage and paternity analyses indicated widespread and potential long‐distance pollen flow within one Feng Shui woodland, indicating the presence of an unbroken pollination network, which would at least partially alleviate the genetic erosion due to habitat fragmentation and the unequal gene contributions of E. fordii parents to their progenies when favorable recruitment habitats are absent under most of the parent trees. Overall, our results suggest that E. fordii in Feng Shui woodlands may not be driven to extinction in the near future. Nevertheless, uncontrolled fast urban development with a lack of awareness of Feng Shui woodlands will cause the local extinction of E. fordii, which has already happened in some Feng Shui woodlands.
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Affiliation(s)
- Zheng-Feng Wang
- Center of Plant Ecology, Core Botanical Gardens Chinese Academy of Sciences Guangzhou China.,Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden Chinese Academy of Sciences Guangzhou China
| | - Hai-Lin Liu
- Environmental Horticulture Research Institute Guangdong Academy of Agricultural Sciences Guangzhou China.,Key Lab of Ornamental Plant Germplasm Innovation and Utilization Guangzhou China.,University of Chinese Academy of Sciences Beijing China
| | - Se-Ping Dai
- Guangzhou Institute of Forestry and Landscape Architecture Guangzhou China
| | - Hong-Lin Cao
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden Chinese Academy of Sciences Guangzhou China
| | - Rui-Jiang Wang
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden Chinese Academy of Sciences Guangzhou China
| | - Zhang-Ming Wang
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden Chinese Academy of Sciences Guangzhou China
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11
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Stepping stones or stone dead? Fecundity, pollen dispersal and mating patterns of roadside Qualea grandiflora Mart. trees. CONSERV GENET 2019. [DOI: 10.1007/s10592-019-01217-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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12
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Moraes MA, Kubota TYK, Rossini BC, Marino CL, Freitas MLM, Moraes MLT, da Silva AM, Cambuim J, Sebbenn AM. Long-distance pollen and seed dispersal and inbreeding depression in Hymenaea stigonocarpa (Fabaceae: Caesalpinioideae) in the Brazilian savannah. Ecol Evol 2018; 8:7800-7816. [PMID: 30250664 PMCID: PMC6144967 DOI: 10.1002/ece3.4253] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 03/02/2018] [Accepted: 05/14/2018] [Indexed: 02/03/2023] Open
Abstract
Hymenaea stigonocarpa is a neotropical tree that is economically important due to its high-quality wood; however, because it has been exploited extensively, it is currently considered threatened. Microsatellite loci were used to investigate the pollen and seed dispersal, mating patterns, spatial genetic structure (SGS), genetic diversity, and inbreeding depression in H. stigonocarpa adults, juveniles, and open-pollinated seeds, which were sampled from isolated trees in a pasture and trees within a forest fragment in the Brazilian savannah. We found that the species presented a mixed mating system, with population and individual variations in the outcrossing rate (0.53-1.0). The studied populations were not genetically isolated due to pollen and seed flow between the studied populations and between the populations and individuals located outside of the study area. Pollen and seed dispersal occurred over long distances (>8 km); however, the dispersal patterns were isolated by distance, with a high frequency of mating occurring between near-neighbor trees and seeds dispersed near the parent trees. The correlated mating for individual seed trees was higher within than among fruits, indicating that fruits present a high proportion of full-sibs. Genetic diversity and SGS were similar among the populations, but offspring showed evidence of inbreeding, mainly originating from mating among related trees, which suggests inbreeding depression between the seed and adult stages. Selfing resulted in a higher inbreeding depression than mating among relatives, as assessed through survival and height. As the populations are not genetically isolated, both are important targets for in situ conservation to maintain their genetic diversity; for ex situ conservation, seeds can be collected from at least 78 trees in both populations separated by at least 250 m.
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Affiliation(s)
| | | | | | | | | | | | | | - Jose Cambuim
- Faculdade de Engenharia de Ilha Solteira/UNESPIlha SolteiraSPBrazil
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13
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Understanding genetic diversity, spatial genetic structure, and mating system through microsatellite markers for the conservation and sustainable use of Acrocomia aculeata (Jacq.) Lodd. Ex Mart. CONSERV GENET 2018. [DOI: 10.1007/s10592-018-1061-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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14
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Silvestre EDA, Schwarcz KD, Grando C, de Campos JB, Sujii PS, Tambarussi EV, Macrini CMT, Pinheiro JB, Brancalion PHS, Zucchi MI. Mating System and Effective Population Size of the Overexploited Neotropical Tree (Myroxylon peruiferum L.f.) and Their Impact on Seedling Production. J Hered 2017; 109:264-271. [DOI: 10.1093/jhered/esx096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 11/07/2017] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Kaiser Dias Schwarcz
- Agência Paulista de Tecnologia dos Agronegócios, Polo Regional de Desenvolvimento Tecnológico do Centro Sul, Brasil
| | - Carolina Grando
- Universidade Estadual de Campinas, Instituto de Biologia, Brasil
| | | | | | | | | | - José Baldin Pinheiro
- Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Departamento de Genética, Brasil
| | | | - Maria Imaculada Zucchi
- Agência Paulista de Tecnologia dos Agronegócios, Polo Regional de Desenvolvimento Tecnológico do Centro Sul, Brasil
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15
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Genetic conservation of small populations of the endemic tree Swartzia glazioviana (Taub.) Glaz. (Leguminosae) in the Atlantic Forest. CONSERV GENET 2017. [DOI: 10.1007/s10592-017-0962-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Inbreeding depression from selfing and mating between relatives in the Neotropical tree Cariniana legalis Mart. Kuntze. CONSERV GENET 2016. [DOI: 10.1007/s10592-016-0896-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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17
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Persistence of long-distance, insect-mediated pollen movement for a tropical canopy tree species in remnant forest patches in an urban landscape. Heredity (Edinb) 2016; 117:472-480. [PMID: 27703155 DOI: 10.1038/hdy.2016.64] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 07/08/2016] [Accepted: 07/13/2016] [Indexed: 01/25/2023] Open
Abstract
As deforestation and urbanization continue at rapid rates in tropical regions, urban forest patches are essential repositories of biodiversity. However, almost nothing is known about gene flow of forest-dependent tree species in urban landscapes. In this study, we investigated gene flow in the insect-pollinated, wind-dispersed tropical tree Koompassia malaccensis in and among three remnant forest patches in the urbanized landscape of Singapore. We genotyped the vast majority of adults (N=179) and a large number of recruits (N=2103) with 8 highly polymorphic microsatellite markers. Spatial genetic structure of the recruit and adult cohorts was significant, showing routine gene dispersal distances of ~100-400 m. Parentage analysis showed that 97% of recruits were within 100 m of their mother tree, and a high frequency of relatively short-distance pollen dispersal (median ~143-187 m). Despite routine seed and pollen dispersal distances of within a few hundred meters, interpatch gene flow occurred between all patches and was dominated by pollen movement: parentage analysis showed 76 pollen versus 2 seed interpatch dispersal events, and the seedling neighborhood model estimated ~1-6% seed immigration and ~21-46% pollen immigration rates, depending on patch. In addition, the smallest patch (containing five adult K. malaccensis trees) was entirely surrounded by >2.5 km of 'impervious' substrate, yet had the highest proportional pollen and seed immigration estimates of any patch. Hence, contrary to our hypothesis, insect-mediated gene flow persisted across an urban landscape, and several of our results also parallel key findings from insect-pollinated canopy trees sampled in mixed agricultural-forest landscapes.
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Sampson JF, Byrne M, Gibson N, Yates C. Limiting inbreeding in disjunct and isolated populations of a woody shrub. Ecol Evol 2016; 6:5867-80. [PMID: 27547361 PMCID: PMC4983598 DOI: 10.1002/ece3.2322] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 06/27/2016] [Indexed: 02/02/2023] Open
Abstract
Pollen movements and mating patterns are key features that influence population genetic structure. When gene flow is low, small populations are prone to increased genetic drift and inbreeding, but naturally disjunct species may have features that reduce inbreeding and contribute to their persistence despite genetic isolation. Using microsatellite loci, we investigated outcrossing levels, family mating parameters, pollen dispersal, and spatial genetic structure in three populations of Hakea oldfieldii, a fire-sensitive shrub with naturally disjunct, isolated populations prone to reduction in size and extinction following fires. We mapped and genotyped a sample of 102 plants from a large population, and all plants from two smaller populations (28 and 20 individuals), and genotyped 158-210 progeny from each population. We found high outcrossing despite the possibility of geitonogamous pollination, small amounts of biparental inbreeding, a limited number of successful pollen parents within populations, and significant correlated paternity. The number of pollen parents for each seed parent was moderate. There was low but significant spatial genetic structure up to 10 m around plants, but the majority of successful pollen came from outside this area including substantial proportions from distant plants within populations. Seed production varied among seven populations investigated but was not correlated with census population size. We suggest there may be a mechanism to prevent self-pollination in H. oldfieldii and that high outcrossing and pollen dispersal within populations would promote genetic diversity among the relatively small amount of seed stored in the canopy. These features of the mating system would contribute to the persistence of genetically isolated populations prone to fluctuations in size.
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Affiliation(s)
- Jane F Sampson
- Science and Conservation Division Department of Parks and Wildlife Locked Bag 104 Bentley Delivery Centre Perth Western Australia 6983 Australia
| | - Margaret Byrne
- Science and Conservation Division Department of Parks and Wildlife Locked Bag 104 Bentley Delivery Centre Perth Western Australia 6983 Australia
| | - Neil Gibson
- Science and Conservation Division Department of Parks and Wildlife Locked Bag 104 Bentley Delivery Centre Perth Western Australia 6983 Australia
| | - Colin Yates
- Science and Conservation Division Department of Parks and Wildlife Locked Bag 104 Bentley Delivery Centre Perth Western Australia 6983 Australia
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