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Hood ME, Nelson S, Cho J, Launi M, Antonovics J, Bruns EL. Quantitative disease resistance in wild Silene vulgaris to its endemic pathogen Microbotryum silenes-inflatae. Ecol Evol 2023; 13:e10797. [PMID: 38125956 PMCID: PMC10731388 DOI: 10.1002/ece3.10797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 12/23/2023] Open
Abstract
The evolution of disease resistances is an expected feature of plant-pathogen systems, but whether the genetics of this trait most often produces qualitative or quantitative phenotypic variation is a significant gap in our understanding of natural populations. These two forms of resistance variation are often associated with differences in number of underlying loci, the specificities of host-pathogen coevolution, as well as contrasting mechanisms of preventing or slowing the infection process. Anther-smut disease is a commonly studied model for disease of wild species, where infection has severe fitness impacts, and prior studies have suggested resistance variation in several host species. However, because the outcome of exposing the individual host to this pathogen is binary (healthy or diseased), resistance has been previously measured at the family level, as the proportion of siblings that become diseased. This leaves uncertain whether among-family variation reflects contrasting ratios of segregating discrete phenotypes or continuous trait variation among individuals. In the host Silene vulgaris, plants were replicated by vegetative propagation in order to quantify the infection rates of the individual genotype with the endemic anther-smut pathogen, Microbotryum silenes-inflatae. The variance among field-collected families for disease resistance was significant, while there was unimodal continuous variation in resistance among genotypes. Using crosses between genotypes within ranked resistance quartiles, the offspring infection rate was predicted by the parental resistance values. While the potential remains in this system for resistance genes having major effects, as there were suggestions of such qualitative resistance in a prior study, here the quantitative disease resistance to the endemic anther-smut pathogen is indicated for S. vulgaris. The variation in natural populations and strong heritability of the trait, combined with severe fitness consequences of anther-smut disease, suggests that resistance in these host populations is highly capable of responding to disease-induced selection.
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Affiliation(s)
| | - Sydney Nelson
- Department of BiologyAmherst CollegeAmherstMassachusettsUSA
| | - Jae‐Hoon Cho
- Department of BiologyAmherst CollegeAmherstMassachusettsUSA
| | - Michelle Launi
- Department of BiologyAmherst CollegeAmherstMassachusettsUSA
| | - Janis Antonovics
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Emily L. Bruns
- Department of BiologyUniversity of Maryland at College ParkCollege ParkMarylandUSA
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Bobadilla LK, Baek Y, Tranel PJ. Comparative transcriptomic analysis of male and females in the dioecious weeds Amaranthus palmeri and Amaranthus tuberculatus. BMC PLANT BIOLOGY 2023; 23:339. [PMID: 37365527 DOI: 10.1186/s12870-023-04286-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/16/2023] [Indexed: 06/28/2023]
Abstract
BACKGROUND Waterhemp (Amaranthus tuberculatus (Moq.) Sauer) and Palmer amaranth (Amaranthus palmeri S. Wats.) are two dioecious and important weed species in the world that can rapidly evolve herbicide-resistance traits. Understanding these two species' dioecious and sex-determination mechanisms could open opportunities for new tools to control them. This study aims to identify the differential expression patterns between males and females in A. tuberculatus and A. palmeri. Multiple analyses, including differential expression, co-expression, and promoter analyses, used RNA-seq data from multiple tissue types to identify putative essential genes for sex determination in both dioecious species. RESULTS Genes were identified as potential key players for sex determination in A. palmeri. Genes PPR247, WEX, and ACD6 were differentially expressed between the sexes and located at scaffold 20 within or near the male-specific Y (MSY) region. Multiple genes involved with flower development were co-expressed with these three genes. For A. tuberculatus, no differentially expressed gene was identified within the MSY region; however, multiple autosomal class B and C genes were identified as differentially expressed and possible candidate genes. CONCLUSIONS This is the first study comparing the global expression profile between males and females in dioecious weedy Amaranthus species. Results narrow down putative essential genes for sex-determination in A. palmeri and A. tuberculatus and also strengthen the hypothesis of two different evolutionary events for dioecy within the genus.
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Affiliation(s)
- Lucas K Bobadilla
- Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | - Yousoon Baek
- Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | - Patrick J Tranel
- Department of Crop Sciences, University of Illinois, Urbana, IL, USA.
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de Jesus Aguilar-Aguilar M, Cristobal-Pérez EJ, Lobo J, Fuchs EJ, Oyama K, Martén-Rodríguez S, Herrerías-Diego Y, Quesada M. Gone with the wind: Negative genetic and progeny fitness consequences of habitat fragmentation in the wind pollinated dioecious tree Brosimum alicastrum. AMERICAN JOURNAL OF BOTANY 2023; 110:e16157. [PMID: 36934453 DOI: 10.1002/ajb2.16157] [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: 06/28/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 05/11/2023]
Abstract
PREMISE Habitat fragmentation negatively affects population size and mating patterns that directly affect progeny fitness and genetic diversity; however, little is known about the effects of habitat fragmentation on dioecious, wind pollinated trees. We assessed the effects of habitat fragmentation on population sex ratios, genetic diversity, gene flow, mating patterns, and early progeny vigor in the tropical dioecious tree, Brosimum alicastrum. METHODS We conducted our study in three continuous and three fragmented forest sites in a Mexican tropical dry forest. We used eight microsatellite loci to characterize the genetic diversity, gene flow via pollen distances, and mean relatedness of progeny. We compared early progeny vigor parameters of seedlings growing under greenhouse conditions. RESULTS Sex ratios did not deviate from 1:1 between habitat conditions except for one population in a fragmented habitat, which was female biased. The genetic diversity of adult trees and their offspring was similar in both habitat conditions. Pollen gene flow distances were similar across habitat types; however, paternity correlations were greater in fragmented than in continuous habitats. Germination rates did not differ between habitat conditions; however, progeny from fragmented habitats produced fewer leaves and had a lower foliar area, total height, and total dry biomass than progeny from continuous habitats. CONCLUSIONS Changes in mating patterns because of habitat fragmentation have negative effects on early progeny vigor. We conclude that negative habitat fragmentation effects on mating patterns and early progeny vigor may be a serious threat to the long-term persistence of tropical dioecious trees.
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Affiliation(s)
- Maria de Jesus Aguilar-Aguilar
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
| | - E Jacob Cristobal-Pérez
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
| | - Jorge Lobo
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Eric J Fuchs
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Ken Oyama
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
| | - Silvana Martén-Rodríguez
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
| | - Yvonne Herrerías-Diego
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México
| | - Mauricio Quesada
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Nacional de Análisis y Síntesis Ecológica, Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México
- Laboratorio Binacional de Análisis y Síntesis Ecológica, UNAM-UCR, México, Costa Rica
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Broz AK, Waneka G, Wu Z, Fernandes Gyorfy M, Sloan DB. Detecting de novo mitochondrial mutations in angiosperms with highly divergent evolutionary rates. Genetics 2021; 218:iyab039. [PMID: 33704433 PMCID: PMC8128415 DOI: 10.1093/genetics/iyab039] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/04/2021] [Indexed: 02/06/2023] Open
Abstract
Although plant mitochondrial genomes typically show low rates of sequence evolution, levels of divergence in certain angiosperm lineages suggest anomalously high mitochondrial mutation rates. However, de novo mutations have never been directly analyzed in such lineages. Recent advances in high-fidelity DNA sequencing technologies have enabled detection of mitochondrial mutations when still present at low heteroplasmic frequencies. To date, these approaches have only been performed on a single plant species (Arabidopsis thaliana). Here, we apply a high-fidelity technique (Duplex Sequencing) to multiple angiosperms from the genus Silene, which exhibits extreme heterogeneity in rates of mitochondrial sequence evolution among close relatives. Consistent with phylogenetic evidence, we found that Silene latifolia maintains low mitochondrial variant frequencies that are comparable with previous measurements in Arabidopsis. Silene noctiflora also exhibited low variant frequencies despite high levels of historical sequence divergence, which supports other lines of evidence that this species has reverted to lower mitochondrial mutation rates after a past episode of acceleration. In contrast, S. conica showed much higher variant frequencies in mitochondrial (but not in plastid) DNA, consistent with an ongoing bout of elevated mitochondrial mutation rates. Moreover, we found an altered mutational spectrum in S. conica heavily biased towards AT→GC transitions. We also observed an unusually low number of mitochondrial genome copies per cell in S. conica, potentially pointing to reduced opportunities for homologous recombination to accurately repair mismatches in this species. Overall, these results suggest that historical fluctuations in mutation rates are driving extreme variation in rates of plant mitochondrial sequence evolution.
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Affiliation(s)
- Amanda K Broz
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Gus Waneka
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Zhiqiang Wu
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, 518120 Shenzhen, China
| | | | - Daniel B Sloan
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
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Schrieber K, Paul SC, Höche LV, Salas AC, Didszun R, Mößnang J, Müller C, Erfmeier A, Eilers EJ. Inbreeding in a dioecious plant has sex- and population origin-specific effects on its interactions with pollinators. eLife 2021; 10:65610. [PMID: 33988502 PMCID: PMC8159375 DOI: 10.7554/elife.65610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 05/09/2021] [Indexed: 12/19/2022] Open
Abstract
We study the effects of inbreeding in a dioecious plant on its interaction with pollinating insects and test whether the magnitude of such effects is shaped by plant individual sex and the evolutionary histories of plant populations. We recorded spatial, scent, colour, and rewarding flower traits as well as pollinator visitation rates in experimentally inbred and outbred, male and female Silene latifolia plants from European and North American populations differing in their evolutionary histories. We found that inbreeding specifically impairs spatial flower traits and floral scent. Our results support that sex-specific selection and gene expression may have partially magnified these inbreeding costs for females, and that divergent evolutionary histories altered the genetic architecture underlying inbreeding effects across population origins. Moreover, the results indicate that inbreeding effects on floral scent may have a huge potential to disrupt interactions among plants and nocturnal moth pollinators, which are mediated by elaborate chemical communication.
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Affiliation(s)
- Karin Schrieber
- Kiel University, Institute for Ecosystem Research, Geobotany, Kiel, Germany
| | - Sarah Catherine Paul
- Bielefeld University, Faculty of Biology, Department of Chemical Ecology, Bielefeld, Germany
| | - Levke Valena Höche
- Kiel University, Institute for Ecosystem Research, Geobotany, Kiel, Germany
| | | | - Rabi Didszun
- Kiel University, Institute for Ecosystem Research, Geobotany, Kiel, Germany
| | - Jakob Mößnang
- Kiel University, Institute for Ecosystem Research, Geobotany, Kiel, Germany
| | - Caroline Müller
- Bielefeld University, Faculty of Biology, Department of Chemical Ecology, Bielefeld, Germany
| | - Alexandra Erfmeier
- Kiel University, Institute for Ecosystem Research, Geobotany, Kiel, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
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Punja ZK, Holmes JE. Hermaphroditism in Marijuana ( Cannabis sativa L.) Inflorescences - Impact on Floral Morphology, Seed Formation, Progeny Sex Ratios, and Genetic Variation. FRONTIERS IN PLANT SCIENCE 2020; 11:718. [PMID: 32670310 PMCID: PMC7329997 DOI: 10.3389/fpls.2020.00718] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/06/2020] [Indexed: 05/26/2023]
Abstract
Cannabis sativa L. (hemp, marijuana) produces male and female inflorescences on different plants (dioecious) and therefore the plants are obligatory out-crossers. In commercial production, marijuana plants are all genetically female; male plants are destroyed as seed formation reduces flower quality. Spontaneously occurring hermaphroditic inflorescences, in which pistillate flowers are accompanied by formation of anthers, leads to undesired seed formation; the mechanism for this is poorly understood. We studied hermaphroditism in several marijuana strains with three objectives: (i) to compare the morphological features of this unique phenotype with normal male flowers; (ii) to assess pollen and seed viability from hermaphroditic flowers; and (iii) to assess the effect of hermaphroditism on progeny male:female (sex) ratios and on genetic variation using molecular methods. The morphological features of anthers, pollen production and germination in hermaphroditic flowers and in staminate inflorescences on male plants were compared using light and scanning electron microscopy. Seeds produced on hermaphroditic plants and seeds derived from cross-fertilization were germinated and seedlings were compared for gender ratios using a PCR-based assay as well as for the extent of genetic variation using six ISSR primers. Nei's index of gene diversity and Shannon's Information index were compared for these two populations. The morphology of anthers and pollen formation in hermaphroditic inflorescences was similar to that in staminate flowers. Seedlings from hermaphroditic seeds, and anther tissues, showed a female genetic composition while seedlings derived from cross-fertilized seeds showed a 1:1 male:female sex expression ratio. Uniquely, hermaphroditic inflorescences produced seeds which gave rise only to genetically female plants. In PCR assays, a 540 bp size fragment was present in male and female plants, while a 390 bp band was uniquely associated with male plants. Sequence analysis of these fragments revealed the presence of Copia-like retrotransposons within the C. sativa genome which may be associated with the expression of male or female phenotype. In ISSR analysis, the percentage of polymorphic loci ranged from 44 to 72% in hermaphroditic and cross-fertilized populations. Nei's index of gene diversity and Shannon's Information index were not statistically different for both populations. The extent of genetic variation after one generation of selfing in the progeny from hermaphroditic seed is similar to that in progeny from cross-fertilized seeds.
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Lee SR, Park HS, Kim BY, Lee JH, Fan Q, Gaskin JF, Kim YD. An unexpected genetic diversity pattern and a complex demographic history of a rare medicinal herb, Chinese asparagus (Asparagus cochinchinensis) in Korea. Sci Rep 2019; 9:9757. [PMID: 31278330 PMCID: PMC6611897 DOI: 10.1038/s41598-019-46275-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 06/25/2019] [Indexed: 11/09/2022] Open
Abstract
Range-wide population studies of wide spread species are often associated with complex diversity patterns resulting from genetically divergent evolutionary significant units (ESUs). The compound evolutionary history creating such a pattern of diversity can be inferred through molecular analyses. Asparagus cochinchinensis, a medicinally important perennial herb, is in decline due to overharvesting in Korea. Eight A. cochinchinensis populations in Korea and three populations from neighboring countries (China, Japan and Taiwan) were examined using nine nuclear microsatellite loci and three chloroplast microsatellite loci to characterize molecular diversity patterns. The average within-population diversity was limited likely due to long-term bottlenecks observed in all eight populations. High pairwise FST values indicated that the populations have largely diverged, but the divergences were not correlated with geographic distances. Clustering analyses revealed a highly complex spatial structure pattern associated with two ESUs. Approximate Bayesian Computation (ABC) suggests that the two ESUs split about 21,000 BP were independently introduced to Korea approximately 1,800 years ago, and admixed in secondary contact zones. The two ESUs found in our study may have different habitat preferences and growth conditions, implying that the two genetically divergent groups should be considered not only for conservation and management but also for breeding programs in agricultural areas.
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Affiliation(s)
- Soo-Rang Lee
- Multidisciplinary Genome Institute, Hallym University, Chuncheon, 24252, South Korea
| | - Han-Sol Park
- National Institute of Biological Resources, Incheon, 22689, South Korea
| | - Bo-Yun Kim
- Multidisciplinary Genome Institute, Hallym University, Chuncheon, 24252, South Korea
| | - Jung-Hoon Lee
- Department of Life Sciences, Hallym University, Chuncheon, 24252, South Korea
| | - Qiang Fan
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, Sun Yat-sen University, Guangzhou, 510275, China
| | - John F Gaskin
- USDA-ARS, 1500 North Central Avenue, Sidney, Montana, 59270, USA
| | - Young-Dong Kim
- Department of Life Sciences, Hallym University, Chuncheon, 24252, South Korea.
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Feurtey A, Gladieux P, Hood ME, Snirc A, Cornille A, Rosenthal L, Giraud T. Strong phylogeographic co-structure between the anther-smut fungus and its white campion host. THE NEW PHYTOLOGIST 2016; 212:668-679. [PMID: 27500396 DOI: 10.1111/nph.14125] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/18/2016] [Indexed: 06/06/2023]
Abstract
Although congruence between host and pathogen phylogenies has been extensively investigated, the congruence between host and pathogen genetic structures at the within-species level has received little attention. Using an unprecedented and comprehensive collection of associated plant-pathogen samples, we investigated the degree of congruence between the genetic structures across Europe of two evolutionary and ecological model organisms, the anther-smut pathogen Microbotryum lychnidis-dioicae and its host plant Silene latifolia. We demonstrated a significant and particularly strong level of host-pathogen co-structure, with three main genetic clusters displaying highly similar spatial ranges in Western Europe, Eastern Europe and Italy, respectively. Correcting for the geographical component of genetic variation, significant correlations were still found between the genetic distances of anther-smut and host populations. Inoculation experiments suggested plant local adaptation, at the cluster level, for resistance to pathogens. These findings indicate that the pathogen remained isolated in the same fragmented southern refugia as its host plant during the last glaciation, and that little long-distance dispersal has occurred since the recolonization of Europe for either the plant or the pathogen, despite their known ability to travel across continents. This, together with the inoculation results, suggests that coevolutionary and competitive processes may be drivers of host-pathogen co-structure.
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Affiliation(s)
- Alice Feurtey
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France
| | - Pierre Gladieux
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France
- UMR BGPI, INRA, Montpellier, 34398, France
| | - Michael E Hood
- Department of Biology, Amherst College, Amherst, MA, 01002, USA
| | - Alodie Snirc
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France
| | - Amandine Cornille
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France
| | - Lisa Rosenthal
- Department of Biology, Amherst College, Amherst, MA, 01002, USA
| | - Tatiana Giraud
- Ecologie Systématique Evolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Orsay, 91400, France.
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Conservation genetics of the annual hemiparasitic plant Melampyrum sylvaticum (Orobanchaceae) in the UK and Scandinavia. CONSERV GENET 2016. [DOI: 10.1007/s10592-015-0803-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Swanson RJ, Hammond AT, Carlson AL, Gong H, Donovan TK. Pollen performance traits reveal prezygotic nonrandom mating and interference competition in Arabidopsis thaliana. AMERICAN JOURNAL OF BOTANY 2016; 103:498-513. [PMID: 26928008 DOI: 10.3732/ajb.1500172] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 10/01/2015] [Indexed: 06/05/2023]
Abstract
PREMISE The lack of ability to measure pollen performance traits in mixed pollinations has been a major hurdle in understanding the mechanisms of differential success of compatible pollen donors. In previous work, we demonstrated that nonrandom mating between two accessions of Arabidopsis thaliana, Columbia (Col) and Landsberg (Ler), is mediated by the male genotype. Despite these genetic insights, it was unclear at what stage of reproduction these genes were acting. Here, we used an experimental strategy that allowed us to differentiate different pollen populations in mixed pollinations to ask: (1) What pollen performance traits differed between Col and Ler accessions that direct nonrandom mating? (2) Is there evidence of interference competition? METHODS We used genetically marked pollen that can be visualized colorimetrically to quantify pollen performance of single populations of pollen in mixed pollinations. We used this and other assays to measure pollen viability, germination, tube growth, patterns of fertilization, and seed abortion. Finally, we assessed interference competition. RESULTS In mixed pollinations on Col pistils, Col pollen sired significantly more seeds than Ler pollen. Col pollen displayed higher pollen viability, faster and greater pollen germination, and faster pollen tube growth. We saw no evidence of nonrandom seed abortion. Finally, we found interference competition occurs in mixed pollinations. CONCLUSION The lack of differences in postzygotic processes coupled with direct observation of pollen performance traits indicates that nonrandom mating in Arabidopsis thaliana is prezygotic, due mostly to differential pollen germination and pollen tube growth rates. Finally, this study unambiguously demonstrates the existence of interference competition.
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Affiliation(s)
- Robert J Swanson
- Department of Biology, Valparaiso University, Valparaiso, Indiana 46383 USA
| | - Adam T Hammond
- Biophysical Sciences, The University of Chicago, Chicago, Illinois 60637 USA
| | - Ann L Carlson
- Department of Biology, Valparaiso University, Valparaiso, Indiana 46383 USA
| | - Hui Gong
- Department of Mathematics and Computer Science, Valparaiso University, Valparaiso, Indiana 46383 USA
| | - Thad K Donovan
- Smith Donovan Marketing & Communications, Chesterton, Indiana 46304 USA
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Pélabon C, Albertsen E, Falahati-Anbaran M, Wright J, Armbruster W. Does multiple paternity affect seed mass in angiosperms? An experimental test in Dalechampia scandens. J Evol Biol 2015; 28:1719-33. [DOI: 10.1111/jeb.12692] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 06/17/2015] [Accepted: 07/07/2015] [Indexed: 11/29/2022]
Affiliation(s)
- C. Pélabon
- Department of Biology; Centre for Biodiversity Dynamics; Norwegian University of Science and Technology; Trondheim Norway
| | - E. Albertsen
- Department of Biology; Centre for Biodiversity Dynamics; Norwegian University of Science and Technology; Trondheim Norway
| | - M. Falahati-Anbaran
- School of Biology and Center of Excellence in Phylogeny of Living Organisms; University of Tehran; Tehran Iran
- Department of Biology; Norwegian University of Science and Technology; Trondheim Norway
| | - J. Wright
- Department of Biology; Centre for Biodiversity Dynamics; Norwegian University of Science and Technology; Trondheim Norway
| | - W.S. Armbruster
- Department of Biology; Norwegian University of Science and Technology; Trondheim Norway
- School of Biological Sciences; King Henry Building; University of Portsmouth; Portsmouth UK
- Institute of Arctic Biology; University of Alaska; Fairbanks AK USA
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Broadhurst L. Pollen dispersal in fragmented populations of the dioecious wind-pollinated tree, Allocasuarina verticillata (drooping sheoak, drooping she-oak; Allocasuarinaceae). PLoS One 2015; 10:e0119498. [PMID: 25742183 PMCID: PMC4350918 DOI: 10.1371/journal.pone.0119498] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 01/21/2015] [Indexed: 11/28/2022] Open
Abstract
Vegetation clearing, land modification and agricultural intensification have impacted on many ecological communities around the world. Understanding how species respond to fragmentation and the scales over which functionality is retained, can be critical for managing biodiversity in agricultural landscapes. Allocasuarina verticillata (drooping sheoak, drooping she-oak) is a dioecious, wind-pollinated and -dispersed species with key conservation values across southeastern Australia. But vegetation clearing associated with agricultural expansion has reduced the abundance and spatial distribution of this species in many regions. Spatial genetic structure, relatedness among trees, pollen dispersal and mating patterns were examined in fragmented A. verticillata populations selected to represent the types of remnants that now characterise this species. Short scale spatial genetic structure (5-25 m) and relatedness among trees were observed in most populations. Unexpectedly, the two male trees closest to each female did not have a reproductive advantage accounting for only 4-15% of the seed produced in larger populations. Biparental inbreeding was also generally low (<4%) with limited evidence of seed crop domination by some male trees. More male trees contributed to seed crops in linear remnants (mean 17) compared to those from patch remnants (mean 11.3) which may reflect differences in pollen dispersal within the two remnant types. On average, pollen travels ~100 m irrespective of remnant type but was also detected to have dispersed as far as 1 km in open landscapes. Low biparental inbreeding, limited reproductive assurance for near-neighbour and probably related males and variability in the distances over which females sample pollen pools suggest that some mechanism to prevent matings between relatives exists in this species.
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Affiliation(s)
- Linda Broadhurst
- Centre for Australian National Biodiversity Research, National Research Collections, CSIRO, Canberra, Australia
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14
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Ala-Honkola O, Veltsos P, Anderson H, Ritchie MG. Copulation duration, but not paternity share, potentially mediates inbreeding avoidance in Drosophila montana. Behav Ecol Sociobiol 2014. [DOI: 10.1007/s00265-014-1807-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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15
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Losdat S, Chang SM, Reid JM. Inbreeding depression in male gametic performance. J Evol Biol 2014; 27:992-1011. [DOI: 10.1111/jeb.12403] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 04/01/2014] [Accepted: 04/02/2014] [Indexed: 12/23/2022]
Affiliation(s)
- S. Losdat
- Institute of Biological and Environmental Sciences; School of Biological Sciences; University of Aberdeen; Aberdeen UK
| | - S.-M. Chang
- Plant Biology Department; University of Georgia; Athens GA USA
| | - J. M. Reid
- Institute of Biological and Environmental Sciences; School of Biological Sciences; University of Aberdeen; Aberdeen UK
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16
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Carlson AL, Gong H, Toomajian C, Swanson RJ. Parental genetic distance and patterns in nonrandom mating and seed yield in predominately selfing Arabidopsis thaliana. PLANT REPRODUCTION 2013; 26:317-28. [PMID: 23843176 PMCID: PMC3825607 DOI: 10.1007/s00497-013-0228-5] [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: 05/16/2013] [Accepted: 07/03/2013] [Indexed: 05/09/2023]
Abstract
In this study, we ask two questions: (1) Is reproductive success independent of parental genetic distance in predominately selfing plants? (2) In the absence of early inbreeding depression, is there substantial maternal and/or paternal variation in reproductive success in natural populations? Seed yield in single pollinations and proportion of seeds sired in mixed pollinations were studied in genetically defined accessions of the predominately selfing plant Arabidopsis thaliana by conducting two diallel crosses. The first diallel was a standard, single pollination design that we used to examine variance in seed yield. The second diallel was a mixed pollination design that utilized a standard pollen competitor to examine variance in proportion of seeds sired. We found no correlation between reproductive success and parental genetic distance, and self-pollen does not systematically differ in reproductive success compared to outcross pollen, suggesting that Arabidopsis populations do not experience embryo lethality due to early-acting inbreeding or outbreeding depression. We used these data to partition the contributions to total phenotypic variation from six sources, including maternal contributions, paternal contributions and parental interactions. For seed yield in single pollinations, maternal effects accounted for the most significant source of variance (16.6 %). For proportion of seeds sired in mixed pollinations, the most significant source of variance was paternal effects (17.9 %). Thus, we show that population-level genetic similarities, including selfing, do not correlate with reproductive success, yet there is still significant paternal variance under competition. This suggests two things. First, since these differences are unlikely due to early-acting inbreeding depression or differential pollen viability, this implicates natural variation in pollen germination and tube growth dynamics. Second, this strongly supports a model of fixation of pollen performance genes in populations, offering a focus for future genetic studies in differential reproductive success.
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Affiliation(s)
- Ann L. Carlson
- Department of Biology, Valparaiso University, Valparaiso, IN 46383 USA
| | - Hui Gong
- Department of Mathematics and Computer Science, Valparaiso University, Valparaiso, IN 46383 USA
| | | | - Robert J. Swanson
- Department of Biology, Valparaiso University, Valparaiso, IN 46383 USA
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17
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Varga S, Vega-Frutis R, Kytöviita MM. Transgenerational effects of plant sex and arbuscular mycorrhizal symbiosis. THE NEW PHYTOLOGIST 2013; 199:812-821. [PMID: 23659431 DOI: 10.1111/nph.12305] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 04/02/2013] [Indexed: 06/02/2023]
Abstract
In gynodioecious plants, females are predicted to produce more and/or better offspring than hermaphrodites in order to be maintained in the same population. In the field, the roots of both sexes are usually colonized by arbuscular mycorrhizal (AM) fungi. Transgenerational effects of mycorrhizal symbiosis are largely unknown, although theoretically expected. We examined the maternal and paternal effects of AM fungal symbiosis and host sex on seed production and posterior seedling performance in Geranium sylvaticum, a gynodioecious plant. We hand-pollinated cloned females and hermaphrodites in symbiosis with AM fungi or in nonmycorrhizal conditions and measured seed number and mass, and seedling survival and growth in a glasshouse experiment. Females produced more seeds than hermaphrodites, but the seeds did not germinate, survive or grow better. Mycorrhizal plants were larger, but did not produce more seeds than nonmycorrhizal plants. Transgenerational parental effects of AM fungi were verified in seedling performance. This is the first study to show transgenerational mycorrhiza-mediated parental effects in a gynodioecious species. Mycorrhizal symbiosis affects plant fitness mainly through female functions with enduring effects on the next generation.
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Affiliation(s)
- Sandra Varga
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland.
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18
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Tuni C, Beveridge M, Simmons LW. Female crickets assess relatedness during mate guarding and bias storage of sperm towards unrelated males. J Evol Biol 2013; 26:1261-8. [PMID: 23745826 DOI: 10.1111/jeb.12118] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 01/06/2013] [Accepted: 01/07/2013] [Indexed: 11/30/2022]
Abstract
Recent evidence shows that females exert a post-copulatory fertilization bias in favour of unrelated males to avoid the genetic incompatibilities derived from inbreeding. One of the mechanisms suggested for fertilization biases in insects is female control over transport of sperm to the sperm-storage organs. We investigated post-copulatory inbreeding-avoidance mechanisms in females of the cricket Teleogryllus oceanicus. We assessed the relative contribution of related and unrelated males to the sperm stores of double-mated females. To demonstrate unequivocally that biased sperm storage results from female control rather than cryptic male choice, we manipulated the relatedness of mated males and of males performing post-copulatory mate guarding. Our results show that when guarded by a related male, females store less sperm from their actual mate, irrespective of the relatedness of the mating male. Our data support the notion that inhibition of sperm storage by female crickets can act as a form of cryptic female choice to avoid the severe negative effects of inbreeding.
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Affiliation(s)
- C Tuni
- Department of Bioscience, Aarhus University, Aarhus, Denmark
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19
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Jolivet C, Rogge M, Degen B. Molecular and quantitative signatures of biparental inbreeding depression in the self-incompatible tree species Prunus avium. Heredity (Edinb) 2012; 110:439-48. [PMID: 23211795 DOI: 10.1038/hdy.2012.103] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Genetic diversity strongly influences populations' adaptability to changing environments and therefore survival. Sustainable forest management practices have multiple roles including conservation of genetic resources and timber production. In this study, we aimed at better understanding the variation in genetic diversity among adult and offspring individuals, and the effects of mating system on offspring survival and growth in wild cherry, Prunus avium. We analysed adult trees and open pollinated seed-families from three stands in Germany at eight microsatellite loci and one incompatibility system locus and conducted paternity analyses. Seed viability testing and seed sowing in a nursery allowed further testing for the effects of pollen donor diversity and genetic similarity between mates on the offspring performance at the seed and seedling stages. Our results were contrasting across stands. Loss of genetic diversity from adult to seedling stages and positive effect of mate diversity on offspring performance occurred in one stand only, whereas biparental inbreeding depression and significant decrease in fixation index from adults to seedlings was detected in two stands. We discussed the effects of stand genetic diversity on the magnitude of biparental inbreeding depression at several life-stages and its consequences on the management of genetic resources in P. avium.
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Affiliation(s)
- C Jolivet
- Johann Heinrich von Thünen Institut vTI, Institute of Forest Genetics, D-22927 Grosshansdorf, Germany.
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20
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MAGALHAES ISABELS, GLEISER GABRIELA, LABOUCHE ANNEMARIE, BERNASCONI GIORGINA. Comparative population genetic structure in a plant-pollinator/seed predator system. Mol Ecol 2011; 20:4618-30. [DOI: 10.1111/j.1365-294x.2011.05296.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Affiliation(s)
- A F Agrawal
- Department of Ecology & Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2
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22
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Austerlitz F, Gleiser G, Teixeira S, Bernasconi G. The effects of inbreeding, genetic dissimilarity and phenotype on male reproductive success in a dioecious plant. Proc Biol Sci 2011; 279:91-100. [PMID: 21561968 DOI: 10.1098/rspb.2011.0652] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pollen fate can strongly affect the genetic structure of populations with restricted gene flow and significant inbreeding risk. We established an experimental population of inbred and outbred Silene latifolia plants to evaluate the effects of (i) inbreeding depression, (ii) phenotypic variation and (iii) relatedness between mates on male fitness under natural pollination. Paternity analysis revealed that outbred males sired significantly more offspring than inbred males. Independently of the effects of inbreeding, male fitness depended on several male traits, including a sexually dimorphic (flower number) and a gametophytic trait (in vitro pollen germination rate). In addition, full-sib matings were less frequent than randomly expected. Thus, inbreeding, phenotype and genetic dissimilarity simultaneously affect male fitness in this animal-pollinated plant. While inbreeding depression might threaten population persistence, the deficiency of effective matings between sibs and the higher fitness of outbred males will reduce its occurrence and counter genetic erosion.
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Affiliation(s)
- Frédéric Austerlitz
- Laboratoire Ecologie, Systématique et Evolution, UMR CNRS 8079, Université, Paris-Sud, 91405 Orsay Cedex, France
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23
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Ala-Honkola O, Manier MK, Lüpold S, Pitnick S. No evidence for postcopulatory inbreeding avoidance in Drosophila melanogaster. Evolution 2011; 65:2699-705. [PMID: 21884066 DOI: 10.1111/j.1558-5646.2011.01317.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Selection to avoid inbreeding is predicted to vary across species due to differences in population structure and reproductive biology. Over the past decade, there have been numerous investigations of postcopulatory inbreeding avoidance, a phenomenon that first requires discrimination of mate (or sperm) relatedness and then requires mechanisms of male ejaculate tailoring and/or cryptic female choice to avoid kin. The number of studies that have found a negative association between male-female genetic relatedness and competitive fertilization success is roughly equal to the number of studies that have not found such a relationship. In the former case, the underlying mechanisms are largely unknown. The present study was undertaken to verify and expand upon a previous report of postcopulatory inbreeding avoidance in D. melanogaster, as well as to resolve underlying mechanisms of inbreeding avoidance using transgenic flies that express a sperm head-specific fluorescent tag. However, siblings did not have a lower fertilization success as compared to unrelated males in either the first (P(1) ) or second (P(2) ) mate role in sperm competition with a standard unrelated competitor male in our study population of D. melanogaster. Analyses of mating latency, copulation duration, egg production rate, and remating interval further revealed no evidence for inbreeding avoidance.
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Affiliation(s)
- Outi Ala-Honkola
- Department of Biology, Syracuse University, Syracuse, New York 13244-1270, USA.
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24
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Wirth LR, Waser NM, Graf R, Gugerli F, Landergott U, Erhardt A, Linder HP, Holderegger R. Effects of floral neighborhood on seed set and degree of outbreeding in a high-alpine cushion plant. Oecologia 2011; 167:427-34. [PMID: 21484399 DOI: 10.1007/s00442-011-1985-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 03/22/2011] [Indexed: 11/30/2022]
Abstract
Plants flowering together may influence each other's pollination and fecundity over a range of physical distances. Their effects on one another can be competitive, neutral, or facilitative. We manipulated the floral neighborhood of the high-alpine cushion plant Eritrichium nanum in the Swiss Alps and measured the effects of co-flowering neighbors on both the number of seeds produced and the degree of inbreeding and outbreeding in the offspring, as deduced from nuclear microsatellite markers. Seed set of E. nanum did not vary significantly with the presence or absence of two Saxifraga species growing as near neighbors, but it was higher in E. nanum cushions growing at low conspecific density than in those growing at high density. In addition, floral neighborhood had no detectable effect on the degree of selfing of E. nanum, but seeds from cushions growing at low conspecific density were more highly outbred than seeds from cushions at high density. Thus, there was no evidence of either competition or facilitation between E. nanum and Saxifraga spp. as mediated by pollinators at the spatial scale of our experimental manipulation. In contrast, the greater fecundity of E. nanum cushions at low density was consistent with reduced intraspecific competition for pollinators and might also represent a beneficial effect of highly outbred seeds as brought about by more long-distance pollinator flights under low-density conditions.
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Affiliation(s)
- Lea R Wirth
- WSL Swiss Federal Research Institute, Birmensdorf, Switzerland
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25
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Griffiths ME, Tsvuura Z, Franklin DC, Lawes MJ. Pollination ecology of Isoglossa woodii, a long-lived, synchronously monocarpic herb from coastal forests in South Africa. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12:495-502. [PMID: 20522186 DOI: 10.1111/j.1438-8677.2009.00222.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Synchronous monocarpy in long-lived plants is often associated with pollination by wind, in part because infrequent mass flowering may satiate pollinators. Selfing in synchronous monocarps may provide reproductive assurance but conflict with the benefits of outcrossing, a key evolutionary driver of synchrony. We predicted that animal-pollinated species with synchronous flowering would have unspecialised flowers and attract abundant generalised pollinators, but predictions for selfing and outcrossing frequencies were not obvious. We examined the pollination biology of Isoglossa woodii (Acanthaceae), an insect-pollinated, monocarpic herb that flowers synchronously at 4-7-year intervals. The most frequent visitor to I. woodii flowers was the African honeybee, Apis mellifera adansonii. Hand-pollination failed to enhance seed production, indicating that the pollinators were not saturated. No seed was set in the absence of pollinators. Seed set was similar among selfed and outcrossed flowers, demonstrating a geitonogamous mixed-mating strategy with no direct evidence of preferential outcrossing. Flowers contained four ovules, but most fruits only developed one seed, raising the possibility that preferential outcrossing occurs by post-pollination processes. We argue that a number of the theoretical concerns about geitonogamous selfing as a form of reproductive assurance do not apply to a long-lived synchronous monocarp such as I. woodii.
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Affiliation(s)
- M E Griffiths
- Forest Biodiversity Research Unit, School of Biological and Conservation Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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26
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Hirao AS. Kinship between parents reduces offspring fitness in a natural population of Rhododendron brachycarpum. ANNALS OF BOTANY 2010; 105:637-46. [PMID: 20202970 PMCID: PMC2850802 DOI: 10.1093/aob/mcq018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 07/16/2009] [Accepted: 01/04/2010] [Indexed: 05/03/2023]
Abstract
BACKGROUND AND AIMS A reduction in offspring fitness resulting from mating between neighbours is interpreted as biparental inbreeding depression. However, little is known about the relationship between the parents' genetic relatedness and biparental inbreeding depression in their progeny in natural populations. This study assesses the effect of kinship between parents on the fitness of their progeny and the extent of spatial genetic structure in a natural population of Rhododendron brachycarpum. METHODS Kinship coefficients between 11,858 pairs of plants among a natural population of 154 R. brachycarpum plants were estimated a priori using six microsatellite markers. Plants were genotyped, and pairs were selected from among 60 plants to vary the kinship from full-sib to unrelated. After a hand-pollination experiment among the 60 plants, offspring fitness was measured at the stages of seed maturation (i.e. ripening) under natural conditions, and seed germination and seedling survival under greenhouse conditions. In addition, spatial autocorrelation was used to assess the population's genetic structure. KEY RESULTS Offspring fitness decreased significantly with increasing kinship between parents. However, the magnitude and timing of this effect differed among the life-cycle stages. Measures of inbreeding depression were 0.891 at seed maturation, 0.122 (but not significant) at seed germination and 0.506 at seedling survival. The local population spatial structure was significant, and the physical distance between parents mediated the level of inbreeding between them. CONCLUSIONS The level of inbreeding between individuals determines offspring fitness in R. brachycarpum, especially during seed maturation. Genetic relatedness between parents caused inbreeding depression in their progeny. Therefore, biparental inbreeding contributes little to reproduction and instead acts as a selection force that promotes outcrossing, as offspring of more distant (less related) parents survive better.
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Affiliation(s)
- Akira S Hirao
- Institute of Mountain Science, Shinshu University, Matsumoto 390-8621, Japan.
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27
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Labouche AM, Bernasconi G. Male moths provide pollination benefits in theSilene latifolia-Hadena bicrurisnursery pollination system. Funct Ecol 2009. [DOI: 10.1111/j.1365-2435.2009.01658.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Burkhardt A, Internicola A, Bernasconi G. Effects of pollination timing on seed paternity and seed mass in Silene latifolia (Caryophyllaceae). ANNALS OF BOTANY 2009; 104:767-73. [PMID: 19567418 PMCID: PMC2729624 DOI: 10.1093/aob/mcp154] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Competition among genetically different pollen donors within one recipient flower may play an important role in plant populations, increasing offspring genetic diversity and vigour. However, under field conditions stochastic pollen arrival times may result in disproportionate fertilization success of the first-arriving pollen, even to the detriment of the recipient plant's and offspring fitness. It is therefore critical to evaluate the relative importance of arrival times of pollen from different donors in determining siring success. METHODS Hand pollinations and genetic markers were used to investigate experimentally the effect of pollination timing on seed paternity, seed mass and stigmatic wilting in the the dioecious plant Silene latifolia. In this species, high prevalence of multiply-sired fruits in natural populations suggests that competition among different donors may often take place (at fertilization or during seed development); however, the role of variation due to pollen arrival times is not known. KEY RESULTS First-arriving pollen sired significantly more seeds than later-arriving pollen. This advantage was expressed already before the first pollen tubes could reach the ovary. Simultaneously with pollen tube growth, the stigmatic papillae wilted visibly. Individual seeds were heavier in fruits where one donor sired most seeds than in fruits where both donors had more even paternity shares. CONCLUSIONS In field populations of S. latifolia, fruits are often multiply-sired. Because later-arriving pollen had decreased chances of fertilizing the ovules, this implies that open-pollinated flowers often benefit from pollen carry-over or pollinator visits within short time intervals, which may contribute to increase offspring genetic diversity and fitness.
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RAHMÉ J, WIDMER A, KARRENBERG S. Pollen competition as an asymmetric reproductive barrier between two closely relatedSilenespecies. J Evol Biol 2009; 22:1937-43. [DOI: 10.1111/j.1420-9101.2009.01803.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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30
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Szövényi P, Ricca M, Shaw AJ. Multiple paternity and sporophytic inbreeding depression in a dioicous moss species. Heredity (Edinb) 2009; 103:394-403. [PMID: 19623211 DOI: 10.1038/hdy.2009.82] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Multiple paternity (polyandry) frequently occurs in flowering plants and animals and is assumed to have an important function in the evolution of reproductive traits. Polyandry in bryophytes may occur among multiple sporophytes of a female gametophyte; however, its occurrence and extent is unknown. In this study we investigate the occurrence and extent of multiple paternity, spatial genetic structure, and sporophytic inbreeding depression in natural populations of a dioicous bryophyte species, Sphagnum lescurii, using microsatellite markers. Multiple paternity is prevalent among sporophytes of a female gametophyte and male genotypes exhibit significant skew in paternity. Despite significant spatial genetic structure in the population, suggesting frequent inbreeding, the number of inbred and outbred sporophytes was balanced, resulting in an average fixation coefficient and population level selfing rate of zero. In line with the prediction of sporophytic inbreeding depression sporophyte size was significantly correlated with the level of heterozygosity. Furthermore, female gametophytes preferentially supported sporophytes with higher heterozygosity. These results indicate that polyandry provides the opportunity for postfertilization selection in bryophytes having short fertilization distances and spatially structured populations facilitating inbreeding. Preferential maternal support of the more heterozygous sporophytes suggests active inbreeding avoidance that may have significant implications for mating system evolution in bryophytes.
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Affiliation(s)
- P Szövényi
- Department of Biology, Duke University, 139 Biological Sciences Bldg., Box 90338, Durham, NC 27708, USA.
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