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Jiao F, Wang X, Zhang A. Asymmetrical disassortative pollination mediated by long-/short-tongued pollinators in a distylous Limonium myrianthum (Plumbaginaceae) with a short corolla tubular small flower. Ecol Evol 2024; 14:e11284. [PMID: 38651164 PMCID: PMC11033550 DOI: 10.1002/ece3.11284] [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: 11/28/2023] [Revised: 03/20/2024] [Accepted: 04/03/2024] [Indexed: 04/25/2024] Open
Abstract
In heterostylous plants, short-tongued pollinators are often ineffective/inefficient owing to the limitations imposed by a long corolla tube. However, it is unclear how disassortative pollen transfer is achieved in small flowers. We investigated the pollination pattern and floral morph variation by analyzing heterostylous syndrome, pollinator groups, and pollen deposition after a single visitation in two Limonium myrianthum populations with short-corolla-tubular small flowers. The predominant pollinators in the Hutubi population were pollen-seeking short-tongued syrphids, which can only transfer pollen between high-level sexual organs. In the Xishan population, nectar-seeking short-tongued insects were efficient pollinators with symmetrical disassortative pollen transfer between high- and low-level sexual organs, whereas long-tongued pollinators had a low efficiency between high-level sexual organs due to the low contact probability with the stigma of long-styled flowers (L-morph), which no longer offered the same advantage observed in tubular flowers. Asymmetrical disassortative pollination may cause the female fitness of short-styled (S-morph) individuals in the Hutubi and L-morph individuals in the Xishan population to suffer greater selection pressure and exhibit a higher degree of floral morph variation. Limonium myrianthum exhibits an unusual pollination pattern in which the small flowers with short corolla tubes make it possible for short-tongued insects to become effective pollinators. However, factors such as the position of stigma-anther within the flower, pollinator species and their preference further caused asymmetrical disassortative pollen transfer. Therefore, more factors should be considered when evaluating the effectiveness of short- and long-tongued insects in pollination service.
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Affiliation(s)
- Fangfang Jiao
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, School of Life Science and TechnologyXinjiang UniversityUrumqiChina
| | - Xiaowei Wang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, School of Life Science and TechnologyXinjiang UniversityUrumqiChina
| | - Aiqin Zhang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, School of Life Science and TechnologyXinjiang UniversityUrumqiChina
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Ren D, Jiao F, Zhang A, Zhao J, Zhang J. Floral morph variation mediated by clonal growth and pollinator functional groups of Limonium otolepis in a heterostylous fragmented population. AOB PLANTS 2024; 16:plae020. [PMID: 38660050 PMCID: PMC11041057 DOI: 10.1093/aobpla/plae020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 03/26/2024] [Indexed: 04/26/2024]
Abstract
Abstract. Heterostyly, a genetic style polymorphism, is linked to symmetric pollen transfer, vital for its maintenance. Clonal growth typically impacts sexual reproduction by influencing pollen transfer. However, the floral morph variation remains poorly understood under the combined effects of pollinators and clonal growth in heterostyly characterized by negative frequency-dependent selection and disassortative mating. We estimated morph ratios, ramets per genet and heterostylous syndrome and quantified legitimate pollen transfer via clonal growth, pollinators and reciprocal herkogamy between floral morphs in Limonium otolepis, a fragmented population composed of five subpopulations in the desert environment of northwestern China, with small flower and large floral morph variation. All subpopulations but one exhibited pollen-stigma morphology dimorphism. The compatibility between mating types with different pollen-stigma morphologies remained consistent regardless of reciprocal herkogamy. Biased ratios and ramets per genet of the two mating types with distinct pollen-stigma morphologies caused asymmetric pollen flow and varying fruit sets in all subpopulations. Short-tongued insects were the primary pollinators due to small flower sizes. However, pollen-feeding Syrphidae sp. triggered asymmetry in pollen flow between high and low sex organs, with short-styled morphs having lower stigma pollen depositions and greater variation. Clonal growth amplified this variation by reducing intermorph pollen transfer. All in all, pollinators and clonal growth jointly drive floral morph variation. H-morphs with the same stigma-anther position and self-incompatibility, which mitigate the disadvantages of sunken low sex organs with differing from the classical homostyly, might arise from long- and short-styled morphs through a 'relaxed selection'. This study is the first to uncover the occurrence of the H-morph and its associated influencing factors in a distylous plant featuring clonal growth, small flowers and a fragmented population.
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Affiliation(s)
- Dengfu Ren
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, School of Life Science and Technology, Xinjiang University, Urumqi 830017, P.R China
| | - Fangfang Jiao
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, School of Life Science and Technology, Xinjiang University, Urumqi 830017, P.R China
| | - Aiqin Zhang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, School of Life Science and Technology, Xinjiang University, Urumqi 830017, P.R China
| | - Jing Zhao
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, School of Life Science and Technology, Xinjiang University, Urumqi 830017, P.R China
| | - Jing Zhang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, School of Life Science and Technology, Xinjiang University, Urumqi 830017, P.R China
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Płażek A, Kopeć P, Dziurka M, Słomka A. The yield of common buckwheat (Fagopyrum esculentum Moench) depends on the genotype but not on the Pin-to-Thrum ratio. Sci Rep 2023; 13:16022. [PMID: 37749231 PMCID: PMC10519966 DOI: 10.1038/s41598-023-43059-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 09/19/2023] [Indexed: 09/27/2023] Open
Abstract
Common buckwheat has a complicated flowering biology. It is characterized by a strong self-incompatibility resulting from heterostyly, i.e. the occurrence of two types of flowers: Pin and Thrum, differing in the length of pistils and stamens. Fertilization occurs only as a result of cross-pollination between these morphs. Suspicions exist that the disturbed ratio between plants producing Pin and Thrum flowers (with the latter type generating more seeds) causes low seed yield. The aim of the study was to analyze: (1) the ratio between plants with Pin and Thrum morphs, (2) flower and seed production, as well as abortion of flowers, (3) the composition of nectar collected at an early flowering stage and during full flowering. The study was performed under semi-controlled and field conditions on six Polish accessions. The results indicated that under semi-controlled conditions the Pin-to-Thrum ratio was indeed disproportionate; such a phenomenon is called anisoplethy. In the field, however, the Pin-to-Thrum ratio was well-balanced (isoplethy). The plants with both morphs aborted a similar percentage of flowers and produced a comparable number of empty seeds. The number of flowers, their abortion, and ripe seed production were independent of flower type, however, they were genotypically controlled. A strong correlation between the number of flowers produced by a plant, flower abortion and the number of empty seeds was found. The percentage of aborted flowers correlated positively with the weight of ripe seeds. Nectar composition was similar for all buckwheat genotypes, but we found some differences in the amount of individual sugars depending on the blooming stage. In the majority of accessions, the nectar produced at the early blooming stage was characterized by a greater mass and volume, and contained more individual sugars than at the full-flowering stage.
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Affiliation(s)
- Agnieszka Płażek
- Department of Breeding, Physiology of Plants and Seed Science, Faculty of Agriculture and Economics, University of Agriculture of Krakow, Podłużna 3, 30-239, Kraków, Poland.
| | - Przemysław Kopeć
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Michał Dziurka
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Aneta Słomka
- Department of Plant Cytology and Embryology, Institute of Botany, Faculty of Biology, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Kraków, Poland.
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Mora‐Carrera E, Stubbs RL, Keller B, Léveillé‐Bourret É, de Vos JM, Szövényi P, Conti E. Different molecular changes underlie the same phenotypic transition: Origins and consequences of independent shifts to homostyly within species. Mol Ecol 2023; 32:61-78. [PMID: 34761469 PMCID: PMC10078681 DOI: 10.1111/mec.16270] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 12/29/2022]
Abstract
The repeated transition from outcrossing to selfing is a key topic in evolutionary biology. However, the molecular basis of such shifts has been rarely examined due to lack of knowledge of the genes controlling these transitions. A classic example of mating system transition is the repeated shift from heterostyly to homostyly. Occurring in 28 angiosperm families, heterostyly is characterized by the reciprocal position of male and female sexual organs in two (or three) distinct, usually self-incompatible floral morphs. Conversely, homostyly is characterized by a single, self-compatible floral morph with reduced separation of male and female organs, facilitating selfing. Here, we investigate the origins of homostyly in Primula vulgaris and its microevolutionary consequences by integrating surveys of the frequency of homostyles in natural populations, DNA sequence analyses of the gene controlling the position of female sexual organs (CYPᵀ), and microsatellite genotyping of both progeny arrays and natural populations characterized by varying frequencies of homostyles. As expected, we found that homostyles displace short-styled individuals, but long-style morphs are maintained at low frequencies within populations. We also demonstrated that homostyles repeatedly evolved from short-styled individuals in association with different types of loss-of-function mutations in CYPᵀ. Additionally, homostyly triggers a shift to selfing, promoting increased inbreeding within and genetic differentiation among populations. Our results elucidate the causes and consequences of repeated transitions to homostyly within species, and the putative mechanisms precluding its fixation in P. vulgaris. This study represents a benchmark for future analyses of losses of heterostyly in other angiosperms.
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Affiliation(s)
- Emiliano Mora‐Carrera
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZurichSwitzerland
| | - Rebecca L. Stubbs
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZurichSwitzerland
| | - Barbara Keller
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZurichSwitzerland
| | - Étienne Léveillé‐Bourret
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZurichSwitzerland
- Département de Sciences BiologiquesInstitut de Recherche en Biologie VégétaleUniversité de MontréalMontréalQuébecCanada
| | - Jurriaan M. de Vos
- Department of Environmental Sciences – BotanyUniversity of BaselBaselSwitzerland
| | - Peter Szövényi
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZurichSwitzerland
| | - Elena Conti
- Department of Systematic and Evolutionary BotanyUniversity of ZurichZurichSwitzerland
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Losch F, Liedtke S, Vautz W, Weigend M. Evaluation of floral volatile patterns in the genus Narcissus using gas chromatography-coupled ion mobility spectrometry. APPLICATIONS IN PLANT SCIENCES 2023; 11:e11506. [PMID: 36818782 PMCID: PMC9934524 DOI: 10.1002/aps3.11506] [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: 06/08/2022] [Revised: 10/19/2022] [Accepted: 10/20/2022] [Indexed: 06/18/2023]
Abstract
PREMISE Daffodils (Narcissus, Amaryllidaceae) are iconic ornamentals with a complex floral biology and many fragrant species; however, little is known about floral plant volatile organic compounds (pVOCs) across the genus and additional sampling is desirable. The present study investigates whether the floral scent of 20 species of Narcissus can be characterized using gas chromatography-coupled ion mobility spectrometry (GC-IMS), with the aim of building a comparative pVOC data set for ecological and evolutionary studies. METHODS We used a commercial GC-IMS equipped with an integrated in-line enrichment system for a fast, sensitive, and automated pVOC analysis. This facilitates qualitative and (semi)-quantitative measurements without sample preparation. RESULTS The GC-IMS provided detailed data on floral pVOCs in Narcissus with very short sampling times and without floral enclosure. A wide range of compounds was recorded and partially identified. The retrieved pVOC patterns showed a good agreement with published data, and five "chemotypes" were characterized as characteristic combinations of floral volatiles. DISCUSSION The GC-IMS setup can be applied to rapidly generate large amounts of pVOC data with high sensitivity and selectivity. The preliminary data on Narcissus obtained here indicate both considerable pVOC variability and a good correspondence of the pVOC patterns with infrageneric classification, supporting the hypothesis that floral scent could represent a considerable phylogenetic signal.
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Affiliation(s)
- Florian Losch
- Nees‐Institut für Biodiversität der Pflanzen, Mathematisch‐Naturwissenschaftliche FakultätRheinische Friedrich‐Wilhelmsuniversität Bonn53115BonnGermany
| | - Sascha Liedtke
- ION‐GAS GmbHKonrad‐Adenauer‐Allee 1144263DortmundGermany
| | - Wolfgang Vautz
- ION‐GAS GmbHKonrad‐Adenauer‐Allee 1144263DortmundGermany
- Leibniz‐Institut für Analytische Wissenschaften – ISAS – e.V.Bunsen‐Kirchhoff‐Straße 1144139DortmundGermany
| | - Maximilian Weigend
- Nees‐Institut für Biodiversität der Pflanzen, Mathematisch‐Naturwissenschaftliche FakultätRheinische Friedrich‐Wilhelmsuniversität Bonn53115BonnGermany
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Simón‐Porcar VI, Muñoz‐Pajares AJ, de Castro A, Arroyo J. Direct evidence supporting Darwin's hypothesis of cross-pollination promoted by sex organ reciprocity. THE NEW PHYTOLOGIST 2022; 235:2099-2110. [PMID: 35596603 PMCID: PMC9546006 DOI: 10.1111/nph.18266] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/09/2022] [Indexed: 05/28/2023]
Abstract
The floral phenotype plays a main role in the attraction and fit of pollinators. Both perianth traits and the positioning of sex organs can be subjected to natural selection and determine nonrandom mating patterns in populations. In stylar-polymorphic species, the Darwinian hypothesis predicts increased mating success between individuals with sex organs at equivalent heights (i.e. with higher reciprocity). We used paternity analyses in experimental populations of a stylar-dimorphic species. By comparing the observed mating patterns with those expected under random mating, we tested the effects of sex organ reciprocity and perianth traits on mating success. We also analysed phenotypic selection on perianth traits through female and male functions. The (dis)similarity of parental perianth traits had no direct effects on the mating patterns. Sex organ reciprocity had a positive effect on mating success. Narrow floral tubes increased this effect in upper sex organs. Perianth traits showed little signs of phenotypic selection. Female and absolute fitness measures resulted in different patterns of phenotypic selection. We provide precise empirical evidence of the Darwinian hypothesis about the functioning of stylar polymorphisms, demonstrating that mating patterns are determined by sex organ reciprocity and only those perianth traits which are critical to pollinator fit.
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Affiliation(s)
| | - A. Jesús Muñoz‐Pajares
- Department of GeneticsUniversity of GranadaE‐18071GranadaSpain
- Research Centre in Biodiversity and Genetic Resources (CIBIO)Campus Agrário de Vairão4485‐661VairãoPortugal
| | - Alejandra de Castro
- Department of Plant Biology and EcologyUniversity of SevilleE‐41080SevilleSpain
| | - Juan Arroyo
- Department of Plant Biology and EcologyUniversity of SevilleE‐41080SevilleSpain
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Ganguly S, Barua D. Inter-morph pollen flow and reproductive success in a self-compatible species with stigma-height dimorphism: the influence of herkogamy and reciprocity. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:939-946. [PMID: 34396659 DOI: 10.1111/plb.13308] [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: 04/06/2021] [Accepted: 06/07/2021] [Indexed: 06/13/2023]
Abstract
Inter-morph pollen transfer and its dependence on herkogamy and reciprocity are not completely understood in species with stigma-height dimorphism. We asked whether total stigmatic pollen loads, inter-morph fraction of pollen load and reproductive success differed between morphs in Jasminum malabaricum, a species exhibiting stigma-height dimorphism. We tested whether higher herkogamy and reciprocity resulted in higher inter-morph pollen deposition and reproductive success. We quantified individual-level estimates of herkogamy, reciprocity, total stigmatic pollen load, inter-morph stigmatic pollen fraction and fruit set for both morphs in naturally occurring populations of J. malabaricum. Total pollen load was higher in the long-styled morph, inter-morph pollen fraction was higher in the short-styled morph, but fruit set did not differ between morphs. Higher herkogamy resulted in a higher inter-morph fraction of pollen load and fruit set in the long-styled morph of one population. In the other population, only reciprocity was found to be related to inter-morph pollen deposition. This study is the first to quantify and report natural inter-morph stigmatic pollen load in a species with stigma-height dimorphism. Morph-specific differences in pollen load were similar to patterns commonly observed in heterostylous species. The results highlight the importance of both herkogamy and reciprocity in facilitating inter-morph pollen transfer. Population-specific patterns indicate that local environmental factors determine the relative functional importance of herkogamy and reciprocity.
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Affiliation(s)
- S Ganguly
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - D Barua
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
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Ganguly S, Barua D. High herkogamy but low reciprocity characterizes isoplethic populations of Jasminum malabaricum, a species with stigma-height dimorphism. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:899-909. [PMID: 32352185 DOI: 10.1111/plb.13127] [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: 11/29/2019] [Accepted: 04/21/2020] [Indexed: 06/11/2023]
Abstract
Studies of floral polymorphisms have focused on heterostyly, while stigma-height dimorphism has received considerably less attention. Few studies have examined the reproductive biology of species with stigma-height dimorphism to understand how factors influencing mate availability and pollen transfer are related to morph ratios in populations. Floral morphological traits, especially herkogamy and reciprocity, pollinator visitation, breeding system and spatiotemporal mate availability, are known to affect inter-morph pollination and morph ratios in species with stigma-height dimorphism. In this study, we investigated the presence of stigma-height dimorphism and estimated morph ratios in four naturally occurring populations of Jasminum malabaricum. We quantified morph- and population-specific differences in the abovementioned factors in these populations to understand the observed morph ratios. The positions of anthers and stigmas were characteristic of stigma-height dimorphism, the first report of this polymorphism in the genus. All study populations were isoplethic, implying equal fitness of both morphs. Herkogamy was higher in the short-styled morph, while reciprocity was higher between the long-styled stigma and short-styled anthers. Long- and short-tongued pollinators were common floral visitors, and we observed no differences between morphs in spatiotemporal mate availability or pollinator visitation. Neither morph exhibited self- or heteromorphic incompatibility. The short-styled stigma had lower reciprocity but likely receives sufficient inter-morph pollen from long-tongued pollinators, and also by avoiding self-pollination due to higher herkogamy. These results highlight the importance of sufficient effective pollinators and floral morphological features, particularly herkogamy, in maintaining isoplethy in species with stigma-height dimorphism.
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Affiliation(s)
- S Ganguly
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - D Barua
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
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Matias R, Pérez-Barrales R, Consolaro H. Patterns of variation in distylous traits and reproductive consequences in Erythroxylum species and populations. AMERICAN JOURNAL OF BOTANY 2020; 107:910-922. [PMID: 32462680 DOI: 10.1002/ajb2.1478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 03/16/2020] [Indexed: 06/11/2023]
Abstract
PREMISE Distylous species possess two floral morphs with reciprocal positioning of stigmas and anthers that is hypothesized to promote disassortative pollination. Theoretical models predict equal morph frequencies, but many populations depart from the expected 1:1 ratio, a pattern that often correlates with asymmetric mating between morphs and/or presence of a weak incompatibility system. Variation in reciprocity can also affect the likelihood of disassortative pollination and, hence, reproductive fitness. METHODS We described variation in incompatibility systems and morph ratio in four Erythroxylum species to test if greater deviations from 1:1 ratios occur in populations of self-compatible species. Using adaptive inaccuracy, we described upper and lower organ reciprocity in species and populations and assessed the relationship of reciprocity to population means and coefficients of variation for fruit set to test if reciprocity could predict female reproductive success. RESULTS Morphs occurred in 1:1 ratios in most populations of three Erythroxylum species with distylous self-incompatibility. In self-compatible E. campestre populations showed an excess of the long-styled morph, the short-styled morph, or were monomorphic for the short-styled morph. We detected deviations from reciprocity, with total inaccuracy ranging between 9.39% and 42.94%, and inaccuracy values were lowest in low organs. Across populations, we found a positive relationship between inaccuracy and the coefficient of variation of fruit set. CONCLUSIONS Erythroxylum species showed variation in the distylous syndrome, with changes in the incompatibility system that corresponded with deviations from 1:1 morph ratio, and variation in reciprocity that correlated with variation in female reproductive fitness.
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Affiliation(s)
- Raphael Matias
- Graduate Program in Botany, University of Brasília, Brasília, Distrito Federal, Brazil
- Academic Areas Department, Federal Institute of Goiás, Águas Lindas, Goiás, Brazil
| | | | - Hélder Consolaro
- Biotechnology Institute, Federal University of Catalão, Catalão, Goiás, Brazil
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Lázaro A, Seguí J, Santamaría L. Continuous variation in herkogamy enhances the reproductive response of Lonicera implexa to spatial variation in pollinator assemblages. AOB PLANTS 2020; 12:plz078. [PMID: 31976054 PMCID: PMC6969618 DOI: 10.1093/aobpla/plz078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 12/03/2019] [Indexed: 05/14/2023]
Abstract
Herkogamy, the spatial separation of sex organs in hermaphroditic plants, has been proposed as a mechanism to reduce self-pollination and the associated processes of inbreeding and gamete wastage. Longitudinal herkogamy is the most frequent type, with two subtypes: approach herkogamy (anthers below the stigma), which is associated with diverse pollinator arrays, and reverse herkogamy (anthers above the stigma), associated with specialized, long-tongued pollinators. By using a herkogamy index that varied continuously from negative (reverse herkogamy) to positive (approach herkogamy) values, we studied the effect of continuous variation in herkogamy on pollinator attraction, selfing capability and plant fitness across three populations of Lonicera implexa differing in the relative abundance of long-tongued vs. short-tongued pollinators. Reverse herkogamy was significantly more frequent in the population where long-tongued pollinators were dominant than in the other two populations. Agreeing with this, the main floral visitors of L. implexa individuals with small and large herkogamy index were, respectively, long-tongued and short-tongued pollinators. Spontaneous selfing was low and increased with increasing herkogamy index (i.e. with approach herkogamy), although most of it occurred when there was close distance between anthers and stigma. Fruit production was unrelated to the herkogamy index in the population with long-tongued pollinators, but it increased with approach herkogamy (higher herkogamy index) in the other two populations. In contrast, seeds of individuals with reverse herkogamy (smaller herkogamy indices) germinated better. In this species, continuous variation in herkogamy might function as a reproductive strategy, as different morphotypes might be favoured by different pollinator assemblages.
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Affiliation(s)
- Amparo Lázaro
- Global Change Research Group, Mediterranean Institute for Advanced Studies (IMEDEA; UIB-CSIC), Esporles, Balearic Islands, Spain
| | - Jaume Seguí
- Global Change Research Group, Mediterranean Institute for Advanced Studies (IMEDEA; UIB-CSIC), Esporles, Balearic Islands, Spain
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Barranco D, Arroyo J, Santos-Gally R. Avoiding sexual interference: herkogamy and dichogamy in style dimorphic flowers of Narcissus broussonetii (Amaryllidaceae). AOB PLANTS 2019; 11:plz038. [PMID: 31528325 PMCID: PMC6735907 DOI: 10.1093/aobpla/plz038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Spatial (herkogamy) or temporal (dichogamy) separation of sex organs are mechanisms considered to restrict self-pollination and promote outcrossing. Additionally, avoidance of self-interference is proposed to be the driving force for the evolution of these mechanisms, particularly in self-incompatible species. However, species with anthers and stigmas at different levels may increase the rate of imprecise pollen transfer, resulting in pollen discounting. Non-reciprocal stylar dimorphism has been considered a transitional, unstable stage towards the evolution of reciprocal style dimorphism (distyly), to simultaneously avoid interference and lack of precision. In this study we investigate the spatial and temporal separation of sex organs in a population of the style dimorphic and self-incompatible Narcissus broussonetii and their consequences in the reciprocity between the sex organs of morphs and their fecundity. First, we evaluated the relative growth of sex organs after anthesis. Then, we studied the stigma receptivity along the flower lifespan including its effect on seed production in both morphs. Finally, given the weak reciprocity between the sex organs of morphs of this species, we estimated population genetic diversity parameters in Long- and Short-styled plants to explore differences between them as a result of rates of inbreeding due to different mating strategies. We observed that Long-styled plants and Short-styled plants present different strategies to avoid sexual interference and both of them had negative consequences in the reciprocity between the sex organs of morphs. Long-styled plants exhibited a delay in stigma receptivity and a higher growth rate of the style after anthesis, while Short-styled plants presented higher herkogamy and no delay in stigma receptivity. These findings suggest that the avoidance of self-interference, in stylar dimorphic Narcissus species, seems to be more critical than improving of reciprocity between the sex organs of morphs. This might explain why reciprocal herkogamy (distyly) is rare in the genus.
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Affiliation(s)
- Daniel Barranco
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, apartado, Sevilla, Spain
| | - Juan Arroyo
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, apartado, Sevilla, Spain
| | - Rocío Santos-Gally
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, apartado, Sevilla, Spain
- CONACyT-Instituto de Ecología, A.P. 70-275, Ciudad Universitaria, Universidad Nacional Autónoma de México, Ciudad de México, México
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Arima K, Kyogoku D, Nakahama N, Suetsugu K, Ohtani M, Ishii C, Terauchi H, Terauchi Y, Isagi Y. Mating pattern of a distylous primrose in a natural population: unilateral outcrossing and asymmetric selfing between sexual morphs. Evol Ecol 2018. [DOI: 10.1007/s10682-018-9965-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Pérez-Barrales R, Abarca CA, Santos-Gally R, Schiestl FP, Arroyo J. The function of the floral corona in the pollination of a Mediterranean style dimorphic daffodil. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20 Suppl 1:118-127. [PMID: 29105981 DOI: 10.1111/plb.12657] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
Narcissus papyraceus is a style dimorphic species with two floral forms, with anthers at similar height and stigmas above (long-styled L) and below (short-styled S) the anther level. The species is self-incompatible, but intra- and inter-morph compatible. Populations are either dimorphic (including both morphs) in the region of the Strait of Gibraltar, or L-monomorphic (with only L plants) in the inland of the Iberian Peninsula. This variation correlates with the most common floral visitors, being primarily long-tongued and short-tongued pollinators, respectively, a rare condition in Mediterranean plants. The maintenance of S-flowers relies on long-tongued insects, as only those deliver pollen to short-styled stigmas. Narcissus flowers present a long and narrow tube, at the bottom of which nectar accumulates, and a floral corona, which has been proposed as an important trait for the attraction of pollinators. Here we tested the importance of the corona on pollination of L and S flowers. We described UV reflectance patterns of the corona and tepals, and characterised VOCs in intact flowers and flowers with trimmed coronas. We also conducted a field experiment in the dimorphic and monomorphic region to estimate the importance of corona removal on seed production in stands with solitary plants and in groups to control for compatible pollen limitation. Reflectance was higher in the tepals than the corona, although both traits presented a reflectance peak around 450 nm wavelength. L- and S-flowers produced similar volatiles, regardless of the manipulation of the corona. Across dimorphic and monomorphic regions, S-flowers with the corona removed suffered a reduction in seed production of ca. 50%, while seed production remained similar in L flowers both with the corona intact and removed. Plants in solitary stands suffered a strong reduction in seed production, which was more pronounced in the monomorphic region. Our results suggest that the corona in Narcissus is more important for the pollination of S-flowers, which generally have lower seed production compared to L-flowers. Taken together, these results suggest that the floral corona indirectly plays an important role for maintenance of the polymorphism.
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Affiliation(s)
- R Pérez-Barrales
- School of Biological Sciences, University of Portsmouth, Portsmouth, UK
| | - C A Abarca
- Unidad Lerma Departamento de Ecología Evolutiva, Departamento de Ciencias Ambientales, Universidad Autónoma Metropolitana, Mexico City, México
| | - R Santos-Gally
- CONACYT-Departamento de Ecología Evolutiva, Instituto de Ecología, UNAM, Mexico City, México
| | - F P Schiestl
- Institute of Systematic Botany, University of Zurich, Zurich, Switzerland
| | - J Arroyo
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
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Kameyama Y, Watanabe M, Kurosawa H, Nishimori T, Matsue D, Takyu M. Seasonal changes in pollen limitation and femaleness along the snowmelt gradient in a distylous alpine herb, Primula modesta. Ecol Evol 2015; 5:5352-5363. [PMID: 30151137 PMCID: PMC6102533 DOI: 10.1002/ece3.1803] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/14/2015] [Accepted: 10/03/2015] [Indexed: 11/16/2022] Open
Abstract
Flowering phenology of alpine plants is strongly determined by the timing of snowmelt, and the conditions of pollination of widely distributed plants vary greatly during their flowering season. We examined the reproductive success of the distylous alpine herb, Primula modesta, along the snowmelt gradient under natural conditions, and compared it with the result of artificial pollination experiments. In addition, the compositions and visit frequencies of pollinators to the flower of P. modesta were examined during the flowering period. The pin and thrum plants of P. modesta growing at the same site have an equal ability to produce seeds if a sufficient amount of legitimate pollen grains are deposited on the stigma surface. However, under natural conditions, their seed‐set success was often (even if not always) restricted by pollen limitation, and the functional gender of the pin and thrum plants biased to the female and male, respectively, associated with their growing sites. These variations were not ascribed to resource limitation nor biased morph ratio but to the seasonal changes in pollination situations, a replacement of pollinator types from long‐ to short‐tongued pollinators resulted in unidirectional pollen transfer from long stamens (thrum plants) to long styles (pin plants). The functional gender specialization may enhance the evolution of dioecy from heterostyly, but the severe pollen limitation may cause the breakdown of heterostyly into homostyly. To consider the evolutionary pathway of heterostylous plants, an accumulation of the empirical data is required demonstrating how phenological synchrony between plants and pollinators is decided and to what degree this relationship is stable over years, along with estimates of selection and gene flow in individual plants.
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Affiliation(s)
- Yoshiaki Kameyama
- Faculty of Regional Environment Science Tokyo University of Agriculture Tokyo 156-8502 Japan
| | - Manami Watanabe
- Faculty of Regional Environment Science Tokyo University of Agriculture Tokyo 156-8502 Japan.,Present address: OTA Floriculture Auction Co., Ltd. Tokyo 143-0001 Japan
| | - Hideki Kurosawa
- Faculty of Regional Environment Science Tokyo University of Agriculture Tokyo 156-8502 Japan.,Present address: Tamamura-machi Sawa-gun Gunma 370-1105 Japan
| | - Takuya Nishimori
- Faculty of Regional Environment Science Tokyo University of Agriculture Tokyo 156-8502 Japan.,Present address: OTA Floriculture Auction Co., Ltd. Tokyo 143-0001 Japan
| | - Daisuke Matsue
- Faculty of Regional Environment Science Tokyo University of Agriculture Tokyo 156-8502 Japan.,Present address: Hakone Botanical Garden of Wetlands Kanagawa 205-0631 Japan
| | - Masaaki Takyu
- Faculty of Regional Environment Science Tokyo University of Agriculture Tokyo 156-8502 Japan
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15
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Simón-Porcar VI, Meagher TR, Arroyo J. Disassortative mating prevails in style-dimorphicNarcissus papyraceusdespite low reciprocity and compatibility of morphs. Evolution 2015. [DOI: 10.1111/evo.12731] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Thomas R. Meagher
- School of Biology; University of St. Andrews; St. Andrews United Kingdom
| | - Juan Arroyo
- Departamento de Biología Vegetal y Ecología; Universidad de Sevilla; Sevilla Spain
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16
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Simón-Porcar VI, Picó FX, Arroyo J. Range-wide population genetics and variation in morph ratio in style-dimorphic Narcissus papyraceus. AMERICAN JOURNAL OF BOTANY 2015; 102:449-456. [PMID: 25784478 DOI: 10.3732/ajb.1400209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
UNLABELLED • PREMISE OF THE STUDY Theoretical models state that natural selection and mating patterns account for floral morph ratio in style-polymorphic plants. However, the demographic history of populations can also influence variation in morph ratios. If so, we hypothesize an association between the morph ratios and the genetic structure across populations.• METHODS We used nuclear microsatellites to assess genetic variation and structure in populations of Narcissus papyraceus, a style-dimorphic plant whose floral morph ratios (L-morph to S-morph) gradually vary throughout its distribution range in the southwestern Mediterranean Basin. We implemented analyses to relate the genetic features of populations with their morph ratios.• KEY RESULTS We found greater frequencies of the S-morph in central populations and declining frequencies toward the periphery. This geographic pattern was not associated with the genetic structure of populations. Instead, we found two distinct genetic groups, mainly separated by the Strait of Gibraltar, with a mixture of morph ratios within each one. Overall, there was a weak genetic structure. Genetic diversity was greater in central and southern dimorphic populations than in northern L-monomorphic populations.• CONCLUSIONS Altogether, our results do not support the hypothesis that the demographic history of populations can account for the observed geographical pattern of morph ratios in N. papyraceus. We suggest that adaptive processes shown in previous studies in the species are the main determinant of the existing variation in the morph composition of populations.
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Affiliation(s)
- Violeta I Simón-Porcar
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Apartado 1095 41080 Sevilla, Spain Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - F Xavier Picó
- Departamento de Ecología Integrativa, Estación Biológica de Doñana (EBD), Consejo Superior de Investigaciones Científicas (CSIC) 41092 Sevilla, Spain
| | - Juan Arroyo
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Apartado 1095 41080 Sevilla, Spain
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17
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Zhu XF, Jiang XF, Li L, Zhang ZQ, Li QJ. Asymmetrical disassortative pollination in a distylous primrose: the complementary roles of bumblebee nectar robbers and syrphid flies. Sci Rep 2015; 5:7721. [PMID: 25579323 PMCID: PMC4289899 DOI: 10.1038/srep07721] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 12/08/2014] [Indexed: 11/17/2022] Open
Abstract
Heterostyly is a floral polymorphism characterized by reciprocal herkogamy maintained through high levels of mating between morphs, serviced by appropriate pollinators. We studied how differential efficiency and abundance of distinct pollinators affect plant female reproduction in self- and intra-morph incompatible distylous Primula secundiflora. Bumblebees and syrphid flies were found to be the most abundant floral visitors. Bumblebees frequently exhibited nectar-robbing behavior. Because the robbing holes were always situated between the high- and low-level organs on both morphs, nectar-robbing bumblebees only pollinated S-styled flowers. L-styled flowers set four times as many seeds as did S-styled flowers after being visited by pollen-collecting syrphid flies. The natural female fecundity and the magnitude of pollen limitation varied between the morphs within populations because of the mosaic distribution of nectar-robbing bumblebees and syrphid flies. L-styled flowers and S-styled flowers set the same number of seeds after supplemental hand pollination, indicating equivalent female reproductive potential. We suggest that bumblebee nectar robbers and syrphid flies play an important role in sustaining the floral dimorphism of heterostyly in P. secundiflora because of their complementary roles in the pollination system.
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Affiliation(s)
- Xing-Fu Zhu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, China
- University of Chinese Academy of Sciences, 10049, China
| | - Xian-Feng Jiang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, China
- University of Chinese Academy of Sciences, 10049, China
| | - Li Li
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, China
- University of Chinese Academy of Sciences, 10049, China
| | - Zhi-Qiang Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650204, China
| | - Qing-Jun Li
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, China
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Valiente‐Banuet A, Aizen MA, Alcántara JM, Arroyo J, Cocucci A, Galetti M, García MB, García D, Gómez JM, Jordano P, Medel R, Navarro L, Obeso JR, Oviedo R, Ramírez N, Rey PJ, Traveset A, Verdú M, Zamora R. Beyond species loss: the extinction of ecological interactions in a changing world. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12356] [Citation(s) in RCA: 483] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Alfonso Valiente‐Banuet
- Departamento de Ecología de la Biodiversidad Instituto de Ecología Universidad Nacional Autónoma de México Ap. Postal 70‐275 México 04510 DF México
| | - Marcelo A. Aizen
- Laboratorio Ecotono‐CRUB Universidad Nacional del Comahue and INIBIOMA 8400 San Carlos de Bariloche Río NegroArgentina
| | - Julio M. Alcántara
- Departamento de Biología Animal, Biología Vegetal y Ecología Universidad de Jaén E‐23071 Jaén Spain
| | - Juan Arroyo
- Departamento de Biología Vegetal y Ecología Universidad de Sevilla Apdo. 1095 E‐41080 Sevilla Spain
| | - Andrea Cocucci
- Laboratorio de Biología Floral Instituto Multidisciplinario de Biología Vegetal (IMBIV)CONICET‐Universidad Nacional de Córdoba Casilla de Correo 495 5000 Córdoba Argentina
| | - Mauro Galetti
- Departamento de Ecologia Universidade Estadual Paulista (UNESP) 13506‐900 Rio Claro Sao Paulo Brazil
| | - María B. García
- Instituto Pirenaico de Ecología CSIC Apdo. 13034 E‐50080 Zaragoza Spain
| | - Daniel García
- Departamento de Biología de Organismos y Sistemas Universidad de Oviedo Unidad Mixta de Investigación en Biodiversidad (UMIB CSIC‐UO‐PA) E‐33071 Oviedo Spain
| | - José M. Gómez
- Departamento de Ecología Funcional y Evolutiva Estación Experimental de Zonas Aridas (EEZA‐CSIC) Ctra Sacramento s/n La Cañada de San Urbano E‐04120 Almería Spain
- Departamento de Ecología Facultad de Ciencias Universidad de Granada E‐18071 Granada Spain
| | - Pedro Jordano
- Integrative Ecology Group Estación Biológica de Doñana (EBD‐CSIC) Avda. Americo Vespucio s/n Isla de La Cartuja E‐41092 Sevilla Spain
| | - Rodrigo Medel
- Departamento de Ciencias Ecológicas Facultad de Ciencias Universidad de Chile Casilla 653 Santiago Chile
| | - Luis Navarro
- Department of Plant Biology and Soil Sciences Faculty of Biology University of Vigo As Lagoas‐Marcosende E‐36200 Vigo Spain
| | - José R. Obeso
- Departamento de Biología de Organismos y Sistemas Universidad de Oviedo Unidad Mixta de Investigación en Biodiversidad (UMIB CSIC‐UO‐PA) E‐33071 Oviedo Spain
| | - Ramona Oviedo
- Instituto de Ecología y Sistemática de La Habana Carretera Varona 11835 e/ Oriente y Lindero La Habana 19 Cp 11900 Calabazar Boyeros Cuba
| | - Nelson Ramírez
- Facultad de Ciencias Instituto de Biología Experimental Universidad Central de Venezuela Aptdo. 48312 Caracas 1041A Venezuela
| | - Pedro J. Rey
- Departamento de Biología Animal, Biología Vegetal y Ecología Universidad de Jaén E‐23071 Jaén Spain
| | - Anna Traveset
- Terrestrial Ecology Group Laboratorio Internacional de Cambio Global (LINC‐Global) Institut Mediterrani d'Estudis Avançats (CSIC‐UIB) C/Miquel Marqués 21 E‐07190 Esporles Mallorca Balearic Islands Spain
| | - Miguel Verdú
- Centro de Investigaciones sobre Desertificación (CIDE CSIC‐UV‐GV) Apartado Oficial E‐46113 Moncada Valencia Spain
| | - Regino Zamora
- Departamento de Ecología Facultad de Ciencias Universidad de Granada E‐18071 Granada Spain
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19
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Haller BC, de Vos JM, Keller B, Hendry AP, Conti E. A tale of two morphs: modeling pollen transfer, magic traits, and reproductive isolation in parapatry. PLoS One 2014; 9:e106512. [PMID: 25211280 PMCID: PMC4161326 DOI: 10.1371/journal.pone.0106512] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/14/2014] [Indexed: 12/25/2022] Open
Abstract
The evolution of the flower is commonly thought to have spurred angiosperm diversification. Similarly, particular floral traits might have promoted diversification within specific angiosperm clades. We hypothesize that traits promoting the precise positional transfer of pollen between flowers might promote diversification. In particular, precise pollen transfer might produce partial reproductive isolation that facilitates adaptive divergence between parapatric populations differing in their reproductive-organ positions. We investigate this hypothesis with an individual-based model of pollen transfer dynamics associated with heterostyly, a floral syndrome that depends on precise pollen transfer. Our model shows that precise pollen transfer can cause sexual selection leading to divergence in reproductive-organ positions between populations served by different pollinators, pleiotropically causing an increase in reproductive isolation through a "magic trait" mechanism. Furthermore, this increased reproductive isolation facilitates adaptive divergence between the populations in an unlinked, ecologically selected trait. In a different pollination scenario, however, precise pollen transfer causes a decrease in adaptive divergence by promoting asymmetric gene flow. Our results highlight the idea that magic traits are not "magic" in isolation; in particular, the effect size of magic traits in speciation depends on the external environment, and also on other traits that modify the strength of the magic trait's influence on non-random mating. Overall, we show that the evolutionary consequences of pollen transfer dynamics can depend strongly on the available pollinator fauna and on the morphological fit between flowers and pollinators. Furthermore, our results illustrate the potential importance of even weak reproductive isolating barriers in facilitating adaptive divergence.
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Affiliation(s)
- Benjamin C. Haller
- Redpath Museum and Deptartment of Biology, McGill University, Montréal, Québec, Canada
- * E-mail:
| | - Jurriaan M. de Vos
- Deptartment of Ecology and Evol. Biol., Brown University, Providence, Rhode Island, United States of America
- Institute of Systematic Botany, University of Zürich, Zürich, Switzerland
| | - Barbara Keller
- Institute of Systematic Botany, University of Zürich, Zürich, Switzerland
| | - Andrew P. Hendry
- Redpath Museum and Deptartment of Biology, McGill University, Montréal, Québec, Canada
| | - Elena Conti
- Institute of Systematic Botany, University of Zürich, Zürich, Switzerland
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Pérez-Barrales R, Simón-Porcar VI, Santos-Gally R, Arroyo J. Phenotypic integration in style dimorphic daffodils (Narcissus, Amaryllidaceae) with different pollinators. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130258. [PMID: 25002703 PMCID: PMC4084543 DOI: 10.1098/rstb.2013.0258] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Different pollinators can exert different selective pressures on floral traits, depending on how they fit with flowers, which should be reflected in the patterns of variation and covariation of traits. Surprisingly, empirical evidence in support of this view is scarce. Here, we have studied whether the variation observed in floral phenotypic integration and covariation of traits in Narcissus species is associated with different groups of pollinators. Phenotypic integration was studied in two style dimorphic species, both with dimorphic populations mostly visited by long-tongued pollinators (close fit with flowers), and monomorphic populations visited by short-tongued insects (loose fit). For N. papyraceus, the patterns of variation and correlation among traits involved in different functions (attraction and fit with pollinators, transfer of pollen) were compared within and between population types. The genetic diversity of populations was also studied to control for possible effects on phenotypic variation. In both species, populations with long-tongued pollinators displayed greater phenotypic integration than those with short-tongued pollinators. Also, the correlations among traits involved in the same function were stronger than across functions. Furthermore, traits involved in the transfer of pollen were consistently more correlated and less variable than traits involved in the attraction of insects, and these differences were larger in dimorphic than monomorphic populations. In addition, population genetic parameters did not correlate with phenotypic integration or variation. Altogether, our results support current views of the role of pollinators in the evolution of floral integration.
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Affiliation(s)
- Rocío Pérez-Barrales
- School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK Departmento de Biología Vegetal y Ecología, University of Seville, Seville 41080, Spain
| | | | - Rocío Santos-Gally
- Departmento de Biología Vegetal y Ecología, University of Seville, Seville 41080, Spain
| | - Juan Arroyo
- Departmento de Biología Vegetal y Ecología, University of Seville, Seville 41080, Spain
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Santos-Gally R, Gonzalez-Voyer A, Arroyo J. DECONSTRUCTING HETEROSTYLY: THE EVOLUTIONARY ROLE OF INCOMPATIBILITY SYSTEM, POLLINATORS, AND FLORAL ARCHITECTURE. Evolution 2013; 67:2072-82. [DOI: 10.1111/evo.12087] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 01/25/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Rocío Santos-Gally
- Departamento de Biología Vegetal y Ecología; Universidad de Sevilla; Apartado 1095 41080 Sevilla Spain
| | - Alejandro Gonzalez-Voyer
- Department of Integrative Ecology; Estación Biológica de Doñana (EBD-CSIC); Av Américo Vespucio SN; 41092 Sevilla Spain
| | - Juan Arroyo
- Departamento de Biología Vegetal y Ecología; Universidad de Sevilla; Apartado 1095 41080 Sevilla Spain
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Santos-Gally R, Pérez-Barrales R, Simón VI, Arroyo J. The role of short-tongued insects in floral variation across the range of a style-dimorphic plant. ANNALS OF BOTANY 2013; 111:317-28. [PMID: 23223205 PMCID: PMC3555527 DOI: 10.1093/aob/mcs261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 11/07/2012] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS Heterostyly and related style polymorphisms are suitable model systems to evaluate the importance of functional pollinators in the maintenance of population variability. In Narcissus papyraceus different functional pollinators, incompatibility system and flower morphology have been proposed to influence the maintenance of polymorphism through their effect on disassortative mating. Here a test is done to find out if the visitation rate of long- versus short-tongued pollinators correlates with the morph ratio and if the latter is related to other flower traits of the species across its main geographic range. METHODS Floral traits from 34 populations in the south-west of the Iberian Peninsula and in north-west Africa were measured, perianth variation was described and a comparison was made of allometric relationships between sex organs and floral tube. Correlations between pollinator guilds, stigma-anther separation of reciprocal morphs (our proxy for disassortative mating) and morph-ratio variation were analysed. Finally, the incompatibility system of the species in the northern and southern borders of its distribution are described. KEY RESULTS Flowers from southern populations were significantly larger than flowers from centre and northern populations. The abundance of short-styled plants decreased gradually with increasing distance from the core region (the Strait of Gibraltar), with these disappearing only in the northern range. Although there was a significant difference in stigma-anther separation among populations, morph ratio was not associated with reciprocity or floral tube length. Long-style morph frequency increased with short-tongued pollinator visitation rate. Populations from both edges of the distribution range were self-incompatible and within- and between-morph compatible. CONCLUSIONS The style morph ratio changed gradually, whereas perianth trait variation showed abrupt changes with two morphotypes across the range. The positive relationship between the visitation rate of short-tongued pollinators and the decrease of the short-style morph supports our initial hypothesis. The results highlight the importance of different pollinators in determining the presence of style polymorphism.
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Affiliation(s)
- Rocío Santos-Gally
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain.
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23
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Keller B, de Vos JM, Conti E. Decrease of sexual organ reciprocity between heterostylous primrose species, with possible functional and evolutionary implications. ANNALS OF BOTANY 2012; 110:1233-44. [PMID: 23002269 PMCID: PMC3478057 DOI: 10.1093/aob/mcs199] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 07/26/2012] [Indexed: 05/11/2023]
Abstract
BACKGROUND AND AIMS Heterostyly is a floral polymorphism that has fascinated evolutionary biologists since Darwin's seminal studies on primroses. The main morphological characteristic of heterostyly is the reciprocal placement of anthers and stigmas in two distinct (distyly) floral morphs. Variation in the degree of intermorph sexual reciprocity is relatively common and known to affect patterns of pollen transfer within species. However, the partitioning of sexual organ reciprocity within and between closely related species remains unknown. This study aimed at testing whether intermorph sexual reciprocity differs within vs. between primrose species that hybridize in nature and whether the positions of sexual organs are correlated with other floral traits. METHODS Six floral traits were measured in both floral morphs of 15 allopatric populations of Primula elatior, P. veris and P. vulgaris, and anther-stigma reciprocity was estimated within and between species. A combination of univariate and multivariate approaches was used to test whether positions of reproductive organs were less reciprocal between than within species, to assess correlations between sexual organ positions and other corolla traits, and to quantify differences between morphs and species. KEY RESULTS The three species were morphologically well differentiated in most floral traits, except that P. veris and P. vulgaris did not differ significantly in sexual organ positions. Overall, lower interspecific than intraspecific sexual organ reciprocity was detected. This decrease was marked between P. elatior and P. vulgaris, intermediate and variable between P. elatior and P. veris, but negligible between P. veris and P. vulgaris. CONCLUSIONS Differences in anther and stigma heights between the analysed primrose species were of the same magnitude or larger than intraspecific differences that altered pollen flow within other heterostylous systems. Therefore, it is possible to suggest that considerable reductions of sexual organ reciprocity between species may lower interspecific pollen flow, with potential effects on reproductive isolation.
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Affiliation(s)
- Barbara Keller
- Institute of Systematic Botany, University of Zurich, 8008 Zurich, Switzerland
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Sletvold N, Trunschke J, Wimmergren C, Ågren J. Separating selection by diurnal and nocturnal pollinators on floral display and spur length inGymnadenia conopsea. Ecology 2012; 93:1880-91. [DOI: 10.1890/11-2044.1] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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25
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Zhou W, Barrett SCH, Wang H, Li DZ. Loss of floral polymorphism in heterostylous Luculia pinceana (Rubiaceae): a molecular phylogeographic perspective. Mol Ecol 2012; 21:4631-45. [PMID: 22970974 DOI: 10.1111/j.1365-294x.2012.05707.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Both deterministic and stochastic forces determine the representation and frequency of floral morphs in heterostylous plant populations. Phylogeographic analysis of molecular variation can provide information on the role of historical factors, including founder events, in affecting population morph structure. Here, we investigate geographical patterns of floral morph variation in a distylous shrub Luculia pinceana (Rubiaceae) by examining the relations between floral polymorphism and molecular (cpDNA and microsatellite) variation in 25 populations sampled throughout the distribution of the species in southwest China and adjacent countries. In 19 of the 25 populations, the frequency of floral morphs was not significantly different from the expected 1:1 ratio. The remaining populations were either L-morph biased (2) or monomorphic (4) for this form and were morphologically differentiated from the remaining populations in several floral traits, that is, corolla tube length, sex organ position and stigma-anther separation. Phylogeographic analysis supports the hypothesis that L. pinceana was initially split into west-central and eastern lineages in the Early Pleistocene (~1.982 Mya). A centrally located lineage composed of morph-biased and monomorphic populations appears to have been subsequently derived from the west-central lineage, perhaps by a founder event after the last glacial maximum. Hypotheses to explain why these populations have not returned to equilibrium morph frequencies are considered.
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Affiliation(s)
- Wei Zhou
- Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
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BAENA-DíAZ F, FORNONI J, SOSENSKI P, MOLINA-FREANER FE, WELLER SG, PÉREZ-ISHIWARA R, DOMÍNGUEZ CA. Changes in reciprocal herkogamy during the tristyly-distyly transition in Oxalis alpina increase efficiency in pollen transfer. J Evol Biol 2012; 25:574-83. [DOI: 10.1111/j.1420-9101.2012.02455.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hermann K, Kuhlemeier C. The genetic architecture of natural variation in flower morphology. CURRENT OPINION IN PLANT BIOLOGY 2011; 14:60-65. [PMID: 20934369 DOI: 10.1016/j.pbi.2010.09.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 09/11/2010] [Indexed: 05/30/2023]
Abstract
A pollination syndrome is defined as a suite of floral traits that are associated with the attraction of a specific group of animals as pollinators. Traits such as flower morphology, color, scent, and rewards contribute to the plant's reproductive success by attracting pollinators. Here we focus on the genetics of natural variation in flower morphology and how the adaptation between plants and their cognate pollinator class contributes to plant's reproductive success. We review recent work on the genetic basis of interspecific differences in reproductive organ morphology and discuss possible genetic mechanisms for coordinated changes in complex syndromes.
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Affiliation(s)
- Katrin Hermann
- Institute of Plant Sciences, University of Berne, Altenbergrain 21, CH-3013 Berne, Switzerland
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