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Simón-Porcar V, Escudero M, Santos-Gally R, Sauquet H, Schönenberger J, Johnson SD, Arroyo J. Convergent evolutionary patterns of heterostyly across angiosperms support the pollination-precision hypothesis. Nat Commun 2024; 15:1237. [PMID: 38336937 PMCID: PMC10858259 DOI: 10.1038/s41467-024-45118-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 01/12/2024] [Indexed: 02/12/2024] Open
Abstract
Since the insights by Charles Darwin, heterostyly, a floral polymorphism with morphs bearing stigmas and anthers at reciprocal heights, has become a model system for the study of natural selection. Based on his archetypal heterostylous flower, including regular symmetry, few stamens and a tube, Darwin hypothesised that heterostyly evolved to promote outcrossing through efficient pollen transfer between morphs involving different areas of a pollinator's body, thus proposing his seminal pollination-precision hypothesis. Here we update the number of heterostylous and other style-length polymorphic taxa to 247 genera belonging to 34 families, notably expanding known cases by 20%. Using phylogenetic and comparative analyses across the angiosperms, we show numerous independent origins of style-length polymorphism associated with actinomorphic, tubular flowers with a low number of sex organs, stamens fused to the corolla, and pollination by long-tongued insects. These associations provide support for the Darwinian pollination-precision hypothesis as a basis for convergent evolution of heterostyly across angiosperms.
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Affiliation(s)
- Violeta Simón-Porcar
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, E-41080, Sevilla, Spain.
- School of Life Sciences, University of KwaZulu-Natal, P Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa.
| | - Marcial Escudero
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, E-41080, Sevilla, Spain
| | | | - Hervé Sauquet
- National Herbarium of New South Wales, Royal Botanic Gardens and Domain Trust, Sydney, NSW, Australia
| | - Jürg Schönenberger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030, Vienna, Austria
| | - Steven D Johnson
- School of Life Sciences, University of KwaZulu-Natal, P Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa
| | - Juan Arroyo
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, E-41080, Sevilla, Spain.
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Zhang L, Li P, Zhang X, Li J. Two floral forms in the same species-distyly. PLANTA 2023; 258:72. [PMID: 37656285 DOI: 10.1007/s00425-023-04229-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 08/23/2023] [Indexed: 09/02/2023]
Abstract
MAIN CONCLUSION This paper reviews the progress of research on the morphology, physiology and molecular biology of distyly in plants. It will help to elucidate the mysteries of distyly in plants. Distyly is a unique representative type of heterostyly in plants, primarily characterized by the presence of long style and short style within the flowers of the same species. This interesting trait has always fascinated researchers. With the rapid development of molecular biology, the molecular mechanism for the production of dimorphic styles in plants is also gaining ground. Researchers have been studying plant dimorphic styles from various perspectives. The researchers are gradually unravelling the mechanisms by which plants produce distyly traits. This paper reviews advances in the study of plant dimorphic style characteristics, mainly in terms of the morphology, physiology and molecular biology of plants with dimorphic styles. The aim is to provide a theoretical basis for the study of the mechanism of distyly formation in plants.
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Affiliation(s)
- Lu Zhang
- College of Landscape and Tourism, Hebei Agricultural University, No. 289 Lingyusi Street, P. O. Box 28, Baoding, 071000, Hebei, China
| | - Ping Li
- College of Landscape and Tourism, Hebei Agricultural University, No. 289 Lingyusi Street, P. O. Box 28, Baoding, 071000, Hebei, China.
| | - Xiaoman Zhang
- College of Landscape and Tourism, Hebei Agricultural University, No. 289 Lingyusi Street, P. O. Box 28, Baoding, 071000, Hebei, China.
| | - Jinfeng Li
- College of Landscape and Tourism, Hebei Agricultural University, No. 289 Lingyusi Street, P. O. Box 28, Baoding, 071000, Hebei, China
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Wang Y, Lan Y, Ye H, Feng X, Qie Q, Liu L, Chai M. Reproductive Biology and Breeding Systems of Two Opisthopappus Endemic and Endangered Species on the Taihang Mountains. PLANTS (BASEL, SWITZERLAND) 2023; 12:1954. [PMID: 37653873 PMCID: PMC10222883 DOI: 10.3390/plants12101954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/24/2023] [Accepted: 04/29/2023] [Indexed: 09/02/2023]
Abstract
Opisthopappus is a perennial, endemic herb of the Taihang Mountains in China. Two species of this genus (O. longilobus and O. taihangensis) are important wild genetic resources for Asteraceae; however, their reproductive biology has been lacking until now. This study is the first detailed report on the reproductive biology and breeding systems of two Opisthopappus species. Through field observations, the floral syndromes of O. longilobus and O. taihangensis were found to possess a similar pattern, although O. taihangensis has a relatively larger capitulum, more ray ligules, and disc florets. The flowers of both O. longilobus and O. taihangensis are protandrous, a character that can prevent autogamy at the single-flower level, and insects are required for pollination. Further, brightly ligules, brightly bisexual florets, unique fragrance, and amount of nectar suggest that these species propagate via an entomophilous pollination system. Hymenopteran and Diptera species were observed as the effective pollinators for these two species. The outcrossing index, pollen/ovule ratio and the results of hand pollination indicated that these Opisthopappus species might have a mixed mating system that combines cross-fertilization and partial self-fertilization for O. longilobus and O. taihangensis, outcrossing predominated in the breeding system, while self-pollination played an important role in seed production when insect pollination was unavailable, particularly in a harsh environment, such as the Taihang Mountains cliffs. Meanwhile, O. taihangensis might better adapt to severe surroundings with relatively complex floral syndromes, specifically through the attraction of visiting insects and a high seed set rate. The above results not only provide reference information toward a better understanding of the survival strategies of O. longilobus and O. taihangensis in the Taihang Mountains but also lay a solid foundation for further exploring the molecular mechanisms that underly their adaptation under cliff environments.
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Affiliation(s)
- Yiling Wang
- School of Life Sciences, Shanxi Normal University, Taiyuan 030031, China; (Y.L.); (X.F.); (Q.Q.); (L.L.)
| | - Yafei Lan
- School of Life Sciences, Shanxi Normal University, Taiyuan 030031, China; (Y.L.); (X.F.); (Q.Q.); (L.L.)
| | - Hang Ye
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China;
| | - Xiaolong Feng
- School of Life Sciences, Shanxi Normal University, Taiyuan 030031, China; (Y.L.); (X.F.); (Q.Q.); (L.L.)
| | - Qiyang Qie
- School of Life Sciences, Shanxi Normal University, Taiyuan 030031, China; (Y.L.); (X.F.); (Q.Q.); (L.L.)
| | - Li Liu
- School of Life Sciences, Shanxi Normal University, Taiyuan 030031, China; (Y.L.); (X.F.); (Q.Q.); (L.L.)
| | - Min Chai
- School of Life Sciences, Shanxi Normal University, Taiyuan 030031, China; (Y.L.); (X.F.); (Q.Q.); (L.L.)
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Martín-Hernanz S, Albaladejo RG, Lavergne S, Rubio E, Marín-Rodulfo M, Arroyo J, Aparicio A. Strong conservatism of floral morphology during the rapid diversification of the genus Helianthemum. AMERICAN JOURNAL OF BOTANY 2023; 110:e16155. [PMID: 36912727 DOI: 10.1002/ajb2.16155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 05/16/2023]
Abstract
PREMISE Divergence of floral morphology and breeding systems are often expected to be linked to angiosperm diversification and environmental niche divergence. However, available evidence for such relationships is not generalizable due to different taxonomic, geographical and time scales. The Palearctic genus Helianthemum shows the highest diversity of the family Cistaceae in terms of breeding systems, floral traits, and environmental conditions as a result of three recent evolutionary radiations since the Late Miocene. Here, we investigated the tempo and mode of evolution of floral morphology in the genus and its link with species diversification and environmental niche divergence. METHODS We quantified 18 floral traits from 83 taxa and applied phylogenetic comparative methods using a robust phylogenetic framework based on genotyping-by-sequencing data. RESULTS We found three different floral morphologies, putatively related to three different breeding systems: type I, characterized by small flowers without herkogamy and low pollen to ovule ratio; type II, represented by large flowers with approach herkogamy and intermediate pollen to ovule ratio; and type III, featured by small flowers with reverse herkogamy and the highest pollen to ovule ratio. Each morphology has been highly conserved across each radiation and has evolved independently of species diversification and ecological niche divergence. CONCLUSIONS The combined results of trait, niche, and species diversification ultimately recovered a pattern of potentially non-adaptive radiations in Helianthemum and highlight the idea that evolutionary radiations can be decoupled from floral morphology evolution even in lineages that diversified in heterogeneous environments as the Mediterranean Basin.
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Affiliation(s)
- Sara Martín-Hernanz
- Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
- Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3DS, UK
| | - Rafael G Albaladejo
- Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - Sébastien Lavergne
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, Laboratoire d'Ecologie Alpine (LECA), FR-38000, Grenoble, France
| | - Encarnación Rubio
- Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - Macarena Marín-Rodulfo
- Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
- Departamento de Botánica, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Juan Arroyo
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Abelardo Aparicio
- Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
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Diverse mating consequences of the evolutionary breakdown of the sexual polymorphism heterostyly. Proc Natl Acad Sci U S A 2023; 120:e2214492120. [PMID: 36595698 PMCID: PMC9926269 DOI: 10.1073/pnas.2214492120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Reproductive systems of flowering plants are evolutionarily fluid, with mating patterns changing in response to shifts in abiotic conditions, pollination systems, and population characteristics. Changes in mating should be particularly evident in species with sexual polymorphisms that become ecologically destabilized, promoting transitions to alternative reproductive systems. Here, we decompose female mating portfolios (incidence of selfing, outcross mate number, and intermorph mating) in eight populations of Primula oreodoxa, a self-compatible insect-pollinated herb. This species is ancestrally distylous, with populations subdivided into two floral morphs that usually mate with each other (disassortative mating). Stages in the breakdown of polymorphism also occur, including "mixed" populations of distylous and homostylous (self-pollinating) morphs and purely homostylous populations. Population morph ratios vary with elevation in association with differences in pollinator availability, providing an unusual opportunity to investigate changes in mating patterns accompanying transitions in reproductive systems. Unexpectedly, individuals mostly outcrossed randomly, with substantial disassortative mating in at most two distylous populations. As predicted, mixed populations had higher selfing rates than distylous populations, within mixed populations, homostyles selfed almost twice as much as the distylous morphs, and homostylous populations exhibited the highest selfing rates. Populations with homostyles outcrossed with fewer mates and mate number varied negatively with population selfing rates. These differences indicate maintenance of distyly at low elevation, transition to monomorphic selfing at high elevation, and uncertain, possibly variable fates at intermediate elevation. By quantifying the earliest changes in mating that initiate reproductive transitions, our study highlights the key role of mating in promoting evolutionary divergence.
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