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Delbón NE, Aliscioni NL, Lorenzati M, García S, Singer RB, Gurvich DE. Looking for non-hermaphrodite cacti: multidisciplinary studies in Gymnocalycium bruchii endemic to central Argentina. PLANT REPRODUCTION 2024; 37:201-214. [PMID: 36941510 DOI: 10.1007/s00497-023-00461-y] [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: 11/02/2022] [Accepted: 03/07/2023] [Indexed: 05/25/2023]
Abstract
KEY MESSAGE Through a multidisciplinary study we found that Gymnocalycium bruchii, an endemic cactus from central Argentina, acts as a dioecious species, which is the first record in this genus. Cactaceae species are typically hermaphroditic; however, about 2% have other different reproductive systems. These non-hermaphroditic species may develop sexual dimorphism in flowers or other reproductive, vegetative or ecological traits, besides a specific breeding system and floral ontogeny. Therefore, multidisciplinary research is necessary to fully understand reproduction in those species. For this purpose, we studied Gymnocalicium bruchii, a globose cactus endemic to central Argentina that is presumably dioecious or gynodioecious. We made observations in two natural and two cultivated populations. We made morphological observations of plants and flowers, and performed quantitative analyses to determine the sex ratio, size of plants and flowers, flower production, fruiting, among other variables. We performed hand-pollination, self-fertilization and free-pollination tests to determine the breeding system. Finally, we studied the anatomy and ontogeny of the reproductive organs using permanent histological slides of flower morphs at different stages. Our results confirm that Gymnocalicium bruchii is a dioecious species. Female flowers have atrophied anthers and a functional gynoecium that produces fruits and seeds. Male flowers are bigger and have a functional androecium but a sterile gynoecium. In the cultivated population, the sex ratio was 1/1, whereas the number of male individuals was higher in both natural populations. Pollination tests corroborated dioecy. Ontogenetic studies revealed that in female flowers the anthers collapse before microspore maturation, while in male flowers the gynoecium shows normal development of the ovary, style, stigma, and ovules; however, the latter are never fertilized.
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Affiliation(s)
- Natalia E Delbón
- Facultad de Ciencias Exactas, Físicas y Naturales, Instituto Multidisciplinario de Biología Vegetal (UNC-CONICET), Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, CC495, Córdoba, Argentina.
| | - Nayla L Aliscioni
- Facultad de Ciencias Exactas, Físicas y Naturales, Instituto Multidisciplinario de Biología Vegetal (UNC-CONICET), Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, CC495, Córdoba, Argentina
| | - Marina Lorenzati
- Facultad de Ciencias Exactas, Físicas y Naturales, Instituto Multidisciplinario de Biología Vegetal (UNC-CONICET), Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, CC495, Córdoba, Argentina
| | - Sergio García
- Jardín Botánico Córdoba, Francisco Yunyent, 5491, Córdoba, Argentina
| | - Rodrigo B Singer
- Programa de Pós-Graduação em Botânica, Departamento de Botânica, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Porto Alegre, Rio Grande do Sul, 91501-970, Brazil
| | - Diego E Gurvich
- Facultad de Ciencias Exactas, Físicas y Naturales, Instituto Multidisciplinario de Biología Vegetal (UNC-CONICET), Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, CC495, Córdoba, Argentina.
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Martínez-Ramos LM, Vázquez-Santana S, García-Franco J, Mandujano MC. Is self-incompatibility a reproductive barrier for hybridization in a sympatric species? AMERICAN JOURNAL OF BOTANY 2024; 111:e16309. [PMID: 38584339 DOI: 10.1002/ajb2.16309] [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: 04/13/2023] [Revised: 01/29/2024] [Accepted: 01/29/2024] [Indexed: 04/09/2024]
Abstract
PREMISE Barriers at different reproductive stages contribute to reproductive isolation. Self-incompatibility (SI) systems that prevent self-pollination could also act to control interspecific pollination and contribute to reproductive isolation, preventing hybridization. Here we evaluated whether SI contributes to reproductive isolation among four co-occurring Opuntia species that flower at similar times and may hybridize with each other. METHODS We assessed whether Opuntia cantabrigiensis, O. robusta, O. streptacantha, and O. tomentosa, were self-compatible and formed hybrid seeds in five manipulation treatments to achieve self-pollination, intraspecific cross-pollination, open pollination (control), interspecific crosses or apomixis, then recorded flowering phenology and synchrony. RESULTS All species flowered in the spring with a degree of synchrony, so that two pairs of species were predisposed to interspecific pollination (O. cantabrigiensis with O. robusta, O. streptacantha with O. tomentosa). All species had distinct reproductive systems: Opuntia cantabrigiensis is self-incompatible and did not produce hybrid seeds as an interspecific pollen recipient; O. robusta is a dioecious species, which formed a low proportion of hybrid seeds; O. streptacantha and O. tomentosa are self-compatible and produced hybrid seeds. CONCLUSIONS Opuntia cantabrigiensis had a strong pollen-pistil barrier, likely due to its self-incompatibility. Opuntia robusta, the dioecious species, is an obligate outcrosser and probably partially lost its ability to prevent interspecific pollen germination. Given that the self-compatible species can set hybrid seeds, we conclude that pollen-pistil interaction and high flowering synchrony represent weak barriers; whether reproductive isolation occurs later in their life cycle (e.g., germination or seedling survival) needs to be determined.
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Affiliation(s)
- Linda M Martínez-Ramos
- Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México (UNAM), Unidad de Posgrado, Edificio A, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Ciudad de México, México
| | - Sonia Vázquez-Santana
- Laboratorio de Desarrollo en Plantas, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
| | - José García-Franco
- Instituto de Ecología A. C. Red de Ecología Funcional, Carretera antigua a Coatepec 351, El Haya, Xalapa, Veracruz, México
| | - María C Mandujano
- Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México
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Ramanauskas K, Igić B. RNase-based self-incompatibility in cacti. THE NEW PHYTOLOGIST 2021; 231:2039-2049. [PMID: 34101188 DOI: 10.1111/nph.17541] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/28/2021] [Indexed: 06/12/2023]
Abstract
Approximately one-half of all flowering plants express genetically based physiological mechanisms that prevent self-fertilisation. One such mechanism, termed RNase-based self-incompatibility, employs ribonucleases as the pistil component. Although it is widespread, it has only been characterised in a handful of distantly related families, partly due to the difficulties presented by life history traits of many plants, which complicate genetic research. Many species in the cactus family are known to express self-incompatibility but the underlying mechanisms remain unknown. We demonstrate the utility of a candidate-based RNA-seq approach, combined with some unusual features of self-incompatibility-causing genes, which we use to uncover the genetic basis of the underlying mechanisms. Specifically, we assembled transcriptomes from Schlumbergera truncata (crab cactus or false Christmas cactus), and interrogated them for tissue-specific expression of candidate genes, structural characteristics, correlation with expressed phenotype(s), and phylogenetic placement. The results were consistent with operation of the RNase-based self-incompatibility mechanism in Cactaceae. The finding yields additional evidence that the ancestor of nearly all eudicots possessed RNase-based self-incompatibility, as well as a clear path to better conservation practices for one of the most charismatic plant families.
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Affiliation(s)
- Karolis Ramanauskas
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Il, 60607, USA
| | - Boris Igić
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Il, 60607, USA
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Guerrero PC, Majure LC, Cornejo-Romero A, Hernández-Hernández T. Phylogenetic Relationships and Evolutionary Trends in the Cactus Family. J Hered 2020; 110:4-21. [PMID: 30476167 DOI: 10.1093/jhered/esy064] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/21/2018] [Indexed: 12/29/2022] Open
Abstract
Members of the cactus family are keystone species of arid and semiarid biomes in the Americas, as they provide shelter and resources to support other members of ecosystems. Extraordinary examples are the several species of flies of the genus Drosophila that lay eggs and feed in their rotting stems, which provide a model system for studying evolutionary processes. Although there is significant progress in understanding the evolution of Drosophila species, there are gaps in our knowledge about the cactus lineages hosting them. Here, we review the current knowledge about the evolution of Cactaceae, focusing on phylogenetic relationships and trends revealed by the study of DNA sequence data. During the last several decades, the availability of molecular phylogenies has considerably increased our understanding of the relationships, biogeography, and evolution of traits in the family. Remarkably, although succulent cacti have very low growth rates and long generation times, they underwent some of the fastest diversifications observed in the plant kingdom, possibly fostered by strong ecological interactions. We have a better understanding of the reproductive biology, population structure and speciation mechanisms in different clades. The recent publication of complete genomes for some species has revealed the importance of phenomena such as incomplete lineage sorting. Hybridization and polyploidization are common in the family, and have been studied using a variety of phylogenetic methods. We discuss potential future avenues for research in Cactaceae, emphasizing the need of a concerted effort among scientists in the Americas, together with the analyses of data from novel sequencing techniques.
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Affiliation(s)
- Pablo C Guerrero
- Departamento de Botánica, Universidad de Concepción, Chile, Concepción, Chile
| | - Lucas C Majure
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ.,Florida Museum of Natural History, University of Florida, Gainesville, FL
| | - Amelia Cornejo-Romero
- Departamento de Botánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
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Guerrero PC, Antinao CA, Vergara-Meriño B, Villagra CA, Carvallo GO. Bees may drive the reproduction of four sympatric cacti in a vanishing coastal mediterranean-type ecosystem. PeerJ 2019; 7:e7865. [PMID: 31608183 PMCID: PMC6786246 DOI: 10.7717/peerj.7865] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 09/10/2019] [Indexed: 11/20/2022] Open
Abstract
Background Sympatric congeneric plants might share pollinators, or each species might avoid competition by evolving specialized traits that generate partitions in pollinator assemblages. In both cases, pollen limitation (a decrease in the quality and quantity of compatible reproductive pollen) can occur, driving the plant mating system to autogamy as a mechanism of reproductive assurance. We assessed the relationships between pollinator assemblages and mating systems in a group of sympatric congeneric plants. We attempted to answer the following questions: (i) How similar are pollinator assemblages among sympatric cactus species? (ii) Which mating systems do sympatric cactus species use? Methods We studied sympatric Eriosyce taxa that inhabit a threatened coastal strip in a mediterranean-type ecosystem in central Chile. We performed field observations on four taxa and characterized pollinators during the years 2016 and 2017. We estimated differences in the pollinator assemblages using the Bray-Curtis index. To elucidate the mating systems, we conducted hand-pollination experiments using three treatments: manual cross-pollination, automatic self-pollination, and control (unmanipulated individuals). We tested differences in seed production for statistical significance using Kruskal-Wallis analysis. Results Eriosyce subgibbosa showed a distinctive pollinator assemblage among the sympatric species that we studied (similarity ranged from 0% to 8%); it was visited by small bees and was the only species that was visited by the giant hummingbird Patagona gigas. Pollinator assemblages were similar between E. chilensis (year 2016 = 4 species; 2017 = 8) and E. chilensis var. albidiflora (2016 = 7; 2017 = 4); however, those of E. curvispina var. mutabilis (2016 = 7; 2017 = 6) were less similar to those of the aforementioned species. E. curvispina var. mutabilis showed the highest interannual variation in its pollinator assemblage (18% similarity). Reproduction in E. subgibbosa largely depends on pollinators, although it showed some degree of autogamy. Autonomous pollination was unfeasible in E. chilensis, which depended on flower visitors for its reproductive success. Both E. chilensis var. albidiflora and E. curvispina var. mutabilis showed some degree of autogamy. Discussion We observed differences in pollinator assemblages between E. subgibbosa and the remaining Eriosyce taxa, which depend on hymenopterans for pollen transfer. Pollinator assemblages showed considerable interannual variation, especially those of E. subgibbosa (ornithophilous syndrome) and E. curvispina var. mutabilis (melitophilous syndrome). Autogamous reproduction in these taxa may act as a reproductive assurance mechanism when pollinator availability is unpredictable. Our study contributes to improving our understanding of the reproductive systems of ecological interactions between threatened species in a Chilean mediterranean-type ecosystem.
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Affiliation(s)
- Pablo C Guerrero
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Claudia A Antinao
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Beatriz Vergara-Meriño
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Cristian A Villagra
- Instituto de Entomología, Universidad Metropolitana de Ciencias de la Educación, Santiago, Chile
| | - Gastón O Carvallo
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
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Cerceau I, Siriani-Oliveira S, Dutra AL, Oliveira R, Schlindwein C. The cost of fidelity: foraging oligolectic bees gather huge amounts of pollen in a highly specialized cactus–pollinator association. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz083] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Plant–pollinator interactions vary along a specialization–generalization continuum. Advances in understanding the evolutionary and ecological consequences of different degrees of specialization depend on precise data on plant–pollinator interdependency. We studied the association of Parodia neohorstii (Cactaceae) and its bee pollinators focusing on pollinator foraging behaviour, flower functioning, female and male reproductive success, and pollen fate. Parodia neohorstii showed synchronized flower opening and pollen presentation but discontinuous blooming. The apparently generalized flowers partition pollen through thigmonastic stamen movements that function as a mechanical filter against generalist bees by restricting access to the major pollen reservoir to bees that show flower handling ‘know-how’, thereby favouring the oligolectic bee Arhysosage cactorum. This pollinator adjusted its pollen foraging to flower opening, removed pollen hurriedly, and promoted maximal fruit and seed set, which was minimal in its absence. Estimates of pollen fate revealed that a huge amount of pollen flows to specialized pollinators (86.5%), and only 0.9% reaches conspecific stigmas. The specialized interaction between P. neohorstii and Arhysosage cactorum, both threatened species, is efficient but fragile. Any environmental modification that causes a mismatch between the partners is likely to result in reproductive failure.
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Affiliation(s)
- Isabelle Cerceau
- Programa de Pós-Graduação em Biologia Vegetal, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Samuel Siriani-Oliveira
- Programa de Pós-Graduação em Biologia Vegetal, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Ana Laura Dutra
- Programa de Pós-Graduação em Ecologia, Conservação e Manejo da Vida Silvestre, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Reisla Oliveira
- Instituto de Ciências Biológicas, Departamento de Genética, Ecologia e Evolução, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Clemens Schlindwein
- Instituto de Ciências Biológicas, Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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