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Aranda-Rickert A, Torréns J, Yela NI, Brizuela MM, Di Stilio VS. Distance Dependent Contribution of Ants to Pollination but Not Defense in a Dioecious, Ambophilous Gymnosperm. Front Plant Sci 2021; 12:722405. [PMID: 34567036 PMCID: PMC8459830 DOI: 10.3389/fpls.2021.722405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
Dioecious plants are obligate outcrossers with separate male and female individuals, which can result in decreased seed set with increasing distance between the sexes. Wind pollination is a common correlate of dioecy, yet combined wind and insect pollination (ambophily) could be advantageous in compensating for decreased pollen flow to isolated females. Dioecious, ambophilous gymnosperms Ephedra (Gnetales) secrete pollination drops (PDs) in female cones that capture airborne pollen and attract ants that feed on them. Plant sugary secretions commonly reward ants in exchange for indirect plant defense against herbivores, and more rarely for pollination. We conducted field experiments to investigate whether ants are pollinators and/or plant defenders of South American Ephedra triandra, and whether their contribution to seed set and seed cone protection varies with distance between female and male plants. We quantified pollen flow in the wind and assessed the effectiveness of ants as pollinators by investigating their relative contribution to seed set, and their visitation rate in female plants at increasing distance from the nearest male. Ants accounted for most insect visits to female cones of E. triandra, where they consumed PDs, and pollen load was larger on bigger ants without reduction in pollen viability. While wind pollination was the main contributor to seed set overall, the relative contribution of ants was distance dependent. Ant contribution to seed set was not significant at shorter distances, yet at the farthest distance from the nearest male (23 m), where 20 times less pollen reached females, ants enhanced seed set by 30% compared to plants depending solely on wind pollination. We found no evidence that ants contribute to plant defense by preventing seed cone damage. Our results suggest that, despite their short-range movements, ants can offset pollen limitation in isolated females of wind-pollinated plants with separate sexes. We propose that ants enhance plant reproductive success via targeted delivery of airborne pollen, through frequent contact with ovule tips while consuming PDs. Our study constitutes the first experimental quantification of distance-dependent contribution of ants to pollination and provides a working hypothesis for ambophily in other dioecious plants lacking pollinator reward in male plants.
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Affiliation(s)
- Adriana Aranda-Rickert
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
| | - Javier Torréns
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
- Universidad Nacional de La Rioja, La Rioja, Argentina
| | - Natalia I. Yela
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
| | - María Magdalena Brizuela
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), Anillaco, Argentina
- Universidad Nacional de La Rioja, La Rioja, Argentina
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Miranda V, Sede S, Aranda-Rickert A, Rothen C, Scervino JM, Barros J, Fracchia S. Taxonomy, life cycle and endophytism of coprophilous fungi from an underground desert rodent. FUNGAL ECOL 2020. [DOI: 10.1016/j.funeco.2019.100872] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Miranda V, Rothen C, Yela N, Aranda-Rickert A, Barros J, Calcagno J, Fracchia S. Subterranean Desert Rodents (Genus Ctenomys) Create Soil Patches Enriched in Root Endophytic Fungal Propagules. Microb Ecol 2019; 77:451-459. [PMID: 30003276 DOI: 10.1007/s00248-018-1227-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
Subterranean rodents are considered major soil engineers, as they can locally modify soil properties by their burrowing activities. In this study, the effect of a subterranean rodent of the genus Ctenomys on soil properties and root endophytic fungal propagules in a shrub desert of northwest Argentina was examined. Our main goal was to include among root endophytic fungi not only arbuscular mycorrhiza but also the dark septate endophytes. We compared the abundance of fungal propagules as well as several microbiological and physicochemical parameters between soils from burrows and those from the surrounding landscape. Our results show that food haulage, the deposition of excretions, and soil mixing by rodents' burrowing promote soil patchiness by (1) the enrichment in both types of root endophytic fungal propagules; (2) the increase in organic matter and nutrients; and (3) changes in soil edaphic properties including moisture, field capacity, and texture. These patches may play a critical role as a source of soil heterogeneity in desert ecosystems, where burrows constructed in interpatches of bare soil can act, once abandoned, as "islands of fertility," promoting the establishment of plants in an otherwise hostile environment.
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Affiliation(s)
- Victoria Miranda
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET, Provincia de La Rioja, UNLAR, SEGEMAR, UNCa), Entre Ríos y Mendoza s/n, 5301, Anillaco La Rioja, Argentina.
| | - Carolina Rothen
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET, Provincia de La Rioja, UNLAR, SEGEMAR, UNCa), Entre Ríos y Mendoza s/n, 5301, Anillaco La Rioja, Argentina
| | - Natalia Yela
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET, Provincia de La Rioja, UNLAR, SEGEMAR, UNCa), Entre Ríos y Mendoza s/n, 5301, Anillaco La Rioja, Argentina
| | - Adriana Aranda-Rickert
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET, Provincia de La Rioja, UNLAR, SEGEMAR, UNCa), Entre Ríos y Mendoza s/n, 5301, Anillaco La Rioja, Argentina
| | - Johana Barros
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET, Provincia de La Rioja, UNLAR, SEGEMAR, UNCa), Entre Ríos y Mendoza s/n, 5301, Anillaco La Rioja, Argentina
| | - Javier Calcagno
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico (CEBBAD), Departamento de Ciencias Naturales y Antropológicas, CONICET, Buenos Aires, Argentina
| | - Sebastián Fracchia
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET, Provincia de La Rioja, UNLAR, SEGEMAR, UNCa), Entre Ríos y Mendoza s/n, 5301, Anillaco La Rioja, Argentina
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Aranda-Rickert A, Rothen C, Diez P, González AM, Marazzi B. Sugary secretions of wasp galls: a want-to-be extrafloral nectar? Ann Bot 2017; 120:765-774. [PMID: 28673028 PMCID: PMC5714234 DOI: 10.1093/aob/mcx075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 05/05/2017] [Accepted: 05/16/2017] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND AIMS The most widespread form of protective mutualisms is represented by plants bearing extrafloral nectaries (EFNs) that attract ants and other arthropods for indirect defence. Another, but less common, form of sugary secretion for indirect defence occurs in galls induced by cynipid wasps. Until now, such galls have been reported only for cynipid wasps that infest oak trees in the northern hemisphere. This study provides the first evidence of galls that exude sugary secretions in the southern hemisphere and asks whether they can be considered as analogues of plants' EFNs. METHODS The ecology and anatomy of galls and the chemical composition of the secretion were investigated in north-western Argentina, in natural populations of the host trees Prosopis chilensis and P. flexuosa . To examine whether ants protect the galls from natural enemies, ant exclusion experiments were conducted in the field. KEY RESULTS The galls produce large amounts of sucrose-rich, nectar-like secretions. No typical nectary and sub-nectary parenchymatic tissues or secretory trichomes can be observed; instead there is a dense vascularization with phloem elements reaching the gall periphery. At least six species of ants, but also vespid wasps, Diptera and Coleoptera, consumed the gall secretions. The ant exclusion experiment showed that when ants tended galls, no differences were found in the rate of successful emergence of gall wasps or in the rate of parasitism and inquiline infestation compared with ant-excluded galls. CONCLUSIONS The gall sugary secretion is not analogous to extrafloral nectar because no nectar-producing structure is associated with it, but is functionally equivalent to arthropod honeydew because it provides indirect defence to the plant parasite. As in other facultative mutualisms mediated by sugary secretions, the gall secretion triggers a complex multispecies interaction, in which the outcome of individual pair-wise interactions depends on the ecological context in which they take place.
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Affiliation(s)
- Adriana Aranda-Rickert
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR), Provincia de La Rioja, UNLaR, SEGEMAR, UNCa, CONICET, Entre Ríos y Mendoza s/n, CP 5301, Anillaco, La Rioja, Argentina
- For correspondence. E-mail
| | - Carolina Rothen
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR), Provincia de La Rioja, UNLaR, SEGEMAR, UNCa, CONICET, Entre Ríos y Mendoza s/n, CP 5301, Anillaco, La Rioja, Argentina
| | - Patricia Diez
- Centro de Investigaciones y Transferencia de Catamarca (CITCA), CONICET, UNCa, Prado 366, CP 4700, SFV de Catamarca, Catamarca, Argentina
| | - Ana María González
- Instituto de Botánica del Nordeste (IBONE), UNNE-CONICET. Facultad de Ciencias Agrarias, Sto. Cabral 2131, CP 3400, Corrientes, Argentina
| | - Brigitte Marazzi
- Natural Hisotry Museum of Canton Ticino, Viale C. Cattaneo 4, 6900 Lugano, Switzerland
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Abstract
Interactions mediated by extrafloral nectary (EFN)-bearing plants that reward ants with a sweet liquid secretion are well documented in temperate and tropical habitats. However, their distribution and abundance in deserts are poorly known. In this study, we test the predictions that biotic interactions between EFN plants and ants are abundant and common also in arid communities and that EFNs are only functional when new vegetative and reproductive structures are developing. In a seasonal desert of northwestern Argentina, we surveyed the richness and phenology of EFN plants and their associated ants and examined the patterns in ant-plant interaction networks. We found that 25 ant species and 11 EFN-bearing plant species were linked together through 96 pairs of associations. Plants bearing EFNs were abundant, representing ca. 19 % of the species encountered in transects and 24 % of the plant cover. Most ant species sampled (ca. 77 %) fed on EF nectar. Interactions showed a marked seasonal pattern: EFN secretion was directly related to plant phenology and correlated with the time of highest ant ground activity. Our results reveal that EFN-mediated interactions are ecologically relevant components of deserts, and that EFN-bearing plants are crucial for the survival of desert ant communities.
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Affiliation(s)
- Adriana Aranda-Rickert
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja-CRILAR-(CONICET), Entre Ríos y Mendoza s/n, 5301 Anillaco, La Rioja, Argentina
| | - Patricia Diez
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja-CRILAR-(CONICET), Entre Ríos y Mendoza s/n, 5301 Anillaco, La Rioja, Argentina
| | - Brigitte Marazzi
- Facultad de Ciencias Agrarias, Instituto de Botánica del Nordeste-IBONE-(UNNE-CONICET), Sgto. Cabral 2131, 3400 Corrientes, Argentina
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Fracchia S, Aranda-Rickert A, Flachsland E, Terada G, Sede S. Mycorrhizal compatibility and symbiotic reproduction of Gavilea australis, an endangered terrestrial orchid from south Patagonia. Mycorrhiza 2014; 24:627-34. [PMID: 24777596 DOI: 10.1007/s00572-014-0579-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 04/08/2014] [Indexed: 05/03/2023]
Abstract
Gavilea australis is a terrestrial orchid endemic from insular south Argentina and Chile. Meeting aspects of mycorrhizal fungi identity and compatibility in this orchid species is essential for propagation and conservation purposes. These knowledge represent also a first approach to elucidate the mycorrhizal specificity of this species. In order to evaluate both the mycorrhizal compatibility and the symbiotic seed germination of G. australis, we isolated and identified its root endophytic fungal strains as well as those from two sympatric species: Gavilea lutea and Codonorchis lessonii. In addition, we tested two other strains isolated from allopatric terrestrial orchid species from central Argentina. All fungal strains formed coilings and pelotons inside protocorms and promoted, at varying degrees, seed germination, and protocorm development until seedlings had two to three leaves. These results suggest a low mycorrhizal specificity of G. australis and contribute to a better knowledge of the biology of this orchid as well as of other sympatric Patagonian orchid species, all of them currently under serious risk of extinction.
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Affiliation(s)
- Sebastián Fracchia
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica, CRILAR-CONICET, Entre Ríos y Mendoza, 5301, Anillaco, La Rioja, Argentina,
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