Abstract:

We studied gland morphology, anatomy and the chemical composition of the floral fragrance in the sweat bee-pollinated orchid Cyclopogon elatus.This is apparently the first such analysis for any Cyclopogon species, and one of very few studies in which both odour and osmophore are characterised in a nectar-rewarding orchid. Structures responsible for floral scent production were localised with neutral red staining and histochemical assays for lipids and starch. Their morphology and anatomy were studied with scanning electron microscopy and light microscopy thin sections, respectively. Fragrance samples were collected using SPME fibres and analysed with GC-MS. Anatomical evidence suggests that two parallel oval-shaped patches of unicellular trichomes on the abaxial surface of the labellum are osmophores. These are rich in stored lipids, while the parenchyma surrounding the vascular bundles contains starch. Only freshly opened flowers produced odours, while buds and withered flowers lacked scent. The chemical composition of the odour was dominated (>99.8%) by a single compound, trans-4,8-dimethyl-nona-1,3,7-triene (DMNT). Gland anatomy and position on the outside of the perianth are unusual for scent glands in general. The presence of DMNT, a nearly ubiquitous compound in herbivoreinduced vegetative emissions and one of the major floral volatiles of Yucca, is not surprising in view of hypotheses on the evolutionary origin of flower scents, suggesting that wound volatiles are utilised as kairomonal attractants by florivores whose activities result in pollination.

Author affiliation: Wiemer, Ana Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Raguso, R. A.. University of South Carolina; Estados Unidos. Cornell University; Estados Unidos

Author affiliation: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Abstract:

Some species of long-spurred orchids achieve pollination by a close association with long-tongued hawkmoths. Among them, several Habenaria species present specialized mechanisms, where pollination success depends on the attachment of pollinaria onto the heads of hawkmoths with very long proboscises. However, in the Neotropical region such moths are less abundant than their shorter-tongued relatives and are also prone to population fluctuations. Both factors may give rise to differences in pollinator-mediated selection on floral traits through time and space.

Author affiliation: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Amorim, Felipe W.. Universidade Estadual de Campinas, Campinas. Instituto de Biologia. Departamento de Biologia Vegetal. Programa de Pós-Graduação em Biologia Vegetal; Brasil

Author affiliation: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Medina, Arnaldo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Sazima, Marlies. Universidade Estadual de Campinas. Instituto de Biologia. Departamento de Biologia Vegetal; Brasil

Author affiliation: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Abstract:

1. A major challenge in evolutionary ecology is to understand how co-evolutionary processes shape patterns of interactions between species at community level. Pollination of flowers with long corolla tubes by long-tongued hawkmoths has been invoked as a showcase model of co-evolution. Recently, optimal foraging models have predicted that there might be a closeassociation between mouthparts? length and the corolla depth of the visited flowers, thus favouring trait convergence and specialization at community level.2. Here, we assessed whether hawkmoths more frequently pollinate plants with floral tube lengths similar to their proboscis lengths (morphological match hypothesis) against abundance-based processes (neutral hypothesis) and ecological trait mismatches constraints (forbidden links hypothesis), in structuring hawkmoth?plant mutualistic networks from five communities in four biogeographical regions of South America.3. We found convergence in morphological traits across the five communities and that the distribution of morphological differences between hawkmoths and plants is consistent with expectations under the morphological match hypothesis in three of the five communities. In the two remaining communities, which are ecotones between two distinct biogeographical areas, interactions are better predicted by the neutral hypothesis.4. Our findings are consistent with the idea that diffuse co-evolution drives the evolution of extremely long proboscises and flower tubes, and highlight the importance of morphological traits, beyond the forbidden links hypothesis, in structuring interactions between mutualistic partners, revealing that the role of niche-based processes can be much more complex than previously known.

Author affiliation: Sazatornil, Federico David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Kitching, Ian. Natural History Museum; Reino Unido

Author affiliation: Schlumpberger, Boris O.. Herrenhausen Gardens; Alemania

Author affiliation: Oliveira, Paulo E.. Universidade Federal de Uberlandia; Brasil

Author affiliation: Sazima, Marlies. Universidade Estadual de Campinas; Brasil

Author affiliation: Amorim, Felipe. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil

Abstract:

With the purpose of discussing the evolutionary dynamics of the karyotypes and their relationship with key geological events, CMA/DAPI banding and FISH techniques were applied to metaphase chromosomes of 13 Jaborosa species plus Sclerophylax spinescens, and the resulting characters were reconstructed onto a dated phylogenetic tree. Jaborosa presents a distinctive evolutionary pathway at the chromosomal level in respect to its sister clades, the Hyoscyameae, Lycium and Sclerophylax. The divergence of the common ancestor of Jaborosa involved an increase in chromosome size, with a slight rise in the amount of heterochromatin and chromosomal asymmetry, all these changes taking place at the diploid level. Variation in the number and position of rDNA sites showed profuse chromosomal rearrangements, such as duplications and transpositions. Contrasting evolution of the 5S and 18-5.8-26S rDNA seems to have occurred, with the 5S site being more stable than the 18-5.8-26S. The diversification of Jaborosa seems to be correlated with the most recent uplifts in the Andes in central South America and the establishment of the Patagonian steppe: the genus colonized these biomes and at the same time underwent a remarkable chromosomal and morphological differentiation. Although some characters were seen to be homoplastic, the combination of chromosome markers employed here allowed species discrimination.

Author affiliation: Chiarini, Franco Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Moreno, Natalia Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Barboza, Gloria Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Abstract:

Background and aims: A South American cactus species, Echinopsis ancistrophora (Cactaceae), with dramatic among-population variation in floral traits is presented. Methods: Eleven populations of E. ancistrophora were studied in their habitats in northern Argentina, and comparisons were made of relevant floral traits such as depth, stigma position, nectar volume and sugar concentration, and anthesis time. Diurnal and nocturnal pollinator assemblages were evaluated for populations with different floral trait combinations. Key Results: Remarkable geographical variations in floral traits were recorded among the 11 populations throughout the distribution range of E. ancistrophora, with flower lengths ranging from 4.5 to 24.1 cm. Other floral traits associated with pollinator attraction also varied in a population-specific manner, in concert with floral depth. Populations with the shortest flowers showed morning anthesis and those with the longest flowers opened at dusk, whereas those with flowers of intermediate length opened at unusual times (2300–0600 h). Nectar production varied non-linearly with floral length; it was absent to low (population means up to 15 mL) in short- to intermediate-length flowers, but was high (population means up to 170 mL) in the longest tubed flowers. Evidence from light-trapping of moths, pollen carriage on their bodies and moth scale deposition on stigmas suggests that sphingid pollination is prevalent only in the four populations with the longest flowers, in which floral morphological traits and nectar volumes match the classic expectations for the hawkmoth pollination syndrome. All other populations, with flowers 4.5–15 cm long, were pollinated exclusively by solitary bees. Conclusions: The results suggest incipient differentiation at the population level and local adaptation to either bee or hawkmoth (potentially plus bee) pollination.

Author affiliation: Schlumpberger, Boris O.. Ludwig Maximilians Universitat; Alemania

Author affiliation: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Raguso, Robert A.. Cornell University; Estados Unidos

Abstract:

The genus Jaborosa (Solanaceae), which comprises 22 species endemic to southern South America, encompasses remarkable flower variation. To test if this interspecific variation is related to transitions in pollination mode and to major concomitant geological changes, phylogenetic relationships within the genus were reconstructed. To determine when such major transitions in flower traits occurred, divergence times were estimated and the evolution of relevant floral traits was studied. Sequences of four plastid spacer regions (trnH-pbsA, trnDGUC -trnTGGU , rpl32-trnLUAG , ndhF-rpl32) and one nuclear region (granule-bound starch synthase) were used to resolve relationships among 18 Jaborosa species, using species of the “Atropina clade” as outgroup. Phylogenetic reconstruction strongly supports the monophyly of Jaborosa, with species resolved in two major clades: (1) a “Lowland clade” (L) comprised of three noticeably sphingophylous species distributed below 1000 m and north of 36° S latitude, and (2) an “Andean clade” (A) composed of the remaining species, which strongly differ in floral morphology and mainly occur at high altitudes (more than 3000 m in the Puna desert) or high latitudes (up to 53° S latitude in the Patagonia steppe of Tierra del Fuego). Species in the Andean clade have flowers that range from black, rotate, deceptive, saprophilous fly-pollinated flowers to green, tubular, nectar-producing flowers with a mixed pollination system. Estimation of divergence times suggests a split of Jaborosa from its sister genus Atropa L. at ca. 16.7 Ma. The split between the L and A clades possibly occurred ca. 10 Ma, with recent species diversification co-occurring with the uplift of the Andes during the Pleistocene (ca. 1–3 Ma). Reconstruction of ancestral states of pollination mode, altitudinal distribution, and floral traits (corolla colour, flower morphology, presence of nectar) suggests that pollination by moths probably evolved once within the L clade, whereas brood-site deceptive pollination probably evolved once within the A clade. These contrasting pollination modes are associated with changes in corolla colour, flower morphology and loss of a functional nectary.

Author affiliation: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Author affiliation: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Author affiliation: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Author affiliation: Barboza, Gloria Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Abstract:

Patrones de depósito de polen sobre el cuerpo de los polinizadores en comunidades esfingófilas de Argentina Subtropical. Las especies de plantas que coexisten y comparten agentes polinizadores pueden experimentar competencia interespecífica por el servicio de los polinizadores o por interferencia de polen impropio. Para evitar esto último, las especies de plantas pueden utilizar diferentes sitios del cuerpo de los polinizadores para depositar su polen, ya sea mediante diferentes arquitecturas florales o diferentes longitudes florales. Evaluamos aquí la ocurrencia de este patrón de utilización diferencial de los cuerpos de los polinizadores en diferentes comunidades esfingófilas de Argentina Subtropical (i.e. si las plantas depositan el polen en diferentes partes del cuerpo o a diferentes alturas en la probóscide de los esfíngidos polinizadores). Hallamos que 42 especies de plantas nativas son polinizadas por esfíngidos en Argentina Subtropical. Observamos una correlación positiva y significativa entre la distancia operativa de las flores y la longitud media de la probóscide de los esfíngidos polinizadores. Sin embargo, tanto la diversidad promedio de los sitios de depósito de polen como la diferencia promedio de longitud floral entre especies de plantas esfingófilas presentes en la misma comunidad no difirieron significativamente de lo esperado bajo un modelo nulo, aunque nueve comunidades presentaron una alta diversidad de los sitios de depósito, la cual fue significativamente mayor que lla esperada por azar. Estos resultados sugieren que otros factores, como el grado de generalización en la polinización, la fenología y/o la utilización de señales florales distintivas, podrían estar evitando la competencia por polinizadores entre especies de plantas coexistentes.

Plant species that coexist and share pollinators may experience inter-specific competition for pollina­ tor service or interference of improper pollen. To avoid the latter, plant species may use different areas of the pollinators' body to deposit their pollen, either by different floral architectures or by different floral lengths. We evaluate here the existence of this pattem of differential use of body areas of pollinators in 33 sphingophilous communities of subtropical Argentina. We use null models to evaluate if the plants deposit the pollen overdispersed relative to what would be expected by chance either in different body parts or at different heights in the probaseis of hawkmoth pollinators. We found that 42 native plants species are pollinated by hawkmoths in subtropical Argentina. We observed a significant and positive correlation between the operative length -i.e. the distance between anthers and stigma from nectar- of the flowers and the mean length ofthe proboseis ofhawkmoth pollinators. However, both the average di­ versity of pollen deposition sites and the average difference of operative length between sphingophilous plant species present in the same community were not significantly different than expected under a null model. When analyzing the results in individual communities, nine communities showed a diversity of pollen deposition sites significantly higher than expected by chance and two communities showed a di­ fference in the operative length greater than expected by chance. These results suggest that other factors such as the degree of generalization in pollination, phenology and 1 or the use of distinctive floral signals may be avoiding competition for pollinators between coexisting plants species.

Author affiliation: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Author affiliation: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Author affiliation: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Author affiliation: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Abstract:

The genus Jaborosa (Solanaceae), which comprises 22 species endemic to southern South America, encompasses remarkable flower variation. To test if this interspecific variation is related to transitions in pollination mode and to major concomitant geological changes, phylogenetic relationships within the genus were reconstructed. To determine when such major transitions in flower traits occurred, divergence times were estimated and the evolution of relevant floral traits was studied. Sequences of four plastid spacer regions (trnH-pbsA, trnDGUC -trnTGGU , rpl32-trnLUAG , ndhF-rpl32) and one nuclear region (granule-bound starch synthase) were used to resolve relationships among 18 Jaborosa species, using species of the “Atropina clade” as outgroup. Phylogenetic reconstruction strongly supports the monophyly of Jaborosa, with species resolved in two major clades: (1) a “Lowland clade” (L) comprised of three noticeably sphingophylous species distributed below 1000 m and north of 36° S latitude, and (2) an “Andean clade” (A) composed of the remaining species, which strongly differ in floral morphology and mainly occur at high altitudes (more than 3000 m in the Puna desert) or high latitudes (up to 53° S latitude in the Patagonia steppe of Tierra del Fuego). Species in the Andean clade have flowers that range from black, rotate, deceptive, saprophilous fly-pollinated flowers to green, tubular, nectar-producing flowers with a mixed pollination system. Estimation of divergence times suggests a split of Jaborosa from its sister genus Atropa L. at ca. 16.7 Ma. The split between the L and A clades possibly occurred ca. 10 Ma, with recent species diversification co-occurring with the uplift of the Andes during the Pleistocene (ca. 1–3 Ma). Reconstruction of ancestral states of pollination mode, altitudinal distribution, and floral traits (corolla colour, flower morphology, presence of nectar) suggests that pollination by moths probably evolved once within the L clade, whereas brood-site deceptive pollination probably evolved once within the A clade. These contrasting pollination modes are associated with changes in corolla colour, flower morphology and loss of a functional nectary.

Author affiliation: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

Author affiliation: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba; Argentina

Author affiliation: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba; Argentina

Author affiliation: Barboza, Gloria Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba; Argentina

Abstract:

The putative ancestors of the allopolyploid hybrid Nicotiana tabacum have distinct flower features, apparently suited either for hawkmoth or bat pollination. This suggests that progenitors were reproductively isolated by mechanical and ethological barriers. However, the present data show that in natural populations pollen vectors could be shared by two of the possible progenitors. Pollen vectors of one of the possible male progenitors (N. otophora) were short- and long-tongued hawkmoths and a nectar-feeding bat, while those of the female ancestor (N. sylvestris) were only longtongued hawkmoths. The latter are then the most likely vectors responsible for the presumed spontaneous hybridization. These data also suggest that interspecific pollen transfer occurred more likely in one direction.

Author affiliation: Nattero, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Abstract:

The coevolutionary process among free-living mutualists with extremely long matching traits may favor the formation of mutualistic interaction networks through coevolutionary escalation, complementarity and convergence. These networks may be geographically structured; the links among the species of a local network are shaped by the biotic composition of the community, thus creating selection mosaics at broader geographical scales. Therefore, to fully understand a coevolutionary process, it is crucial to visualize the geographical structure of the interaction network across the landscape. In this study we focused on the poorly known interaction system between Ensifera ensifera and its guild of long-flowered plant species. We combined occurrence data and environmental variables to predict E. ensifera distribution, in addition to range polygons available for plant species in order to evaluate the geographical variation in bill length and plant species richness. A positive relationship between bill length and plant species richness within the E. ensifera range suggests a geographical structuring of the interaction networks. At mid-latitude locations of E. ensifera range, where hummingbirds attained the longest bills, richness of long-flowered plant species was higher than at low latitude locations. These locations likely represent coevolutionary vortices where long-lasting reciprocal selection probably drove the evolution of long traits, consequently drawing new plant species into the coevolutionary network. Conversely, areas where the sword-billed hummingbird was absent or had shorter bills probably represent coevolutionary coldspots. Our results provide a first insight into this phenotypically specialized plant-pollinator network across the landscape and show candidate areas to test the predictions of the coevolutionary hypothesis, such as reciprocal selection.

Author affiliation: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Moré, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Ibañez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Iglesias, María del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina