Local dispersal pathways during the invasion of the cactus moth, Cactoblastis cactorum, within North America and the Caribbean

Cactoblastis cactorum, a species of moth native to Argentina, feeds on several prickly pear cactus species (Opuntia) and has been successfully used as a biological control of invading Opuntia species in Australia, South Africa and native ruderal Opuntia species in some Caribbean islands. Since its introduction to the Caribbean its spread was uncontrolled, invading successfully Florida, Texas and Louisiana. Despite this long history of invasion, we are still far from understanding the factors determining the patterns of invasion of Cactoblastis in North America. Here, we explored three non-mutually exclusive explanations: a) a stepping stone model of colonization, b) long distance colonization due to hurricanes, and/or c) hitchhiking through previously reported commercial routes. Genetic diversity, genetic structure and the patterns of migration among populations were obtained by analyzing 10 nuclear microsatellite loci. Results revealed the presence of genetic structure among populations of C. cactorum in the invaded region and suggest that both marine commercial trade between the Caribbean islands and continental USA, as well as recurrent transport by hurricanes, explain the observed patterns of colonization. Provided that sanitary regulations avoiding humanmediated dispersal are enforced, hurricanes probably represent the most important agent of dispersal and future invasion to continental areas.Fil: Andraca Gómez, Guadalupe. Universidad Nacional Autónoma de México. Instituto de Ecología; MéxicoFil: Lombaert, Eric. Université Côte d'Azur; Francia. Centre National de la Recherche Scientifique; FranciaFil: Ordano, Mariano Andrés. Fundación Miguel Lillo; Argentina. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Pérez Ishiwara, Rubén. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; MéxicoFil: Boege, Karina. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; MéxicoFil: Domínguez, César A.. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; MéxicoFil: Fornoni, Juan. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; Méxic

Un viaje cuaternario por el desierto: El vulcanismo más que las oscilaciones climáticas explican los patrones filogeográficos compartidos entre especies de plantas ecológicamente distintas en La Payunia

Los patrones filogeográficos compartidos dentro de una comunidad vegetal conformada por especies ecológicamente distintas, pueden reflejar el rol preponderante de eventos geo-climáticos pasados que marcaron su historia evolutiva. Aunque las glaciaciones cuaternarias son los procesos más evocados como motores de estos patrones compartidos, en algunas regiones la actividad volcánica también debe considerarse como un proceso potencial que configuró la diversidad y distribución genética. Por otro lado, los atributos fenotípicos relacionados con la dispersión y la persistencia de las especies pueden modular el tiempo y el modo de la respuesta a estos cambios. Realizamos un estudio de filogeografía comparada entre cinco especies endémicas del Distrito patagónico de La Payunia para evaluar si sus patrones filogeográficos reflejan el impacto de los cambios climáticos versus el vulcanismo, teniendo en cuenta la influencia de sus hábitos y mecanismos de dispersión. Secuenciamos regiones no codificantes del ADN cloroplastidial, realizamos análisis genealógicos, de tiempo de divergencia, demográficos y de expansión de rango, y utilizamos cálculos bayesianos aproximados para comparar escenarios filogeográficos entre las especies. Las áreas climáticamente estables durante el último máximo glacial (UGM) se infirieron con modelos de distribución. Los resultados muestran un quiebre genético compartido entre las especies a los 37.5°S, siendo las poblaciones del norte menos diversas genéticamente, habitando áreas climáticamente estables e inestables, pero severamente afectadas por la actividad volcánica del Plio-Pleistoceno; las poblaciones del sur, donde el vulcanismo fue escaso/nulo, aparecen genéticamente más diversas y ocupan áreas climáticamente estables a través del tiempo. Las expansiones de rango y el aumento del tamaño efectivo de la poblaciones, ocurrieron después de la mayoría de los episodios volcánicos, y antes y durante el UMG. Todas las especies comparten el mismo origen geográfico de las expansiones. Asimismo, los arbustos muestran mayor diversidad genética en áreas ambientalmente estables, mientras que las especies con dispersión a larga distancia mostraron una mayor diversidad genética en áreas ambientalmente inestables. Los patrones genéticos a escala geográfica son consistentes con la influencia de eventos volcánicos, pero también mostraron una influencia basada en rasgos: los mecanismos de dispersión influirían en la colonización de áreas muy afectadas por cambios geo-climáticos, mientras que el tipo de forma de vida influiría en su persistencia en estas áreas. Estos resultados sugieren que el vulcanismo del cuaternario, en lugar de las oscilaciones climáticas, habría tenido un mayor efecto en la historia evolutiva de esta comunidad xerofítica, así como los rasgos auto-ecológicos habrían modulado la respuesta de la comunidad.Fil: Baranzelli, Matias Cristian. Universidad Nacional Autónoma de México. Departamento de Ecología Evolutiva. Instituto de Ecología; México. 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; ArgentinaFil: Cosacov Martinez, Andrea. 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; ArgentinaFil: Rocamundi, Nicolás. 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; ArgentinaFil: Issaly, Eduardo Andrés. 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; ArgentinaFil: Aguilar, Dana Lucia. 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; ArgentinaFil: Camps, Gonzalo Andres. 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; ArgentinaFil: Andraca Gómez, Guadalupe. Universidad Nacional Autónoma de México. Departamento de Ecología Evolutiva. Instituto de Ecología; MéxicoFil: Petrinovic, Ivan Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Johnson, Leigh Alma. No especifíca;Fil: Sérsic, Alicia Noemí. 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; ArgentinaIII Reunion Argentina de Biología EvolutivaBuenos AiresArgentinaUniversidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturale

Residual Effects of Transgenic Cotton on the Intestinal Microbiota of Dysdercus concinnus

The interaction among plants, insects, and microbes (PIM) is a determinant factor for the assembly and functioning of natural and anthropic ecosystems. In agroecosystems, the relationships among PIM are based on the interacting taxa, environmental conditions, and agricultural management, including genetically modified (GM) organisms. Although evidence for the unintended effects of GM plants on non-target insects is increasingly robust, our knowledge remains limited regarding their impact on gut microbes and their repercussions on the host’s ecology, especially in the wild. In this study, we compared the gut microbial community of Dysdercus concinnus bugs collected on wild cotton (Gossypium hirsutum), with and without insecticidal transgenes (cry1ab/ac), in its center of origin and diversity. By sequencing the V4–V5 region of 16S rRNA, we show differences in the diversity, structure, and topology of D. concinnus gut microbial interactions between specimens foraging cotton plants with and without transgenes. Identifying unintended residual effects of genetic engineering in natural ecosystems will provide first-line knowledge for informed decision-making to manage genetic, ecological, and evolutionary resources. Thus, determining which organisms interact with GM plants and how is the first step toward conserving natural ecosystems with evidence of transgenic introgression

Residual Effects of Transgenic Cotton on the Intestinal Microbiota of <i>Dysdercus concinnus</i>

The interaction among plants, insects, and microbes (PIM) is a determinant factor for the assembly and functioning of natural and anthropic ecosystems. In agroecosystems, the relationships among PIM are based on the interacting taxa, environmental conditions, and agricultural management, including genetically modified (GM) organisms. Although evidence for the unintended effects of GM plants on non-target insects is increasingly robust, our knowledge remains limited regarding their impact on gut microbes and their repercussions on the host’s ecology, especially in the wild. In this study, we compared the gut microbial community of Dysdercus concinnus bugs collected on wild cotton (Gossypium hirsutum), with and without insecticidal transgenes (cry1ab/ac), in its center of origin and diversity. By sequencing the V4–V5 region of 16S rRNA, we show differences in the diversity, structure, and topology of D. concinnus gut microbial interactions between specimens foraging cotton plants with and without transgenes. Identifying unintended residual effects of genetic engineering in natural ecosystems will provide first-line knowledge for informed decision-making to manage genetic, ecological, and evolutionary resources. Thus, determining which organisms interact with GM plants and how is the first step toward conserving natural ecosystems with evidence of transgenic introgression

A potential invasion route of Cactoblastis cactorum within the Caribbean region matches historical hurricane trajectories

The cactus moth, Cactoblastis cactorum mainly distributed throughout central and northeastern Argentina was intentionally introduced in the Caribbean region in 1957 as a biological control agent of cacti species of the genus Opuntia. This moth invaded during the last 20–30 years the North American continent, threatening the major center of biodiversity of native Opuntia species. Although human induced and natural dispersal have been invocated to explain its expansion in the non-native distribution range, there is still no evidence to support natural dispersal. In particular, hurricanes are one of the major environmental factors affecting species dispersal in the region. In this study we used mitochondrial DNA to examine whether the spatial distribution of haplotype variation of C. cactorum is at least partially explained by hurricane trajectories within the Caribbean region. DNA sequences for the mitochondrial gene cytochrome oxidase I were obtained for a sample of 110 individuals from the Antillean islands. This information was combined with existing sequences in the GenBank for the same gene for the Caribbean and Florida (N = 132 sequences). Genetic diversity descriptors, a haplotypic network, a spatial analyses of molecular variance and a landscape genetic analysis of migration conditioned by hurricane tracks were conducted to test our hypothesis. Our results revealed a significant spatial grouping of haplotypes consistent with the more frequent hurricane trajectories in the Caribbean region. Significant isolation by distance conditioned by hurricane tracks was detected. Populations of Florida were genetically closer to those of Cuba than to the rest of the population sampled. Within the region, Cuba appears as a reservoir of genetic diversity increasing the risk of invasion to Mexico and the US. Despite commercial transportation of Opuntia promoted dispersal to Florida, our results support the hypothesis that natural disturbances such as hurricanes played a role dispersing this invasive insect. Future conservation programs of North American Opuntia species requires taking into account hurricane mediated dispersal events and permanent whole regional monitoring and international control policies to prevent future range expansions of C. cactorum.Fil: Andraca Gómez, Guadalupe. Universidad Nacional Autónoma de México; MéxicoFil: Ordano, Mariano Andrés. Fundación Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Boege, Karina. Universidad Nacional Autónoma de México; MéxicoFil: Domínguez, César A.. Universidad Nacional Autónoma de México; MéxicoFil: Piñero, Daniel. Universidad Nacional Autónoma de México; MéxicoFil: Pérez Ishiwara, Rubén. Universidad Nacional Autónoma de México; MéxicoFil: Pérez Camacho, Jacqueline. Ministerio de Ciencia, Tecnología y Medio Ambiente. Instituto de Ecología y Sistemática; CubaFil: Cañizares, Maikel. Ministerio de Ciencia, Tecnología y Medio Ambiente. Instituto de Ecología y Sistemática; CubaFil: Fornoni, Juan. Universidad Nacional Autónoma de México; Méxic

Volcanism rather than climatic oscillations explains the shared phylogeographic patterns among ecologically distinct plant species in the southernmost areas of the South American Arid Diagonal

Shared genetic patterns within a community of ecologically distinct species may reflect the role of past geoclimatic events imprinting species evolutionary history. Although Pleistocene glaciations are the most important processes evoked as drivers of these shared patterns, in some regions Quaternary volcanic activity should also be considered as a potential process shaping genetic diversity distribution. Additionally, phenotypic attributes related to dispersal and persistence may affect the time and manner in which species respond to geoclimatic changes. We performed a comparative phylogeographical study within a plant community of the South American Arid Diagonal to assess whether genetic patterns are better explained by climatic changes or volcanisms, taking into account the possible influence of life form and dispersal syndromes of the focal species. Chloroplast intergenic spacers were sequenced for five plant species. Genealogy, divergence time estimates, demographic and range expansion analyses were performed. Approximate Bayesian Computation was used to test plausible shared phylogeographic scenarios. Climatically stable areas during the last glacial period were inferred with distribution modeling. Results showed that most species were split into northern and southern lineages separated by a phylogeographic break at around 37.5 °S, with the northern populations being genetically less diverse, inhabiting both climatically stable and unstable areas, but being severely affected by intense Plio-Pleistocene magmatic activity; the southern populations, less influenced by volcanism, appeared to be genetically more diverse and occupied climatically stable areas through time. Most recent range expansions and effective population size increases occurred after most of the volcanic episodes, before and during the Last Glacial Maximum. All species shared the same geographic origin of the detected spatial expansion. Overall, our results suggest a preponderant effect of Quaternary volcanism rather than climatic oscillations on the evolutionary history of this xerophytic community. Additionally, we found evidence that autecological traits would have modulated the community historical responses.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Baranzelli, Matias Cristian. 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. Universidad Nacional Autónoma de México. Instituto de Ecología; MéxicoFil: Cosacov Martinez, Andrea. 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; ArgentinaFil: Rocamundi, Nicolás. 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; ArgentinaFil: Issaly, Eduardo Andrés. 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; ArgentinaFil: Aguilar, Dana Lucía. 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; ArgentinaFil: Camps, Gonzalo Andres. 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. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Andraca-Gómez, Guadalupe. Universidad Nacional Autónoma de México. Instituto de Ecología; MéxicoFil: Petrinovic, Ivan Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Johnson, Leigh, A. Brigham Young University. Department of Biology and M. L. Bean Life Science Museum; Estados UnidosFil: 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; Argentin

Adaptive divergence in resistance to herbivores in Datura stramonium

Defensive traits exhibited by plants vary widely across populations. Heritable phenotypic differentiation is likely to be produced by genetic drift and spatially restricted gene flow between populations. However, spatially variable selection exerted by herbivores may also give rise to differences among populations. To explore to what extent these factors promote the among-population differentiation of plant resistance of 13 populations of Datura stramonium, we compared the degree of phenotypic differentiation (PST) of leaf resistance traits (trichome density, atropine and scopolamine concentration) against neutral genetic differentiation (FST) at microsatellite loci. Results showed that phenotypic differentiation in defensive traits among-population is not consistent with divergence promoted by genetic drift and restricted gene flow alone. Phenotypic differentiation in scopolamine concentration was significantly higher than FST across the range of trait heritability values. In contrast, genetic differentiation in trichome density was different from FST only when heritability was very low. On the other hand, differentiation in atropine concentration differed from the neutral expectation when heritability was less than or equal to 0.3. In addition, we did not find a significant correlation between pair-wise neutral genetic distances and distances of phenotypic resistance traits. Our findings reinforce previous evidence that divergent natural selection exerted by herbivores has promoted the among-population phenotypic differentiation of defensive traits in D. stramonium