Resumen Con el fin de evaluar la respuesta de la micropropagación de plantas de caña flecha, Gynerium sagittatum (Aubl.), en un medio en doble fase durante la etapa de multiplicación, se establecieron explantes (porciones de tallos con meristemos axilares) de los cultivares Criolla, Criolla 1 y Martinera en un medio semisólido in vitro y se multiplicaron en un medio en doble fase con adición de varias concentraciones de bencilaminopurina (BAP) (0,0mg/L, 0,5mg/L, 1,0mg/L, 1,5mg/L y 2,0mg/L). Luego, se realizó enraizamiento en un medio con varias concentraciones de ácido naftalenacético (ANA) (0,0mg/L, 0,5mg/L, 1,0mg/L, 1,5mg/L y 2,0mg/L). Tanto los tallos multiplicados sin enraizar como los enraizados in vitro se transfirieron ex vitro. Los tratamientos se distribuyeron con un diseño completo al azar, los datos se analizaron con ANOVA y las medias se separaron mediante la prueba de Tukey. Los microbrotes de los genotipos Criolla y Martinera cultivados con 0,5mg/L de BAP mostraron tasas de multiplicación significativamente superiores en comparación con los controles. Todos los microbrotes multiplicados y transferidos a un medio de enraizamiento formaron raíces, aunque el ANA aumentó significativamente el número de raíces y redujo su longitud. Los tallos multiplicados de los tres cultivares, con raíces o sin raíces, transferidos ex vitro mostraron una adaptación y supervivencia del 100%. Para Criolla y Martinera, los 0,5mg/L de BAP aumentaron estadísticamente la multiplicación. El ANA incrementó la formación de raíces adventicias y redujo su longitud. Las plantas de todos los cultivares se adaptaron a condiciones ex vitro en un 100%.

Abstract To evaluate the micropropagation response of arrow cane, Gynerium sagittatum (Aubl.), plants using a double-phase medium in the multiplication stage, explants consisting of stem sections with axillary meristems from cultivars Criolla, Criolla 1, and Martinera were established in vitro in a semisolid medium. Then, they were multiplied using a double-phase medium supplied at several Benzylaminopurine (BAP) concentrations (0.0, 0.5, 1.0, 1.5, and 2.0 mg/L), followed by rooting in a culture medium supplied at several Naphthaleneacetic acid (NAA) concentrations (0.0, 0.5, 1.0, 1.5, and 20 mg/L). Both multiplied unrooted and rooted microshoots were transferred ex vitro. Treatments were distributed with a completely randomized design; data were analyzed with an ANOVA and means separated with Tukey’s test. Explants from Criolla and Martinera cultured with 0.5 mg/L BAP resulted in higher multiplication rates. All microshoots transferred to the rooting medium rooted, although NAA significantly increased the number of roots and reduced root length. Plants from all three cultivars, in vitro rooted or unrooted that were transferred to ex vitro conditions showed 100% survival and adaptation. For Criolla and Martinera, 0.5 mg/L BAP statistically increased shoot multiplication rates and NAA increased adventitious root formation and reduced root length. Plants of all cultivars survived and adapted 100% to ex vitro conditions.

Resumen Introducción: La fibra de Gynerium sagittatum Aubl. P. Beauv, es materia prima esencial para la elaboración de varias artesanías, que son símbolos de la identidad cultural colombiana. En el proceso de fabricación, se utilizan diferentes genotipos de acuerdo con la calidad de la fibra y el tipo de artesanía, pero se cree que Gynerium es una especie compleja y hasta la fecha, no hay un consenso sobre si estos genotipos pertenecen a la misma especie o especies diferentes. Objetivo: Identificar de forma rápida y precisa plantas de caña silvestre utilizando el espaciador transcrito interno ribosomal nuclear (ITS1+ITS2), tres regiones de cloroplasto (matK, rbcL, ycf1) y sus combinaciones. Métodos: Se utilizaron diferentes pruebas para la discriminación: (1) distancias inter e intraespecíficas, (2) Prueba Best Match (BM), Best Close Match (BCM) y método basado en árboles (3) Neighbor Joining (NJ) y (4) Probabilidad de inferencia bayesiana mediante datos moleculares. Resultados: Los resultadosmostraron que los enfoques BM y BCM revelaron una baja tasa de identificación correcta de especies para los loci ITS+matK (33.3 %) e ITS (28.6 %), mostrando similitud entre las secuencias. Estos resultados fueron respaldados por análisis basados en árboles, donde todas las regiones individuales y las diferentes combinaciones de genes tuvieron una tasa de discriminación de cero (0 %). Conclusiones: los genotipos evaluados pertenecen a la misma especie de caña flecha y las diferencias morfológicas existentes pueden estar relacionadas con plasticidad fenotípica.

Abstract Introduction: The fiber of the Gynerium sagittatum Aubl. P. Beauv is raw material for the elaboration of several handcrafts, which are symbols of Colombian cultural identity. In the manufacture process, different genotypes are used according to the fiber quality and the type of craftsmanship, but it is believed that Gynerium is a complex species, and to date, there is no agreement on whether these genotypes belong to the same species or to different species. Objective: The aim of this study was to quickly and accurately identify wild cane plants using the nuclear ribosomal internal transcribed spacer (ITS1+ITS2), three chloroplast regions (matK, rbcL, ycf1), and their combinations. Methods: Different tests were used for discrimination: (1) inter and intraspecific distances, (2) Best Match (BM), Best Close Match (BCM), and tree-based method (3) Neighbor Joining (NJ) and (4) maximum likelihood and bayesian inference in molecular data. Results: The results showed that BM and BCM approaches revealed the low rate of correct species identification for ITS+matK (33.3 %) and ITS (28.6 %) loci, showing similarity among sequences. These results were further supported by tree-based analyses, where all individual regions and the different gene combinations had a zero discrimination rate. Conclusions: all genotypes belong to the same species of wild cane, therefore existing morphological differences can be related to phenotypic plasticity.

Abstract In the province of Misiones (Argentina), the filling of the Yacyretá Reservoir (Argentina-Paraguay) to its final dimensions in 2011 formed new aquatic ecosystem, e.g., Garupá Stream was converted into a subreservoir. Reports have been made in this stream of adult individuals and spawning of the Family Sciaenidae, excellent colonizers of modified environments. The larvae of this family are morphologically similar, particularly among Pachyurus and Plagioscion species, making taxonomic differentiation difficult. In the present work, sciaenidae larvae were characterized molecularly at the cytochrome c oxidase subunit I gene in order to determine which species use this environment for reproduction. Additionally, genetic distances, Barcode Index Number (BIN) and Automatic Barcode Gap Discovery method (ABGD) were estimated and phylogenetic trees were reconstructed. The results indicated the presence of Plagioscion ternetzi and Pachyurus bonariensis larvae, and for the first time in tributaries of the region, Plagioscion squamosissimus. The incorporation of P. bonariensis and P. squamosissimus to the faunistic assemblage of ichthyoplankton in the Garupá Stream supports better characterization of the species richness of this secondary watercourse modified by the Yacyretá Reservoir, and advancement in our understanding of use of this area for reproduction.

The aim of this study was to analyze the structure of ichthyoplankton in two places in the Parana river upstream the Yacyreta dam during three phases in the waterline filling. Data comes from fortnight collections in two stations for active filtering network 100 m3 with 500 microns and fixed with 4% formaldehyde. In the reservoir, 6 orders and 17 species were recognized, while in the sub damp 7 orders and 35 species were recognized. The most abundant species were Bryconamericus stramineus and Plagioscion ternetzi in the sub damp and Lycengraulis grossidens and Prochilodus lineatus in the reservoir. Preflexion stage was the most frequent in both places. Statistical analysis of the differences in terms of richness and abundance showed significant variations just between reproductive cycles, not between levels. Spawning and growth of early ontogenetic stages zones and feeding and growth zones were recognized for different species with high reproductive success in modified environments.

El objetivo de este trabajo fue analizar la estructura del ictioplancton en dos sitios del rio Parana aguas arriba de la represa de Yacyreta durante tres fases del llenado a cota definitiva. Los datos provienen de colectas quincenales en dos estaciones de muestreo, por filtrado activo de 100 m3de agua, con red de 500 micras y fijadas con formol al 4% in situ. En el embalse se identificaron alrededor de 17 especies y 6 ordenes y en el subembalse 35 especies y 7 ordenes Las especies mas abundantes fueron Bryconamericus stramineus y Plagioscion ternetzi en el subembalse y Lycengraulis grossidens y Prochilodus lineatus en el embalse. El estadio de desarrollo preflexion fue el mas frecuente en ambos sitios. El analisis estadistico de las diferencias a nivel de riqueza y abundancia mostro variaciones significativas solamente entre ciclos reproductivos, no asi entre cotas. Se reconocieron zonas de desove y crecimiento de los primeros estadios ontogeneticos y zonas de alimentacion y crecimiento para diversas especies con alto exito reproductivo en ambientes modificados.

The aim of this work was to characterize the cytogenetic features of the croaker Pachyurus bonariensis (Perciformes, Sciaenidae). Specimens were sampled at three points along the Parana River. Chromosome preparations were obtained by means of cellular suspension from renal tissue. For cytogenetic analysis conventional and differential C and NOR bands staining techniques were applied. We studied 19 individuals of both sexes, from which a diploid number of 48 acrocentric chromosomes was determined (NF=48). There is not evidence of chromosomal sex determination system. NOR banding showed nucleolar organizer regions in pericentromeric regions of a single pair of chromosomes and C banding showed several pericentromeric blocks.

En el presente trabajo se llevo a cabo la primer caracterizacion citogenetica de la corvina Pachyurus bonariensis (Perciformes, Sciaenidae) capturada en tres puntos de muestreo sobre el Rio Parana. Las preparaciones cromosomicas se obtuvieron mediante suspension celular, utilizando tejidos renales y fueron analizadas mediante tecnicas de coloracion convencional y diferenciales (Bandeos C y NOR). Se analizaron 19 ejemplares de ambos sexos a partir de los cuales se pudo determinar un numero cromosomico diploide de 48 cromosomas acrocentricos, sin evidencias de sistemas de determinacion cromosomica del sexo. La tecnica de coloracion argentica mostro regiones organizadoras nucleolares en un solo par de cromosomas y el bandeo C bloques heterocromaticos pericentromericos en varios cromosomas del complemento.