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The commensals on Chilean Decapoda of inland waters are characterized by a marked microendemism. The aim of the present study was to do an exhaustive review on the ectocommensals on Chilean inland-water decapods. The literature revealed the presence of species of Protozoa, viz., eight known only from Parastacus pugnax (Lagenophrys andos, Operculigera insolita, O. parastacis, O. seticola, O. striata, O. taura, Chilenophrys allendei, and Circolagenophrys shiftus), one for both P. pugnax and P. nicoletti (L. anticthos), one for Parastacus pugnax and Samastacus spinifrons (O. asymmetrica), and one reported for Aegla laevis (O. velata). In addition, the presence of flatworms was described, specifically Temnocephala chilensis, associated with A. laevis, P. pugnax, and S. spinifrons, and species of Polychaeta, i.e., Stratiodrilus platensis associated with A. abtao and A. bahamondei, S. aeglaphilus for A. laevis, and S. pugnaxi for P. nicoletti. Biogeographical, ecological and taxonomic implications are discussed.

The distributional patterns of the species of the South American freshwater crayfishes of the family Parastacidae were analysed using panbiogeographical track analyses to identify targeted regions of crayfish biodiversity for understanding biogeographical patterns. Two generalized tracks were identified using the track analysis approach: (1) Uruguay and Brazil (Parastacus brasiliensis, P. brasiliensis promatensis, P. buckupi, P. caeruleodactylus, P. defossus, P. fluviatilis, P. gomesae, P. guapo, P. macanudo, P. pilimanus, P. pilicarpus, P. saffordi, P. tuerkayi, P. varicosus); and (2) Central-southern Chile (P. nicoleti, P. pugnax, Samastacus spinifrons, Virilastacus araucanius, V. jarai, V. retamali and V. rucapihuelensis). These areas were exclusive, with no overlap between them. The results indicate the presence of South American Parastacidae crayfish in Atlantic coastal sub-tropical and Pacific coastal temperate wet climate regions with biogeographic similarities to other South American inland water decapods.

The crayfishes of Chile are endemic species and have been poorly studied with respect to their biology. The available literature is restricted to species descriptions, whereas there is no information about other biological topics such as ectocommensals and parasites, which can affect crayfishes. The aim of the present study was to do a literature review and update the information about ectocommensals and parasites that have been reported from Chilean crayfishes. The literature mentioned the presence of Temnocephala chilensis (Platyhelminthes), Stratiodrilus pugnaxi (Polychaeta) and Protozoa such as species of the genera Operculigera and Lagenophrys as ectocommensals for Parastacus pugnax and Samastacus spinifrons. As an endoparasite, Psorospermium haeckelii was reported, a unicellular eukaryotic organism that was found in P. pugnax ovaria. An additional analysis of collected specimens of P. pugnax and S. spinifrons revealed the presence of T. chilensis, albeit at a low incidence. Ecological, biogeographical and evolutionary topics are discussed considering the case of a marked microendemism of an organism associated with Chilean crayfishes.

The Chilean north Patagonian lakes are characterized by their marked oligotrophic or oligomesotrophic status and low abundance of zooplankton species; many of the lakes with oligomesotrophic status are associated with human intervention due to towns on their shores. The aim of the present study was to determine the relations between spectral properties (LANDSAT OLI), chlorophyll and plankton abundances in two north Patagonian lakes: Villarrica, which has two towns on its shores, and Lake Caburgua, which has native forest on its shores. The results revealed that Lake Villarrica has high reflectance in the near infrared, red and green bands, high concentrations of chlorophyll a, the absence of mixotrophic protozoa, and a high abundance of bacterial and plankton, mainly phytoplankton (Chlophyceae and diatoms) and zooplankton. Lake Caburgua, on the other hand, has low reflectance in the same bands, and low chlorophyll concentrations, low bacterial and zooplankton abundances, with the exception of high mixotrophic ciliates and small phytoplankton, and Volvox colonies. The obtained results agree with limnological observations on both lakes, and observations agrees with similar observations of the spectral properties of glacial north Patagonian lakes and of the zooplankton community, and in this scenario, the use of remote-sensing techniques would be a good tool to predict the plankton community in Patagonian lakes.

Antofagasta Bay is characterized by having a high primary productivity due to the presence of the cold Humboldt Stream. However, due to the current global climate change, also the previously generated biodiversity patterns are changing. The aim of the present study was analysing Antofagasta Bay in order to determine the existence of correlations between optical, i.e., spectral, properties recorded through remote sensing on the one hand, and the presence of dinoflagellates and zooplankton, on the other. The studies were done during two periods, i.e., in February 2019 and February 2020. The results revealed the existence of three main groups of sites: a first group comprising sites sampled in February 2019, with high Band 3 and Band 4 reflectance, high chlorophyl values, and high abundances of Dinophysis and copepods; a second group combining four sites visited in February 2019, with high Gymnodinium and Ceratium, high reflectance in Band 1, Band 2, Band 5, Band 6 and Band 7, and low zooplankton abundance; and finally a third group encompassing all sites sampled in 2020, with high Prorocentrum abundance, and low zooplankton abundance, as well as low reflectance. A similar situation with regard to zooplankton and optical properties was earlier reported for Chilean Patagonian lakes.

The Chilean Patagonian lakes are characterized by their marked oligotrophic or oligomesotrophic status and low zooplankton species abundances, many of these lakes with oligomesotrophic status is associated to human intervention due towns in their shores. The aim of the present study was determine the relations between spectral properties (LANDSAT ETM+), chlorophyll and plankton abundances in two north Patagonian lakes, Villarica, that has two towns in its shore, and Caburgua, that has native forest in its shores as basis of environmental pollution monitoring tools. The results revealed that Villarica lake has high reflectances in near infrared, red and green bands, high chlorophyll (a, b and c) concentrations, and high bacterial and plankton abundances, whereas Caburgua lakes has low reflectance in the same bands, and low chlorophyll concentrations, low bacterial and plankton abundances, with exception to high mixotrophic ciliates. The obtained results agree with limnological observations about both lakes, and the comparison with spectral properties agree with similar observations for glacial north Patagonian lakes about spectral properties and zooplankton community.

Antofagasta Bay is characterized by a high primary productivity due to the presence of the cold Humboldt Stream that is associated with a high diversity in flora and fauna in the benthic and pelagial environments of the Chilean west coast. Nevertheless, due to the global climate changes, the existing biodiversity patterns change as well. The aim of the present study was to analyse Antofagasta Bay for determining the existence of patterns between optical properties of the water, and the phytoplankton and zooplankton. The results show that one site had high chlorophyll concentrations, high reflectance, a high abundance of the dinoflagellate genus Dinophysis, and a high abundance of copepodites, whereas five sites had low chlorophyll concentrations, a low reflectance value, low copepodite abundances, and high abundances of dinoflagellates of the genera Ceratium, Gymnodinium and Prorocentrum. These results are similar to earlier observations for the coastal waters along northern Chile.

The effects of a long-term simulated spring-summer UV-B daily course on some anatomical, physiological, and biochemical features were studied in new and old leaves of blueberry (Vaccinium corymbosum L.) cultivars Legacy, Brigitta, and Bluegold. The results show that under UV-B exposure, leaf thickness increased in Bluegold due to an increased intercellular cavities. By contrast, Brigitta maintained its leaf thickness. The net photosynthetic rate was not significantly affected by the UV-B radiation in any of the cultivars; however, Brigitta presented a better photosystem II performance, since this cultivar had more efficient photochemistry under the UV-B radiation. In addition, Brigitta also maintained enhanced total phenol and total anthocyanin content compared to the other cultivars. In conclusion, Brigitta was more resistant to the UV-B radiation than the other two cultivars.

The knowledge of specific germination requirement is important in plants production using seeds. The majority of the native species need of cultural management, among them those related with appropriate conditions to the germination of their seeds. However, available information to develop this methodology in species of Myrtaceae is still conspicuously lacking, as is the case of Myrceugenia exsucca (pitra). Currently, pitra is the most abundant species in the forested wetlands of the Araucanía Region, thus reports of results that contribute to its propagation are important in the conservation of these ecosystems. The objective of the present work was to evaluate the effect of different pregermination treatments (imbibition, cold stratification and gibberellic acid) on viable seeds of M. exsucca through tests of viability and germination under laboratory conditions. The seeds were treated with five treatments: soak in distilled water for 24 h; soak in 250 mg L–1 gibberellic acid for 12 h; soak in 250 mg L–1 gibberellic acid during 24 h; cold stratification at 5 °C during 15 days. Percentage of germination and index of germination velocity were determined. We found 90 % of viability in our experiments. The results showed that the best results were obtained soaking the seeds in distilled water during 24 h with an average germination percentage of 71 %. This information might be required for the management and conservation of M. exsucca., El conocimiento de los tratamientos pregerminativos específicos resulta de interés en la producción de plantas a través de semillas. La mayoría de las especies nativas necesitan de manejos culturales, entre ellos, los relacionados con las condiciones apropiadas para la germinación de sus semillas. Hasta el momento, especificaciones precisas para el desarrollo de estas metodologías en especies de la familia Myrtaceae son escasas, tal es el caso de Myrceugenia exsucca (pitra), especie más abundante en los humedales boscosos de la región de La Araucanía. Así, informar resultados que contribuyan a su propagación por semillas resulta importante en la conservación de este tipo de ecosistemas. El objetivo de este estudio fue evaluar viabilidad y tratamientos pregerminativos en semillas de M. exsucca a través de ensayos de germinación en condiciones de laboratorio. Las semillas fueron tratadas con cuatro tratamientos: remojo con agua destilada por 24 h; remojo en ácido giberélico, 250 mg L–1 por 12 h; remojo en ácido giberélico, 250 mg L–1 por 24 h y estratificación fría a 5 °C por 15 días. Para cada tratamiento se utilizaron cinco repeticiones de 25 semillas cada uno. Se determinó porcentaje de germinación e índice de velocidad de germinación. Como resultado de la prueba de tetrazolium, se obtuvo 90 % de viabilidad. El remojo en agua destilada por 24 h como tratamiento pregerminativo aumenta el porcentaje de germinación, alcanzando 71 %. Esta información podría ser requerida para el manejo y conservación de M. exsucca.

Adequate in vitro micro-environments are crucial to induce life compatible leaf development. Key morphological and physiological traits are needed to allow ex vitro survival. We study, how in vitro light and ventilation affect physiological performance and survival of ex vitro Castanea sativa plantlets. In vitro treatments consisted of two irradiances of 50 and 150 µmol m−2 s−1 in ventilated vessels (VL50 and VL150, respectively), compared to traditional cultures at 50 µmol m−2 s−1 in non-ventilated vessels (NVL50). After the exposure to each condition a photoinhibitory treatment (PhT) was also applied to study whether the above in vitro conditions exerted photoprotection and facilitated the recovery of C. sativa during sudden ex vitro transfer. During rooting, a decrease in net photosynthesis (Psat), electron transport rate (ETRII) and maximal efficiency of PSII (F v /F m ) were observed. Transpiration rates (E) decreased, concomitantly with a rise in water use efficiency (WUE), mainly in microplants originating from ventilated treatments (V). Throughout this stage, the PhT was lethal for all in vitro treatments. During acclimation, the number and leaf size increased principally in plantlets originating from V treatments. These microplants were also able to recover their ETR and F v /F m . Initially, the PhT produced a drastic drop in Fv/Fm of plantlets in all treatments however they did show a tendency to recover. Transferring plantlets to the greenhouse produced a decrease in the Psat in all treatments; however, over time Psat increased reaching values of 3.2 and 5.3 μmol CO2 m−2 s−1 in microplants originating from VL50 and VL150, respectively. Transpiration rate were similar in all treatments and remained at levels of about 0.9 mmol H2O m−2 s−1; thus, WUE increased significantly, reaching values of almost 3.8 µmol CO2/mmol H2O in microplants originating from VL150. After the PhT, all of the plantlet’s recovery capacity increased concomitantly with their dynamic heat dissipation and their de-epoxidation capacity. Our results suggest that managing in vitro conditions can improve plantlets photosynthetic performance in early stages after ex vitro transfer, playing a key role in the ameliorating the transfer stress.

Un número substancial de publicaciones se relacionan con aspectos de fertilización y nutrición de especies leñosas exóticas, principalmente en Eucalyptus spp. y Pinus spp., siendo escasa la información para especies nativas. Berberidopsis corallina (Berberidopsidaceae) es una especie endémica de Chile en peligro de conservación para la cual no existe antecedentes de fertilización. El objetivo de esta investigación es contribuir con nuevos antecedentes sobre el efecto estimulador de la fertilización con nitrógeno (N), fósforo (P) y potasio (K) en el contenido bioquímico foliar en B. corallina, como información base para su conservación. Un experimento de invernadero en condiciones controladas de temperatura y riego fue conducido para evaluar el efecto de la aplicación de N, P, K sobre el contenido foliar de carbohidratos, proteínas y clorofila en plantas de B. corallina obtenidas por estacas. Los tratamientos correspondieron a la aplicación de fertilizante N, P y K en distintas combinaciones aplicado en dosis de 150 mg L-1 de solución fertilizante, preparada a partir de sales hidrosolubles. Los más interesantes resultados se obtuvieron con la aplicación de solución completa (NPK). La clorofila fue el mejor indicador en este experimento del efecto de la fertilización NPK, con un promedio de 8,1 mg mL-1 comparado con el control con un promedio de 2,8 mg mL-1. En general el porcentaje de carbohidratos y proteínas solubles totales aumenta en 41 y 57%, respectivamente, en comparación al tratamiento control. Es destacable el efecto estimulador de la adición de N en las distintas dosis, favoreciendo la síntesis de carbohidratos y proteínas. El efecto estimulador de la fertilización con N, P y K sobre los parámetros bioquímicos de las hojas de B. corallina fue observado principalmente en el contenido de clorofila a y b, permitiendo que las hojas producidas sean fotosintéticamente competentes, aumentando el contenido de carbohidratos y proteínas solubles totales, lo que podría potenciar el crecimiento en condiciones de campo.

The anatomic and functional leaf characteristics related to photosynthetic performance of Castanea sativa growing in vitro and in nursery were compared. The irradiance saturated photosynthesis in in vitro grown plantlets was significantly lower compared to nursery plants (65 vs. 722 μmol m−2 s−1). The maximum photosynthetic rate (PNmax) was 4.0 and 10.0 μmol(CO2) m−2 s−1 in in vitro microshoots and nursery plant leaves, respectively. Carboxylation efficiency (CE) and electron transport rate (ETR) were three-folds higher in nursery plants than in microshoots. The nonphotochemical quenching (NPQ) was saturated at 80 μmol m−2 s−1 in microshoots suggesting limited photoprotection by thermal dissipation. The microshoots had wide open, spherical stomata and higher stomatal density than nursery plants and they had almost no epicuticular wax. Consequently, the microshoots had high stomatal conductance and high transpiration rate. These anatomic and functional leaf characteristics are likely major causes of the low survival rates of plantlets after ex vitro transfer.

The effects of increased doses of UV-B radiation on anatomical, biochemical and molecular features of leaves of two highbush blueberry (Vaccinium corymbosum L. cv. Brigitta and Bluegold) genotypes were investigated. Plants were grown in a solid substrate and exposed to 0, 0.07, 0.12 and 0.19 Wm(-2) of biologically effective UV-B radiation for up to 72 h. Leaf thickness and the adaxial epidermis thickness fell more than 3-fold in both genotypes at the highest UV-B dose. Moreover, in Bluegold an evident disorganization in the different cell layers was observed at the highest UV-B radiation. A significant decrease in chlorophyll a/b after 6 h in Brigitta under the greater UV-B doses was observed. Anthocyanin and total phenolics were increased, especially at 0.19 Wm(-2), when compared to the control in both genotypes.Chlorogenic acid was the most abundant hydroxycinnamic acid in Brigitta, and was significantly higher (P ≤ 0.05) than in Bluegold leaves. Regarding the expression of phenylpropanoid genes, only the transcription factor VcMYBPA1 showed a significant and sustained induction at higher doses of UV-B radiation in both genotypes compared to the controls. Thus, the reduction of leaf thickness concomitant with a lower lipid peroxidation and rapid enhancement of secondary metabolites, accompanied by a stable induction of the VcMYBPA1 transcription factor suggest a better performance against UV-B radiation of the Brigitta genotype.

The limited development of photoprotective mechanisms, specifically heat dissipation capacity, found in micropropagated plants may be the result of low xanthophyll cycle pigment content and reduced de-epoxidation capacity making them highly susceptible to photodamage. The effects of gradual or sudden increase of light on Castanea sativa in vitro cultured and during their ex vitro transference was evaluated. The results were compared with those determined in nursery-grown plants. In vitro plants responded poorly to gradual increase in irradiance, exhibiting a low electron transport rate (ETR) agreeing with low non-photochemical quenching (NPQ) and a limited de-epoxidation capacity, not synthesizing detectable amounts of zeaxanthin (Z). Regarding a sudden increase in light (photoinhibition treatment, PhT); post-PhT as in vitro as well nursery plants showed a significant decrease in their maximal efficiency of PSII ( F v / F m ), but in vitro the decrease was very drastic (around 0.2) different from that observed in nursery (around 0.69). In vitro , NPQ was mainly determined by the slow relaxing component, NPQ s (80.8%), concomitant with a pronounced decrease of D1 protein post-PhT, and a lack of de-epoxidation capacity. During ex vitro transfer, PhT lead to death of some plants, specifically during root induction. The photoprotective mechanisms were activated over time in ex vitro conditions, indicating that micropropagated Castanea sativa display a potential for light acclimation, adjusting their photosynthetic apparatus to the ambient growth irradiance. Understanding the mechanisms that micropropagated plants deployed and how they face high light intensity events, will allow us to search for strategies to improve performance to possible light fluctuations that normally occur in ex vitro conditions during plant acclimation.

Eucryphia glutinosa es una especie endémica de Chile que actualmente se encuentra con problemas de conservación, siendo catalogada como especie rara. Su área de distribución y su contingente poblacional han disminuido considerablemente, por lo que aplicar protocolos de propagación resulta necesario para aumentar el número de individuos. Actualmente existe escasa información respecto a la reproducción vegetativa de esta especie. En consideración a esto, el objetivo del trabajo fue evaluar su capacidad reproductiva mediante rizogénesis de estacas. Se colectaron estacas en abril de 2007 en la Reserva Nacional Malleco, Región de La Araucanía. Las estacas fueron tratadas con ácido indolbutírico (AIB) durante 15 minutos en distintas concentraciones (0, 250, 500, 1.000 y 1.500 mg L-1). Después de mantener las estacas durante siete meses en cama caliente de arraigamiento, se evaluaron los porcentajes de sobrevivencia, de formación de callo y de enraizamiento. Además, se determinó el potencial de crecimiento radical (PCR). Se observó que los mejores resultados se produjeron en la concentración de 500 mg L-1 de AIB, con un 56,5% de enraizamiento.

Berberidopsis corallina es una especie endémica de Chile que debido a su estado de conservación ha sido catalogada como especie “en peligro de extinción”. Su persistente disminución ha estado asociada a tala y competencia con Eucalyptus spp. y Pinus radiata. El objetivo del presente trabajo fue contribuir en la gestión de recuperación de esta especie a través de la evaluación de su capacidad reproductiva mediante propagación por estacas. Para la propagación vegetativa se colectaron estacas semileñosas durante marzo de 2007 en el sector Villa Las Araucarias, Región de La Araucanía. Las estacas cosechadas se trataron con ácido indolbutírico (AIB) en distintas concentraciones (0, 500, 1.000 y 1.500 mg L-1) como factor de enraizamiento. Después de cinco meses de mantenidas las estacas en cama caliente se obtuvo un 87% de enraizamiento total. La concentración de AIB de 1.000 mg L-1 mostró los mejores resultados respecto al proceso de rizogénesis con un 90% de enraizamiento. Además se encontró el mayor promedio de longitud de raíces en este mismo tratamiento con un promedio de 13,64 cm. El mayor número de raíces se obtuvo en el tratamiento 1.500 mg L-1 con un valor promedio de 38,11 raíces por estaca. Se concluye que B. corallina puede ser reproducido vegetativamente a través de la rizogénesis de estacas tratadas con AIB, como una práctica para contribuir a la recuperación de esta especie.

There is variation in rooting capacity among the different species of Nothofagus. Lenga cuttings (N. pumilio) present an almost null answer to rooting, compared to raulí (N. alpina) and roble (N. obliqua). According to antecedents compiled in literature, the endogenous levels of indole acetic acid (IAA), hormone responsible for the formation of adventitious roots, vary depending on the levels of IAA oxidase activity. Based on these observations, the IAA oxidase activity was comparativily analyzed in cuttings from these three Nothofagus species. To quantify the enzymatic activity, a spectrophotometric test was carried out, measuring at 535 nm. The residual amount of IAA was determined by reference to a calibration curve. The enzymatic activity was expressed in IAA mM mg protein–1 hours–1. The results show that lenga presents a greater IAA oxidase enzymatic activity when compared to the other analyzed species (P< 0.05). These results would support at least partially the differences in the rootting capacity in Nothofagus species studys., Entre las distintas especies de Nothofagus existe variación en la capacidad de enraizamiento. Las estacas de lenga (N. pumilio) presentan una respuesta casi nula al enraizamiento, comparada con raulí (N. alpina) y roble (N. obliqua). Según antecedentes recopilados en literatura, los niveles endógenos de ácido indol acético (AIA), hormona responsable de la formación de raíces adventicias, varían según los niveles de actividad de AIA oxidasa (AIA-O). Basados en estas observaciones, la actividad de AIA-O fue comparativamente analizada en estacas de estas tres especies de Nothofagus. Para cuantificar la actividad enzimática se realizó un ensayo de espectrofotometría, midiendo a 535 nm λ. La cantidad residual de AIA se estimó por referencia a una curva de calibración. La actividad enzimática fue expresada en mM de AIA mg de proteína–1 h–1. Los resultados muestran que N. pumilio presenta una mayor actividad enzimática de AIA oxidasa en comparación con las otras especies analizadas (P < 0,05). Estos resultados respaldarían, al menos parcialmente, las diferencias en la capacidad de rizogénesis en las especies de Nothofagus estudiadas.

Para Nothofagus spp. no existe a la fecha información acerca del fraccionamiento y recuperación de proteínas a partir de extracto crudo de estacas, condición necesaria para demostrar in vitro actividad enzimática en presencia de cofactores. Además, esta información es crucial para determinar los niveles de expresión enzimática, lo que permitiría conocer aspectos fisiológicos de las estacas de lenga (Nothofagus pumilio) que podrían estar condicionando la baja respuesta obtenida en los tratamientos de enraizamiento. Para obtener información acerca de lo señalado se validó y estandarizó un protocolo de fraccionamiento, el cual permitió separar proteínas libres de fenoles a partir de extracto crudo de estacas de lenga, como asimismo determinar su contenido. De cada una de las 60 muestras se analizaron 36 fracciones. A partir de la fracción 14 en adelante se obtuvieron proteínas libres de fenoles. Los resultados obtenidos se validaron estadísticamente y mostraron que la técnica permite fraccionar y recuperar proteínas libres de fenoles a través de columna Sephadex G-50 en estacas de lenga (P < 0,05).

Los compuestos fenolicos en concentraciones altas participan como inductores de la oxidacion de auxinas, interfiriendo con la formacion de raices adventicias en estacas de tallo. Al no obtener enraizamiento en estacas de lenga (Nothofagus pumilio (Poepp. et Endl.) Krasser) en invierno y verano, se atribuyo que esto se debia a una alta cantidad de fenoles producidos en lenga, comparado con otros Nothofagus. En este estudio se procedio a cuantificar el contenido de fenoles solubles totales en estacas de lenga a traves del metodo analitico Folin-Dennis, y comparar con el contenido de fenoles solubles totales en rauli (Nothofagus alpina (Poepp. et Endl.) Oerst.), especie que si forma raices adventicias. El contenido de fenoles solubles obtenidos en N. pumilio fue mayor (2254 ± 296 ppm ) que en N. alpina (1978 ± 137 ppm) (P