Explore the vast range of titles available.

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⁻¹in ventilated vessels (VL₅₀and VL₁₅₀, respectively), compared to traditional cultures at 50 µmol m⁻² s⁻¹in 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/Fₘof 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 CO₂m⁻² s⁻¹in microplants originating from VL₅₀and 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.

Abstract 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.

Abstract 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.

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.

A substantial number of publications are relating to aspects of fertilization and nutrition of woody exotic species, principally in Eucalyptus spp. and Pinus spp., being little the information for native species. Berberidopsis corallina (Berberidopsidaceae) is endemic specie of Chile in danger of conservation for which there is no information about fertilization. The aim of this research is contribute with new antecedent and evaluated the effect stimulatory of nitrogen (N), phosphorus (P) and potassium (K), fertilizer in the biochemical leaf content in B. corallina as information base for his conservation. A greenhouse experiment in controlled conditions of temperature and irrigation was undertaken to evaluate the effect of NPK on the foliar content synthesis of carbohydrates, proteins, chlorophyll in B. corallina plants obtained by cutting. The treatments corresponded to the application of N, P and K in different combinations applied in dose of 150 mg L^sup -1^ of solution fertilizer prepared from hydrosoluble salt. The more interesting results were obtained by the application of complete solution (NPK). The chlorophyll was the best indicator found in this experiment of the effect of NPK fertilization with average of 8.1 mg mL^sup -1^ compared with treatment control with average of 2.8 mg mL^sup -1^. In general the percentage of carbohydrates and soluble total proteins, increased in 41 and 57 % respectively, in compared with treatment control. Notably the stimulatory effect N addition in the different doses stimulated the synthesis of carbohydrates and proteins. The stimulatory effect of fertilization with N, P and K on the biochemical parameters of the leaves of B. corallina was observed fundamentally in the content of chlorophyll a and b, allowing that the leaves produced should be photosynthetically competent, increasing the content of carbohydrates and soluble total proteins, which might promote the growth in field conditions.

The foliar epidermis of the chilean Loranthaceae and its relation with the ecology. The characteristics of the foliar epidermis of the chilean Loranthaceae species are described. Information about their ecology, geographic distribution and a key based on certain features suchs as: size, orientation, disposition and density of stomata are given. The species are charactrized by paracytic stomatal type. Five of the species have anphistomatic leaves: Desmaria mutabilis (P. et E.) Van Tiegh. ex Jacks., Eremolepis punctulata (Clos) Griseb., Ligaria cuneifolia (R. et P.) Van Tiegh., Tristerix tetrandrus (R. et P.) Mart. and T. verticillatus (R. et P.) Barlow et Wiens, and two species have hipostomatic leaves: Lepidoceras kingii Hook. f. and Nothanthera heterophylla (R. et P.) G. Don.