RESUMO
This study aims to evaluate the evapotranspiration (EVP) rate of the willow species Salix humboldtiana to be used as a plant species for evapotranspirative willow system (EWS) to treat domestic wastewater in highland climate conditions in Latin America. Twelve lysimeters were installed in Bogotá, Colombia (2,600 m.a.s.l.). Two parameters were evaluated to determine the effect on EVP rate as follows: (a) the plant's age at the plantation time (one year or six months), and (b) the type of water (domestic wastewater or fertilized water). The plant's age was the most important parameter influencing the EVP rate. In addition, the growth of plants was similar (p > 0.05) between individuals irrigated with domestic wastewater and fertilized water. Thus, Salix humboldtiana over one-year-old was recommended to be used in EWS because its EVP rate of 1456 mm y-1, can treat 372 mm y-1 of domestic wastewater under the highland climate conditions. Finally, one EWS planted with Salix humboldtiana to treat domestic wastewater for a Colombian family located in these climate conditions would need an area of 400 m2. This value for area, although similar to other parts of the world, is higher when considering the solar radiation in tropical or sub-tropical climate conditions.
Assuntos
Salix/metabolismo , Purificação da Água/métodos , Biodegradação Ambiental , Clima , Colômbia , Salix/química , Salix/crescimento & desenvolvimento , Águas Residuárias/análise , Purificação da Água/instrumentaçãoRESUMO
This work aimed to study the response of tree willow species to different water soil contents. The experiment was conducted inside a greenhouse using a completely randomized design, in a factorial arrangement of 2 x 3 x 4 with four replicates. Biomass production of Salix x rubens, Salix viminalis and Salix smithiana was higher when the moisture retention capacity of the soil was close to 100%.(AU)
Este trabalho teve como objetivo estudar a resposta de três espécies de vimeiros a diferentes condições hídricas do solo. O experimento foi conduzido em casa de vegetação, com delineamento experimental inteiramente casualizado, disposto em arranjo fatorial de 2 x 3 x 4 com quatro repetições. A produção de biomassa de Salix x rubens, Salix viminalis e Salix smithiana foi maior quando as plantas foram cultivadas em solo com capacidade de retenção de umidade próxima a 100%.(AU)
Assuntos
Salix/crescimento & desenvolvimento , Recursos Hídricos , Condições do SoloRESUMO
This work aimed to study the response of tree willow species to different water soil contents. The experiment was conducted inside a greenhouse using a completely randomized design, in a factorial arrangement of 2 x 3 x 4 with four replicates. Biomass production of Salix x rubens, Salix viminalis and Salix smithiana was higher when the moisture retention capacity of the soil was close to 100%.
Este trabalho teve como objetivo estudar a resposta de três espécies de vimeiros a diferentes condições hídricas do solo. O experimento foi conduzido em casa de vegetação, com delineamento experimental inteiramente casualizado, disposto em arranjo fatorial de 2 x 3 x 4 com quatro repetições. A produção de biomassa de Salix x rubens, Salix viminalis e Salix smithiana foi maior quando as plantas foram cultivadas em solo com capacidade de retenção de umidade próxima a 100%.
Assuntos
Condições do Solo , Recursos Hídricos , Salix/crescimento & desenvolvimentoRESUMO
In willow seeds, photooxidative damage is mainly restricted to the outer cotyledonary tissues, significantly reducing normal germination. Here we analyzed the damage generated in cotyledonary tissues and investigated whether the increase in reactive oxygen species (ROS) generation in seedlings from photooxidized seeds can affect the morphogenetic capacity of the shoot apical meristem. Seeds were photooxidized under different light intensities and the evolution of the damage during seedling growth was studied by light and transmission electron microscopies. The level of lipid peroxidation and changes in antioxidant capacity were measured following the time course of superoxide dismutase, catalase, ascorbate peroxidase and guaiacol peroxidase enzyme activities, and the effect of photooxidative stress on the genesis of new leaf primordia and lateral roots was examined. Early and active endocytosis and autophagy, changes in chloroplast morphology, as well as the accumulation and diffusion of ROS all play important roles in the early cell death observed in cotyledonary tissues. Following germination, seedlings from photooxidized seeds anticipated the emergence of first leaves, which complemented the altered functionality of the damaged cotyledons.
Assuntos
Cotilédone/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Salix/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Análise de Variância , Antioxidantes/metabolismo , Ascorbato Peroxidases/metabolismo , Catalase/metabolismo , Cloroplastos/metabolismo , Cotilédone/metabolismo , Cotilédone/ultraestrutura , Germinação , Luz , Peroxidação de Lipídeos , Malondialdeído/metabolismo , Microscopia Eletrônica de Transmissão , Oxirredução/efeitos da radiação , Peroxidase/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Salix/metabolismo , Plântula/metabolismo , Plântula/ultraestrutura , Sementes/metabolismo , Sementes/efeitos da radiação , Estresse Fisiológico/efeitos da radiação , Superóxido Dismutase/metabolismo , Fatores de TempoRESUMO
Salix nigra seeds subjected to increased humidification show a decrease in normal germination (NG) during early imbibition followed by a recovery in that parameter at increasing imbibition times. Since photo-oxidized seeds contain high levels of reactive oxygen species (ROS), it is possible to infer that the atypical decrease in NG is a consequence of a higher ROS mobilization at early imbibition and the subsequent recovery from an increase in antioxidant activity. In this study, several oxidative stress indicators were evaluated in photo-oxidized seeds subjected to priming. ROS production was studied using electronic spin resonance spectroscopy, spontaneous chemiluminescence (SCL), spectrophotometry (with XTT), and histochemical (with DAB and NBT) and cytochemical (with CeCl(3)) techniques. Four indicators of molecular damage were monitored: lipid peroxidation, pigment destruction, protein oxidation, and membrane integrity. Antioxidant activity was evaluated by changes in the enzymes SOD, CAT, APX, and POX. The results revealed that the decrease in NG at the beginning of priming occurs by an oxidative burst, as determined by increases in both SCL and superoxide anion radical (O2(·-)) Such oxidative burst generates lipid peroxidation, protein oxidation, and a decrease in both pigment content and enzyme activities. With increasing hydration, damages are progressively reversed and NG restored, which coincides with the increased activity of antioxidant defences. It is proposed that these novel observations regarding the occurrence of an oxidative burst are related to the high basal ROS levels and the high membrane content retained in the mature embryo tissues.
Assuntos
Estresse Oxidativo , Salix/metabolismo , Sementes/crescimento & desenvolvimento , Germinação , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Salix/crescimento & desenvolvimento , Sementes/metabolismo , Água/metabolismoRESUMO
The production of reactive oxygen species (ROS) in specific regions of Salix seedlings roots seems essential for the normal growth of this organ. We examined the role of different ROS in the control of root development in Salix nigra seedlings, and explored possible mechanisms involved in the regulation of ROS generation and action. Root growth was not significantly affected by OH quenchers, while it was either partially or completely inhibited in the presence of H2O2 or O2·â» scavengers, respectively. O2·â» production was elevated in the root apex, particularly in the subapical meristem and protodermal zones. Apical O2·â» generation activity was correlated to a high level of either Cu/Zn superoxide dismutase protein as well as carbonylated proteins. While NADPH-oxidase (NOX) was probably the main source of O2·â» generation, the existence of other sources should not be discarded. O2·â» production was also high in root hairs during budding, but it markedly decreased when the hair began to actively elongate. Root hair formation increased in the presence of H2O2 scavengers, and was suppressed when H2O2 or peroxidase inhibitors were supplied. The negative effect of H2O2 was partially counteracted by a MAPKK inhibitor. Possible mechanisms of action of the different ROS in comparison with other plant model systems are discussed.
Assuntos
Raízes de Plantas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Salix/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Western Blotting , Eletroforese em Gel de Poliacrilamida , Peróxido de Hidrogênio/metabolismo , NADPH Oxidases/metabolismo , Peroxidase/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Salix/metabolismo , Plântula/metabolismo , Superóxidos/metabolismoRESUMO
In Argentina, there are numerous native species which are an important source of natural products and which are traditionally used in medicinal applications. Some of these species are going through an intense extraction process in their natural habitat which may affect their genetic diversity. The aim of this study was to establish vegetative propagation systems for three native forestal species of medicinal interest. This will allow the rapid obtainment of plants to preserve the germplasm. This study included the following species which are widely used in folk medicine and its applications: Erythrina crista-galli or "seibo" (astringent, used for its cicatrizant properties and for bronchiolitic problems); Acacia caven or "espinillo" (antirheumatic, digestive, diuretic and with cicatrizant properties) and Salix humboldtiana or "sauce criollo" (antipyretic, sedative, antispasmodic, astringent). The methodology included the micropropagation of seibo, macro and micropropagation of Salix humboldtiana and the somatic embryogenesis of Acacia caven. The protocol for seibo regeneration was adjusted from nodal sections of seedlings which were obtained from seeds germinated in vitro. The macropropagation through rooted cuttings of "sauce criollo" was achieved and complete plants of this same species were obtained through both direct and indirect organogenesis using in vitro cultures. The somatic embryogenesis for Acacia caven was optimized and this led to obtain a high percentage of embryos in different stages of development. We are able to support the conservation of native forest resources of medicinal use by means of vegetative propagation techniques.
Assuntos
Acacia/crescimento & desenvolvimento , Conservação dos Recursos Naturais/métodos , Erythrina/crescimento & desenvolvimento , Plantas Medicinais/crescimento & desenvolvimento , Plantas Medicinais/genética , Salix/crescimento & desenvolvimento , Acacia/genética , Argentina , Erythrina/genética , Variação Genética , Salix/genética , Técnicas de Cultura de Tecidos/métodosRESUMO
Females and males of sexually dimorphic species have distinct resource demands due to differential allocation to reproduction. Sexual allocation theory predicts that functional traits will diverge between sexes to support these demands. However, such dimorphism may be masked by the impact of current reproduction on source-sink interactions between vegetative and reproductive organs. We ask whether natural selection has led to genetic dimorphism in homologous physiological traits between sexes of the dioecious willow shrub, Salix glauca. In a common garden experiment we compared physiological responses to drought stress by male and female ramets in the absence of confounding demands from reproductive structures. Ramets experienced similar pre-dawn leaf water status (Psi(l)) as parental genets in flower within the natural population, indicating that experimental dry-down mirrored environmental conditions in nature. Male and female ramets achieved similar instantaneous water use efficiency, based on the ratio of carbon gain to water loss, under wet and dry conditions. However, female ramets experienced greater water stress (i.e., more negative Psi(l)) than males under dry conditions. Lower Psi(l) for female ramets may partly reflect the maintenance of conductance under drought; males, in contrast, maintain Psi(l) under drought by reducing conductance. Differences between sexes in terms of conductance and leaf water status of the vegetative ramets were absent in a concomitant comparison of parental flowering plants. Our results show (1) genetic divergence in physiology between sexes of S. glauca occurs in the absence of gender-specific reproductive sinks, (2) males are the more physiologically plastic sex with respect to water use, and (3) paradoxically, divergence in water relations between sexes is not detectable at sexual maturity under natural conditions.