Vantagens e desvantagens da relação entre plantas e fungos

Apresentação efetuada nas III Jornadas Micológicas, Braga, 2011Os fungos são capazes de estabelecer múltiplas associações/relações com as plantas. Apesar de muitas dessas relações se revelarem prejudiciais, outras apresentam vantagens significativas ao nível do desenvolvimento, nutrição e sanidade das plantas. Nesta comunicação será particularmente abordada a associação sirnbiótica que ocorre entre raízes e fungos do solo - micorrização - referindo-se as vantagens que daí advêm para plantas, fungos e inclusivamente para o Homem

Distinguishing allies from enemies-a way for a new green revolution

Plants are continually interacting in different ways and levels with microbes, resulting in direct or indirect effects on plant development and fitness. Many plant-microbe interactions are beneficial and promote plant growth and development, while others have harmful effects and cause plant diseases. Given the permanent and simultaneous contact with beneficial and harmful microbes, plants should avoid being infected by pathogens while promoting mutualistic relationships. The way plants perceive multiple microbes and trigger plant responses suggests a common origin of both types of interaction. Despite the recent advances in this topic, the exploitation of mutualistic relations has still not been fully achieved. The holistic view of different agroecosystem factors, including biotic and abiotic aspects, as well as agricultural practices, must also be considered. This approach could pave the way for a new green revolution that will allow providing food to a growing human population in the context of threat such as that resulting from climate change.This work was supported by FCT (Fundacao para a Ciencia e a Tecnologia) within the framework of CBMA (UIDB/04050/2020) and CIMO (UID/AGR/00690/2020) I&D centers

Reducing Botrytis cinerea incidence in unheated tomato greenhouses in real time using a wireless sensors network.

The objective was to investigate the influence of ventilation on the humidity conditions in unheated tomato greenhouses and the consequences for Botrytis cinerea control and generate the necessary knowledge to build a warning system for this problem. Two different natural ventilation treatments were randomly assigned to the greenhouses. One treatment was permanent ventilation (PV), with the vents open during the day and night, while the other was classical ventilation (CV), in which the vents were open during the day and closed during the night. On a second stage and supported by a wireless network of air relative humidity and temperature sensors a rules based engine with defined setpoints will be developed to make available a early warning system via SMS, e- mail and Web. This will allow the growers to act only when needed, making possible to reduce chemical use, lowering both production costs and environmental impacts

A Greenhouse Tomato Crop Grey Mould Disease Early Warning System

Tomato is a very important crop in the Mediterranean region in general and in Portugal in particular being the production for fresh consumption made essentially in greenhouses. Botrytis cinerea Pers.: Fr. is the causal agent of grey mould disease and is one of the most important diseases affecting greenhouse tomato crops, high relative humidity and the presence of free water on the plant surfaces have been recognized as favourable to the development of this disease. The availability of a early warning system providing to the tomato grower alerts with information of the potential favoured conditions for the disease appearance in its early stages or even before can have a very positive impact in reducing the economic and environmental impacts due to a more rational and efficient disease control management. Today we have the necessary technology to build and launch an Internet based early warning system for grey mould disease in greenhouse tomato crop supported by a wireless sensor network. In this paper a prototype for such a system is presented. From the research conducted until the moment the proposed solution is viable and the next step will be to validate it in the field in different locations and with distinct greenhouses conditions

Evaluation of the biocontrol potential of an antagonist against olive knot disease in olive trees (Olea europaea L.)

The olive knot, caused by the bacterium Pseudomonas savastanoi pv. savastanoi (Psv), is one of the most serious diseases affecting olive tree (Olea europaea L.) in many regions of the world and mainly in Mediterranean countries. This disease produces tumors, especially in olive tree stems and trunk, leading to the death of the plant. In recent years, the use of microbial biocontrol agents for the control of plant diseases has gained considerable attention. Previous studies have revealed that, several bacteria strains naturally occurring in the olive tree phyllosphere, exhibit capacity to inhibit in vitro growth of Psv, being the greatest antagonistic effect displayed by Bacillus En40. The aim of the present study was to evaluate the ability of this strain to suppress Psv and olive knot development in olive trees. Pot experiments were conducted with 2-year-old olive plantlets cv. Cobrançosa inoculated with the selected strain or Psv, or in combination of both. Phenotypic traits associated with plant growth (e.g. biomass yield, total shoot/root height, and photosynthetic pigments content) and biocontrol abilities (e.g. abundance of Psv and assessment of disease symptoms) were evaluated, up to 120 days after inoculation. While development and growth of Psv+antagonist-inoculated plants showed to be similar to non-inoculated plants, photosynthetic pigments contents were observed to be higher in antagonist-inoculated plants than in other treatments. When compared with Psv-inoculated plants, plants treated with the antagonist revealed a significant reduction (p<0.01) in knots formation and size. Antagonist-inoculated plants showed also a reduction of the abundance of Psv in the inoculation sites (from 22.4 to 7.5 UFC/μL, p<0.01), suggesting its capacity to reduce the patogen's growth. This strain was identified to supres Psv and disease development on olive plants and thus, it should be considered in the future as a possible biocontrol agent against olive knot disease.This work is funded by FEDER funds through COMPETE (Programa Operacional Factores de Competitividade) and by national funds by FCT (Fundação para a Ciência e a Tecnologia) in the framework of the project EXCL/AGR-PRO/0591/2012. D. MINA thanks thinfo:eu-repo/semantics/publishedVersio

Patterns of psychotherapy development: A mixed-method analysis using assimilation indices

Understanding how assimilation develops is essential in promoting personal change. By attending to signs or indices of assimilation in the speech of clients, therapists can use this process to assess how the therapy is developing and to tailor intervention. The system of assimilation indices was developed to use assimilation to understand the process of change. This system signals five sub-processes of assimilation: external distress, pain, noticing, decentring, and action. This study consisted of a longitudinal mixed-method analysis, following a multiple cases embedded design. The system of assimilation indices was applied to the recordings of nine psychotherapies and contrasted with both the outcome of the therapy and the perspectives of the therapists and clients about their therapy process. The results show that the system of indices is useful in understanding multiple pathways for assimilation. The system of indices is seen as a useful tool for understanding assimilation and as having clinical value in anticipating challenges to the success of the therapy. This study also shows how the indices are sensitive to the nuances in the change process observed in clinical settings.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

Thermal environment as a management tool in high-rise building

The construction industry is a growing sector in countries that are prosperous in economic development, leading to the new studies that drive this sector. Thus, it appears that the buildings have a great relationship with thermal environment, due to their constant exposure to those factors. This can influence the productivity of workers, compromising the execution of construction. This paper aims at investigating the influence of the thermal environment in building at elevated heights, establishing a relationship with productivity. For that, was done a systematic bibliographic research in more than 30 electronic sites of scientific papers with international scope, seeking to establish the stat of the art starting from the papers published in the last ten years. The definition of portals to search was based on the list included in the Metalib for Exlibris. It appears that there is a relationship between the subjects studied, although most of the survey does not include all the issues, which shows that future works to be performed in this area tend to bring great contribution in the academic community

Avaliação da Poluição Antrópica Usando Padrão de Distribuição deEspécies de Foraminíferos Provenientes de Testemunhos da Baía de Guanabara, RJ.

This work presents a study of benthic foraminifera recovered from three cores collected near the Paquetá island, in the Guanabara bay, Rio de Janeiro, southeastern Brazil. The cores have different sizes and were subsampled in centimetric intervals. The recovered benthic foraminiferal assemblages were thoroughly identified, in order to carry out an ecological study towards reconstructing the environmental evolution of the studied area during the recent historical period and assessing the response of the foraminiferal assemblages to the locally occurring natural and/or anthropogenic impacts. The microfaunal distribution results were correlated with the sedimentological and TOC (Total Organic Carbon) data to understand the environmental trends and evaluate the varying patterns of human-related pollution in the area. 14C isotopic date was taken at the bottom of one core, to help for the local sediment accumulation rates. Species diversity values were low in all samples, whereas the TOC values were commonly high, increasing dramatically upwards across the cores.The dominant species in that area of the Guanabara bay were Ammonia tepida, Elphidium spp. and Buliminella elegantissima. Patterns of the distributions of these species confirm the influence of the anthropogenic pollutiontoward the top of the cores

Efeito de extractos de raízes eliciadas de Castanea sativa no crescimento do fungo ectomicorrízico Pisolithus tinctorius

O castanheiro (Castanea sativa Mill.) estabelece associação com numerosas espécies de fungos ectomicorrízicos, estando descritos os efeitos benéficos para a planta após micorrização com Pisolithus tinctorius. Neste processo é essencial que ocorra a troca de sinais entre os simbiontes, para que seja reconhecida a sua compatibilidade e para que ocorra a formação dos órgãos ectomicorrízicos. Neste trabalho são fornecidas evidências que sugerem a capacidade de extractos de raízes de castanheiro, nos estádios iniciais de contacto com P. tinctorius regularem o crescimento do fungo micorrízico

Competitive interactions between ectomycorrhizal and saprotrophic fungi on chestnut tree

In Northeast of Portugal the macrofungal community associated to chestnut tree (Castanea sativa is rich and diversified. Among fungal species, the ectomycorrhizal Pisolithus tínctorius and the saprotroph Hypholoma fasciculare are common in this habitat. The aim of the present work was to assess the effect of the interaction between both fungi on growth, nutritional status and physiology of C. satíva seedlings. In pot experiments, C. satíva seedlings were inoculated with P. tínctorius and H. fasciculare individually or in combination. Inoculation with P. tinctorius stimulated the plant growth and resulted in increased foliar-N, -P, and photosynthetic pigment contents. These effects were suppressed when H. fasciculare was simultaneously applied with P. tínctorius. This result could be related to the inhibition of ectomycorrhizal fungus root colonization as a result of antagonism or to the competition for nutrient sources. If chestnut seedlings have been previously inoculated with P. tinctorius, the subsequent inoculation of H. fasciculare 30 days later did not affect root colonization and mycorrhization benefits were observed. This work confirms an antagonistic interaction between ectomycorrhizal and saprotrophic fungi with consequences on the ectomycorrhizal host physiology. Although P. tinctorius is effective in promoting growth of host trees by establishing mycorrhizae, in the presence of other fungi it may not always be able to interact with host roots due to an inability to compete with certain fungi.This work has been supported by FCT (PTDC/ AGR-AAM/ 099556/2008)