Browsing by Author "Luzio, Ana"
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- Efeito da aplicação de glicina e betaína na atividade fotossintética da oliveira em regime de sequeiroPublication . Martins, Sandra; Silva, Ermelinda; Gonçalves, Alexandre; Brito, Cátia; Rocha, Luís; Pinto, Luís; Pavia, Ivo; Ferreira, Helena; Dinis, Lia Tânia; Luzio, Ana; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.A oliveira [Olea europaea L.) é uma espécie que frequentemente se encontra sujeita a longos períodos de seca e altas temperaturas, o que afeta a sua atividade fisiológica e, consequentemente, a sua produtividade. A glicina betaína é um importante soluto orgânico que apresenta um papel crucial na tolerância das plantas a alguns tipos de stresse/ incluindo o défice hídrico, por estar envolvido em processos como ajustamento osmótico, destoxificação de espécies reativas de oxigénio e proteção de macromoléculas, sendo também reserva de carbono e fonte de azoto. O objetivo do presente estudo foi investigar os efeitos da aplicação foliar de glicina betaína (25 mM) na atividade fotossintética de oliveiras (cv. Cobrançosa) em plena produção, cultivadas em regime de sequeiro na Terra Quente Transmontana (Suçães, Mirandela). A aplicação do bioestimulante foi efetuada no início do verão e a atividade fisiológica, centrada nas trocas gasosas e no estado hídrico, foi avaliada ao longo dos 3 meses seguintes. A aplicação de glicina betaína conduziu, em julho, a um aumento da taxa de fotossíntese e da eficiência intrínseca do uso da água durante o período da manha, e da condutância estomática durante a tarde. Por outro lado, as plantas tratadas com bioestimulante apresentaram aumento do conteúdo relativo em água no mês de agosto. Os resultados sugerem que a aplicação de glicina betaína provocou um aumento da atividade fisiológica a curto prazo, verificando-se perda de efeito a o longo do tempo. Justifíca-se a necessidade de estudos futuros no sentido de otimizar a concentração e o número de aplicações deste metabolito para obter uma melhor performance da oliveira em condições de sequeiro.
- Fertilização com boro melhora a fisiologia da oliveira em condições de sequeiroPublication . Silva, Ermelinda; Gonçalves, Alexandre; Brito, Cátia; Dinis, Lia Tânia; Rocha, Luís; Luzio, Ana; Pavia, Ivo; Ferreira, Helena; Pinto, Luís; Moutinho-Pereira, José; Ferreira, Isabel Q.; Arrobas, Margarida; Rodrigues, M.A.; Correia, Carlos M.O olival é uma das culturas amplamente distribuídas na região mediterrânica e com grande impacto em Portugal, nomeadamente na região de Trás-os-Montes onde apresenta elevada importância socioeconómica. Sendo a oliveira uma espécie muito exigente em boro e apresentado este micronutriente importantes funções nas plantas, entre as quais na estrutura da parede celular, divisão celular, integridade das membranas, transporte de açúcares e metabolismo dos hidratos de carbono, relações hídricas, floração, frutificaçâo e regulação hormonal, torna-se necessário aprofundar os conhecimentos sobre a resposta da oliveira à fertilizaçâo com boro. O presente estudo foi realizado num olival (cv. Cobrançosa) de sequeiro localizado em Bragança, tendo sido avaliados dois níveis de boro: 3 kg/ha e ausência de boro. Durante o stresse estivai foram avaliados parâmetros de trocas gasosas e fluorescência da clorofila o, conteúdo relativo em água, concentração de pigmentos fotossintéticos e indicadores de crescimento. Verificou-se que as plantas fertilizadas com boro apresentaram maior conteúdo relativo em água, condutância estomática, taxa de transporte de eletrões, quenching fotoquímico e concentração de ciorofilas, conduzindo a incrementos da taxa de fotossíntese líquida e do crescimento, expressa pelo diâmetro do tronco e pelo volume da copa. Estes resultados demonstram que a adição de boro melhora a fisiologia da oliveira em regime de sequeiro, fornecendo nova informação que poderá ajudar a aperfeiçoar as recomendações de fertilizaçâo para a cultura.
- Foliar application of arginine, jasmone, and kaolin ameliorate photosynthesis of olive treesPublication . Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Brito, Cátia; Pinto, Luís; Rocha, Luís; Pavia, Ivo; Luzio, Ana; Dinis, Lia Tânia; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.In Northeast Portugal, olive orchards cover over 75000 ha and involve approximately 36000 producers, being olive oil the only saleable product for many families. Despite the physiological defense strategies that olive trees dispose against summer stress, the projected climate change characterized by severe summer conditions, with low rainfall, excessive heat load and high irradiance leveis might affect this crop. Cropping practices for adaptation of olive orchards to climate change must be pursued. In this work we aimed to investigate the introduction of foliar applications of compounds that have shown a central role in stress tolerance in different plant species. The study was conducted in an organic orchard at Quinta do Prado, Lodões, Vila Flor (41°20'13. 3"N, 7°05'54. 2"W) and shows the impact of the application of arginine (l mM), jasmonate (100 |-iM) and kaolin (5%; w/v) on leaf gás exchange parameters at 6 different times between July and October 2016. Ali compounds, specially kaolin, contributed to the improvement of the photosynthetic activity of olive trees during measurements made during August and September, mainly due to lower stomatal limitations, although a drop of non-stomatal limitations were also recorded at midday period, namely by the end of August. The present study gives new insights about the effect ofthis new cropping practice for olive orchards that can help to mitigate the harsh climatic conditions projected forthe Mediterranean summers.
- Foliar application of melatonin to mitigate olive tree summer stressPublication . Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Brito, Cátia; Pinto, Luís; Rocha, Luís; Pavia, Ivo; Luzio, Ana; Dinis, Lia Tânia; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.Olive crop is widely distributed in the Mediterranean region and has a distinct socioeconomic importance in Portugal, namely in the Northeast region, where mostly rainfed olive orchards cover over 75000 ha and comprise approximately 36000 producers. The projected climate change characterized by severe summer conditions, with low rainfall, excessive heat load and high irradiance levels might affect this crop, notwithstanding the defense strategies that olive trees dispose against summer stress. In this work we aimed to investigate a new cropping practice with the introduction of a foliar application of melatonin (Nacetyl- 5-methoxytryptamine; 100 ~M) that have shown a central role in stress tolerance in different plant species. The study was conducted in an organic orchard of seven-years-old at Quinta do Prado, Lodoes, Vila Flor (41°20'13.3"N, 7"05'54.2"W), Portugal, and shows the impact on leaf gas exchange, chlorophyll a fluorescence, relative water content, concentration of photosynthetic pigments and fruits total phenolic content at 6 different times between July and October 2016. Melatonin sprayed plants consistently showed higher stomatal conductance (18-73% during morning measurements and 11-136% at midday), net photosynthesis (25-81% morning and 32-130% at midday), electron transport rate (12-23% morning and 0.1-13% at midday) and photochemical yield of photosystem 11 (12-24% morning and 0-13% at midday). The better physiological status of the melatonin sprayed olive trees was reflected in a decrease in fruits total phenolic content (21%). The results suggest that the foliar application of melatonin boost the physiological activity of olive trees, giving new insights about the effect of this new cropping practice in olive orchards. Future studies to optimize the concentration and the number of applications of this metabolite must be pursued in order to get a better performance of olive tree under the harsh climatic conditions projected for the Mediterranean region.
- Fruit yield and quality of olives under different deficit irrigation strategiesPublication . Gonçalves, Alexandre; Martins, Sandra; Silva, Ermelinda; Brito, Cátia; Pinto, Luís; Rocha, Luís; Pavia, Ivo; Luzio, Ana; Nunes, Fernando M.; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.The Mediterranean Basin is a climate change hot spot where substantial warming and lower water availability is predicted. This scenario poses considerable challenges to olive groves, a crop with great ecological and socioeconomic importance. ln order to overcome these constrains, new cropping practices focusing on water use efficiency must be investigated. ln this work we aimed to investigate water management practices that can ensure the adequate compromise between yield and the quality of olive products. The study was conducted in Quinta do Prado, Lodões, Vila Flor (41 °20'13.3"N, 7°05'54.2"W) and a full irrigation (FI) control, applied daily, equivalent to 100% of crop evapotranspiration (ETc), was compared with three deficit irrigation strategies (DIS): regulated deficit irrigation (RDI; 80% of ETc in phases I and III of fruit growth and 10% of ETc in pit hardening stage, phase TI; 56 % of the ETc in all season), sustained deficit irrigation (SDI; 27.5% of ETc), and sustained deficit irrigation adopted by the farmer (SDIAF; 21.2% of ETc, applied weekly). The impact of treatments on fruit yield and quality during 2016 were evaluated. Using FI treatment as reference, no significant influence of RDI and SDI treatments were felt in crop yield, while the SDlAF treatment reduced it significantly (P
- Gas Exchange and chlorophyll fluorescence of “Golden Delicious” and “Fugi” apple trees protected by a grey anti-hail coverPublication . Correia, Carlos M.; Silva, Ermelinda; Brito, Cátia; Pinto, Luís; Ferreira, Helena; Luzio, Ana; Dinis, Lia Tânia; Moutinho-Pereira, José; Rodrigues, M.A.; Gonçalves, AlexandreThe frequency and severity of hail events in some apple growing areas of the Iberian Peninsula may increase in the future in the context of climate change. One technological option to minimise potential damages is the use of over-tree netting. Moreover, anti-hail nets can also provide additional benefits by reducing plant stress, sunburn and wind speed. In this work, carried out during 2016, was tested the application of a grey anti-hail net in a commercial orchard with two cultivars (Golden Delicious and Fuji) of apple tree (Malus domestica Borkh.). Although it reduced the photosynthetically active radiation, the grey net had no negative effects on the photosynthetic performance of both apple tree cultivars during the summer season. On contrary, the anti-hail net contributed to the improvement of net photosynthetic rate of “Fuji” plants close to harvest, namely during the afternoon period, reducing the degree of photosynthesis depression from the morning to the afternoon. A strictly association was observed between photosynthesis and stomatal conductance, although non-stomatal limitations to photosynthesis, that include changes in effective photochemical quantum yield of PSII and in electron transport rate, also occur in open sky plants. Therefore, the use of a grey anti-hail net on apple orchards appears as an interesting tool for the protection of apple trees against hail ensuring an adequate photosynthetic activity.
- Gas exchange performance and oxidative stress indicators in olive tree under different deficit irrigation strategiesPublication . Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Brito, Cátia; Pinto, Luís; Rocha, Luís; Pavia, Ivo; Luzio, Ana; Dinis, Lia Tânia; Fernandes-Silva, Anabela; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.The predicted scenario of global warming anticipates severe summer conditions in the Mediterranean basin, with low water availability and excessive heat load. hlence, in arder to overcome the constrains that will affect olive groves and its socioeconomic value, new cropping practices focusing on water use efficiency must be investigated. In this work we aimed to investigate water management practices that can ensure the adequate compromise between yield and the quality of olive products. The study was conducted in Quinta do Prado, Lodões, Vila Flor (41°20'13. 3"N, 7°05'54. 2"W) and different irrigation strategies where investigated: full irrigation (Fl), equivalent to 100% of crop evapotranspiration (ETc), as control treatment, sustained déficit irrigation (SDI; 30% of ETc) and regulated déficit irrigation (RDI; 80% of ETc in phases l and III offruit growth and 10% of ETc in pit hardening stage). The impact of the treatments on leaf gás exchange and oxidative stress indicators during the 2016 summer was evaluated. The results indicate that both déficit irrigation strategies (DIS) allowed to maintain similar values of photosynthetic and transpjration rate and stomatal conductance as in Fl treatment, even in the afternoon period, although occasionally lower values were recorded during summer, namely in RDI plants. Meanwhile, despite the great disparity in the amount of water used among treatments, there were no significant differences in the degree of oxidative stress, judging by the comparative values of photosynthetic pigments, soluble proteins, total thiols and electrolyte leakage. Thus, the DIS used in this study allow an adequate physiological activity of olive trees and give new insights about the effect of these strategies in olive orchards. Since the field trial is located in a commercial farm, production costs, returns, and also fruit quality parameters are being recorded, analysis of which might give an economic insight regarding the sustainability of the implemented techniques.
- Impacto da aplicação foliar de caulino na produção do olival sob rega deficitária e na qualidade da azeitona e do azeitePublication . Gonçalves, Alexandre; Silva, Ermelinda; Martins, Sandra; Brito, Cátia; Pinto, Luís; Rocha, Luís; Pavia, Ivo; Luzio, Ana; Dinis, Lia Tânia; Gomes, Carlos; Nunes, Fernando M.; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.As alterações climáticas projetadas para a bacia do Mediterrâneo, caracterizadas por verões mais severos associados a baixa pluviosidade, carga térmica excessiva e elevados níveis de irradiação poderão afetar a sustentabilidade da olivicultura. Neste estudo, foi investigado a aplicação foliar de caulino, uma prática agrícola inovadora que mostrou anteriormente melhorar a eficiência no uso da água em diferentes espécies vegetais, tendo desta forma um papel central na tolerância ao stresse estivai. O estudo foi realizado na Q.uinta do Prado, Lodões, Vila Flor, em olival em modo de produção biológico sob rega deficitária (27,5% da ETc), tendo sido avaliado o impacto da aplicação de caulino (5%, w/v) no rendimento e qualidade dos frutos e azeite. Com a aplicação foliar de caulino verificou-se um aumento de 54,6 % na produção de azeitona, acompanhada por uma redução do conteúdo total de fenóis e orto-difenóis e da atividade antioxidante (ABTS) e um aumento do conteúdo em flavonoides nos frutos. O tratamento com caulino apresentou teores de gordura mais elevados (60,4% DW) do que o tratamento controlo (48,5% DW). O perfil de ácidos gordos dos frutos não evidenciou alterações significativas entre tratamentos, tendo sido apenas evidente o aumento da concentração de ácido palmitoleico e a diminuição do teor de ácido linoleico nas árvores tratadas com caulino. A extração de azeite, realizada num moinho Oliomio 50 (Mori-Tem, Itália), revelou que o tratamento com caulino apresentou um aumento de 2,3 % no rendimento em azeite e um menor índice de peróxidos. O presente estudo apresenta uma nova visão sobre o efeito desta nova prática agrícola em olival sob rega deficitária, evidenciando que a aplicação foliar de caulino melhora o rendimento, não prejudicando a qualidade do azeite produzido, o que poderá ajudar no desenvolvimento sustentável do sector olivícola.
- Kaolin and salicylic acid alleviate summer stress effects on rainfed olive orchards through distinct physiological and biochemical processesPublication . Brito, Cátia; Dinis, Lia Tânia; Luzio, Ana; Silva, Ermelinda; Gonçalves, Alexandre; Mejón, M.; Escandón, Mónica; Arrobas, Margarida; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.In a changing world, the search for new agronomic practices that help crops to maintain and/or increase yields and quality is a continuous challenge. Olive trees cultivated under rainfed conditions were sprayed with 5% kaolin (KL) and 100 μM salicylic acid (SA) during two consecutive years in the beginning of the summer season. Exogenous KL enhanced relative water content (RWC), stomatal conductance (gs) net photosynthesis (A) and IAA immunodetection, and decreased leaf sclerophylly, secondary metabolites and non-structural carbohydrates accumulation, ABA signal and DNA methylation, contributing to higher growth and yield. The plants treated with SA showed an enhancement in RWC, gs, A, soluble proteins, IAA, ABA and DNA methylation immunodetection and leaf P and Mg concentrations during the summer, leading to higher yield. Thus, KL and SA alleviated some of the negative effects induced by summer stress in olive tree performance, allowing a faster restauration of the physiological functions during the stress relief and leading to higher yields
- Kaolin spray induces changes in ABA and IAA immunodistribution in olive leaves.Publication . Brito, Cátia; Dinis, Lia Tânia; Luzio, Ana; Mejón, M.; Escandón, Mónica; Silva, Ermelinda; Gonçalves, Alexandre; Rodrigues, M.A.; Moutinho-Pereira, José; Correia, Carlos M.The climate change scenarios predicted the accentuation of drought and high temperature events during the summer season in the Mediterranean region, coming up harmful consequences to important crops of this region, such as olive tree (Olea europaea L.). Stress conditions often stimulate changes in plants production, distribution or signal transduction of phytohormones as a response, then modifying their physiology and biochemistry. Kaolin (KL) is a reflecting clay that applied on leaves surface reduce the common damages promoted by heat load and high irradiance levels, being important to test its effect on olive tree hormonal dynamics and physiological parameters. Olive trees of a rainfed orchard in Northeast Portugal, were sprayed with kaolin 5% (KL) and water (C). The immunodistribution of two hormones, abscisic acid (ABA) and indoleacetic acid (IAA), and some physiological and growth responses were accessed. The ABA signal was substantially more pronounced than the IAA signal in all the analyzed leaves, concomitant with the stressful conditions of which these plants were subjected. In general, ABA signal showed a uniform distribution throughout the leaf in both treatments. However, its intensity was higher in C than in KL-sprayed leaves, reflecting the better water status and higher stomatal conductance of the last plants. While in C leaves was observed a uniform distribution of IAA signal trough the leaf limb and an almost absence of signal in the main vascular tissues, in KL-sprayed leaves was observed a higher signal intensity in the main vascular tissues and upper palisade parenchyma. These data suggest its transport and an active growth in KL plants, concomitant with the higher increase of canopy volume. Thus, immunodetection appears to be an efficient tool to understand the translocation of IAA and ABA in plants treated with abiotic stress alleviating products and clarify their role in regulating the physiological responses.