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Abstract(s)
Hoje em dia, perante a realidade das alterações climáticas, manifestas, por exemplo, nas mudanças nos padrões de precipitação e temperaturas extremas, torna-se necessário encontrar novos métodos de cultivo de plantas medicinais e aromáticas (MAP), uma vez que o clima tem grandes implicações para o metabolismo vegetal. O aproveitamento da água toma particular importância em climas áridos ou semi-áridos como é exemplo o da região Mediterrânica. Uma consequência comum associada à ocorrência de stress hídrico é a diminuição da biomassa que, no contexto do cultivo, resulta numa poupança de água que não compensa a perda de rendimento. No entanto, na última década, a aplicação de fungos micorrízicos arbusculares (AMF) tem sido considerada uma estratégia importante para contrariar os efeitos do stress hídrico, melhorando simultaneamente o rendimento e qualidade das culturas. No presente estudo, uma experiência fatorial baseada no randomized complete block design com três fatores foi realizada para investigar o efeito de AMF e do stress hídrico sobre a composição do óleo essencial (OE), rendimento, características fisiológicas e morfológicas da menta (Mentha sp.) e manjericão (Ocimum basilicum L. cv. Genovese Gigante). Os fatores incluíram a inoculação de um AMF (Glomus intraradices), um nível de irrigação (stress hídrico leve (60% de capacidade de campo)) e a interação de ambos, AMF e stress hídrico. Adicionalmente examinaram-se os efeitos da secagem das plantas e da colheita em duas alturas diferentes (inverno e final da primavera) na produtividade e qualidade dos óleos essenciais.
Inicialmente, as sementes foram germinadas e as plantas transplantadas e transferidas para uma estufa, permitindo melhor controlo das condições do meio. No decorrer da experiência, diferentes características funcionais foram registradas para obter informações relacionadas à influência do AMF e do stress hídrico no desenvolvimento das plantas. Após cada colheita, o rendimento dos óleos essenciais foi registrado e finalmente estes foram analisados com o auxílio de CG e CG-EM.
Em todas as amostras os principais constituintes dos OE para a menta foram o óxido de piperitenona (22%-91%) e para o manjericão o Eugenol (1%-51%) e o Linalool (18%-60%). A maior quantidade de óxido de piperitenona (91%) foi obtida na 1ª colheita com plantas sob stress hídrico e posteriormente secas. Relativamente aos compostos do manjericão, a maior quantidade de Eugenol (51%) foi obtida na 1ª colheita com plantas sob stress hídrico e destiladas em fresco enquanto a maior quantidade de Linalool (60%) foi obtida na 2a colheita com plantas micorrizadas (sem stress hídrico) e posteriormente secas. As condições de stress diminuíram a altura e a biomassa das plantas, enquanto as plantas inoculadas apresentaram uma atenuação dos efeitos adversos do stress hídrico. Como tal, a inoculação micorrízica resultou numa melhoria relativamente aos parâmetros de crescimento, bem como nas características fitoquímicas e fisiológicas da menta e manjericão. Em conclusão, os resultados deste estudo poderam ser úteis para se avaliarem novas possibilidades de melhorar a produtividade, o manejo do cultivo e a qualidade da menta e manjericão em países mais quentes e permitindo um menor input de agroquímicos.
Nowadays, faced with the reality of climate change and increasing threat of unstable precipitation and temperature increase, it is necessary to find new methods of cultivation of medicinal and aromatic plants (MAP), since the climate has great implications for the plant metabolism. The exploitation of water is particularly important in arid or semi-arid climates such as the Mediterranean. A common consequence associated with the occurrence of water stress is the reduction of the biomass that in the context of the crop production, results in the saving of water but does not compensate the loss of profit. However, in the last decade, the application of arbuscular mycorrhizal fungi (AMF) has been considered an important strategy to counteract the effects of water stress while improving crop yield and quality. In the present study, a factorial experiment based on randomized complete block design with three factors was performed to investigate the effect of AMF and water stress on the essential oil (EO) composition, yield, and physiological and morphological characteristics of mint (Mentha sp.) and basil (Ocimum basilicum L. cv. Genovese Gigante). The factors included AMF inoculation (Glomus intraradices), an irrigation level (mild water stress (60% Field capacity)) and the interaction of both AMF and drought stress. In addition, the effects of plant drying and harvesting at two different stages (winter and late spring) on yield and quality of essential oils were examined. Initially, the seeds were germinated, and the plants transplanted and transferred to a greenhouse, allowing a better control of the environment conditions. During the experiment, different functional characteristics were recorded to obtain information related to the influence of AMF and hydric stress on plant development. After each harvest, the yield of the essential oils was registered and finally the latter were analyzed with the aid of GC and GC-MS. The main EO constituents for mint were Piperitenone oxide (22%–91%) and for basil Eugenol (1%-51%) and Linalool (18%-60%). Overall, the highest amount of Piperitenone oxide (91%) was obtained in the 1st harvest with plants under hydric stress and posteriorly dried and the highest amount of Eugenol (51%) was obtained in the 1st harvest with plants under hydric stress, distillated in fresh. In addition, the highest amount of Linalool (60%) was obtained with mycorrhizal plants (without hydric stress) from the 2nd harvest and posteriorly dried. Drought conditions decreased the height and biomass, whereas AMF plants ameliorated the adverse effect of drought conditions. In general, mycorrhizal inoculation resulted in an improvement in the growth parameters as well as the phytochemical and physiological characteristics of mint and basil. In conclusion, the results of this study might be useful to improve the productivity, cultivation management and quality of mint and basil in warmer countries and with less input of agrochemical
Nowadays, faced with the reality of climate change and increasing threat of unstable precipitation and temperature increase, it is necessary to find new methods of cultivation of medicinal and aromatic plants (MAP), since the climate has great implications for the plant metabolism. The exploitation of water is particularly important in arid or semi-arid climates such as the Mediterranean. A common consequence associated with the occurrence of water stress is the reduction of the biomass that in the context of the crop production, results in the saving of water but does not compensate the loss of profit. However, in the last decade, the application of arbuscular mycorrhizal fungi (AMF) has been considered an important strategy to counteract the effects of water stress while improving crop yield and quality. In the present study, a factorial experiment based on randomized complete block design with three factors was performed to investigate the effect of AMF and water stress on the essential oil (EO) composition, yield, and physiological and morphological characteristics of mint (Mentha sp.) and basil (Ocimum basilicum L. cv. Genovese Gigante). The factors included AMF inoculation (Glomus intraradices), an irrigation level (mild water stress (60% Field capacity)) and the interaction of both AMF and drought stress. In addition, the effects of plant drying and harvesting at two different stages (winter and late spring) on yield and quality of essential oils were examined. Initially, the seeds were germinated, and the plants transplanted and transferred to a greenhouse, allowing a better control of the environment conditions. During the experiment, different functional characteristics were recorded to obtain information related to the influence of AMF and hydric stress on plant development. After each harvest, the yield of the essential oils was registered and finally the latter were analyzed with the aid of GC and GC-MS. The main EO constituents for mint were Piperitenone oxide (22%–91%) and for basil Eugenol (1%-51%) and Linalool (18%-60%). Overall, the highest amount of Piperitenone oxide (91%) was obtained in the 1st harvest with plants under hydric stress and posteriorly dried and the highest amount of Eugenol (51%) was obtained in the 1st harvest with plants under hydric stress, distillated in fresh. In addition, the highest amount of Linalool (60%) was obtained with mycorrhizal plants (without hydric stress) from the 2nd harvest and posteriorly dried. Drought conditions decreased the height and biomass, whereas AMF plants ameliorated the adverse effect of drought conditions. In general, mycorrhizal inoculation resulted in an improvement in the growth parameters as well as the phytochemical and physiological characteristics of mint and basil. In conclusion, the results of this study might be useful to improve the productivity, cultivation management and quality of mint and basil in warmer countries and with less input of agrochemical
Description
Keywords
Essential oils from Mint Essential oils from Basil