Effect of shading and nitrogen fertilization on nitrogen metabolism, essential oil content and antimicrobial activity of Achillea millefolium

The Achillea millefolium L. is a perennial herb with important antibacterial, antifungal, anti-inflammatory, antitumoral, and antioxidant properties. This research aimed to investigate the effect of shading (75%; black net) and nitrogen fertilization (0, 75 and 150 kg urea ha-1) on the nitrogen metabolism, essential oil yield and antimicrobial activity of A.millefolium at vegetative- and reproductive-stage. The evaluated parameters varied depending on the organ and the phenological stage of the plant considered. Overall, our findings indicated that shading decreased nitrogen assimilation. Decreased activities of nitrate reductase and glutamine synthetase were observed on shaded plants during reproductive and vegetative stages, respectively. Nitrate and total amino acid levels increased in shaded plants at the vegetative stage. Regarding nitrogen supply, the improved nitrogen metabolism and essential oil yield values were accompanied by intermediate concentrations of urea (75 kg ha-1). Plants fertilized with 75 kg urea ha-1 produced the highest amino acids concentration (vegetative stage), ammonium concentration (vegetative stage) and essential oil yield (reproductive stage). Shading or nitrogen supply did not influence the microbial activity of A. millefolium essential oil.However, the essential oil of leaves and flowers were highly effective against fungi and bacteria, especially gram-positive bacteria. In conclusion, the current study showed that full light and 75 kg urea ha-1 enhanced the nitrogen metabolism of A. millefolium in both vegetative and reproductive stages.

Effects of Inorganic Mulches on Achillea millefolium L. Sesquiterpene Lactones.

Aims: Sesquiterpene lactones are one of the most important groups of bioactive substances in Achillea millefolium, a perennial herb cultivated because of its medicinal interest. We sought to determine if the use of inorganic mulches for weed control in A. millefolium crops could lead to differences in their sesquiterpene lactones (SLs) content. Study Design: A field experiment using a randomized complete block design with three replications was conducted to determine the effect of black polypropylene, black polyethylene of 100 µm and black polyethylene of 175 µm on A. millefolium SLs content. Place and Duration of Study: Department of Crop Production, University of Santiago de Compostela, between September 2004 and August 2005. Methodology: LC/MS analysis of A. millefolium flower heads grown over the three different inorganic mulches and in control plots was carried out in order to determine SLs. Results: Chromatographic analysis of A. millefolium flower heads grown over polypropylene and in control plots revealed the highest diversity of SLs, whereas those developed over black polyethylene showed the least. Polypropylene mulches were shown to be the most efficient with a 2-3 fold increase of total SLs (P < 0.001). The effects of inorganic mulches on individual SLs were of limited relevance. However, the use of black polyethylene (100 µm) resulted in an increase of 8-desacetylmatricarin (P = 0.005), a SL of biological and pharmacological interest. In contrast, concentrations of three unidentified SLs decreased in yarrow plants grown over black polyethylene. Conclusion: Weed density did not show as a major factor influencing the total amount of SLs but growth parameters such as yarrow dry matter were inversely related.

Micro-morphology of Achillea clypeolata: contribution to the pharmacognostical profile.

Achillea clypeolata Sibth. & Sm. is Balkan endemic species, commonly known as yellow yarrow and traditionally used in Bulgarian folk medicine. The purpose of this study was to establish pharmacognostical profile of A. clypeolata, including macroscopic and microscopic morphological characteristics. The study also aims to propose a method for micromorphological investigation and pharmacognostical identification. As a result were established morphological characters necessary for identification of Achilleae clypeolatae flos and Achilleae clypeolatae herba – morphology of stem leaves (lanceolate in shape, pinnately lobed-margin, acute-apex with lamina), ligule petals (2.7-3 mm), involucre bracts (4.5x2 mm) and achenes (1.5-1.7 mm); micromorphology of lamina (110-130 μm), epidermal cells, stomata, glandular, non-glandular trichomes and 3-colporate, echinate pollen grains (20.5-20.8 μm). This study presents new micromorphological data. The used staining method dyed various tissues; makes visible the outlines of structures, tissues and some inclusions; allows by one procedure to visualize important diagnostic features; unlike many other methods, allowing pollen to be used as a characteristic of herbal substances. The results are useful for quality control methods for medicinal plant materials and contributes to the implementation of good practices for plant identification for the herbal industry, food, nutrient supplements and other plant based products.

Crescimento e produção de pigmentos fotossintéticos em Achillea millefolium L. cultivada sob diferentes níveis de sombreamento e doses de nitrogênio / Growth and production of photosynthetic pigments in Achillea millefolium L. grown under different levels of shading and nitrogen

A espécie Achillea millefolium L., conhecida como mil-folhas, é uma planta herbácea, rizomatosa e perene. Sua importância medicinal deve-se às suas atividades antibacterianas, antiinflamatórias, antitumorais, analgésicas e antioxidantes. O efeito da disponibilidade de luz e do nitrogênio sobre o crescimento e produção dessa espécie é pouco conhecido. O objetivo deste trabalho foi avaliar a resposta de A. millefolium L., cultivada sob diferentes níveis de sombreamento e doses de nitrogênio, quanto ao crescimento e à produção de pigmentos fotossintéticos. As plantas foram cultivadas sob três doses de nitrogênio (0, 75 e 150kg uréia ha-1) e submetidas a dois níveis de sombreamento 0 por cento (luz plena) e 75 por cento (sombrite 75 por cento). Adotou-se o delineamento experimental de blocos casualizados com quatro repetições em um fatorial 3x2 (doses de nitrogênio x níveis de sombreamento). O sombreamento influenciou a maioria dos caracteres avaliados, causando uma redução significativa no acúmulo de massa seca da parte aérea (caule + folha + flor), caule, folhas e flores e aumento nos teores de clorofila a, b, total e carotenóides. Os resultados sugerem que a espécie A. millefolium L. possui adaptação à baixa intensidade luminosa, devido às alterações nas características foliares, relacionadas aos teores de pigmentos fotossintéticos.

Achillea millefolium L., known as yarrow, is an herbaceous, rhizomatous and perennial plant. Its medicinal importance is attributed to antibacterial, anti-inflammatory, antitumoral, analgesical and antioxidant activities. The effect of light availability and nitrogen on growth and production of this species is little known. The objective of this study was to evaluate the growth and production of photosynthetic pigments in A. millefolium L. grown under different levels of shading and nitrogen levels. Plants were cultivated under three nitrogen levels (0, 75 and 150kg urea ha-1) and subjected to two levels of shading 0 percent (full light) and 75 percent (75 percent black). The experimental design was delineated in randomized blocks with four replicates in a factorial 3 x 2 (nitrogen levels x levels of shading). The shading influenced most parameters evaluated, causing a significant reduction in dry mass accumulation of shoot (stem + leave + flower), stem, leaves and flowers and increase in levels of chlorophyll a, b, total and carotenoids. Results suggest that Achillea millefolium L. has adaptated to low light intensity, due to changes in leaf traits related to photosynthetic pigments content.

Efeito de extrato bruto e óleo essencial de Achillea millefolium em desenvolvimento in vitro de Corynespora cassiicola e proteção de pepino à mancha de corinespora / Effect of crude extract and essential oil of Achillea millefolium L. on the in vitro development of Corynespora cassiicola and protection of cucumber against corinespora leaf spot

Medidas de controle de doenças por meio do uso de extratos e óleos essenciais vêm sendo investigadas como alternativa aos fungicidas convencionais. Este trabalho objetivou estudar o efeito antimicrobiano de extratos brutos aquosos e óleo essencial de Achillea millefolium no crescimento micelial (CM), na esporulação e na germinação de conídios de Corynespora cassiicola bem como a atividade de peroxidase em plantas de pepino. Para isto, o extrato bruto aquoso (EBA) (1; 5; 10; 20 e 25%) foi incorporado ao meio de cultura BDA (batata-dextrose-ágar) e o óleo essencial (OE) (20, 40, 60, 100 e 200 mL) foi distribuído sobre a superfície do meio de cultura. Disco de micélio foi repicado para os diferentes meios e o crescimento micelial avaliado, diariamente, por 7 dias. Para os ensaios in vivo, plantas de pepino foram pulverizadas com EBAs nas concentrações 1, 10 e 25%, Saccharomyces cereviseae 20% e água, aos quatro e dois dias antes e concomitantemente à inoculação com C. cassiicola. Foi avaliada a severidade da doença e a atividade da enzima peroxidase. Para EBA, não houve inibição do crescimento micelial, da germinação e da esporulação em todas as concentrações testadas. Entretanto, nos tratamentos com OE, houve inibição de até 63% do crescimento micelial. Na esporulação e germinação, a inibição foi de 100% e 98%, respectivamente, na alíquota de 200 ?L para OE. No controle da doença, o tratamento mais efetivo foi EBA a 25% quando realizado concomitante à inoculação. No intervalo de tempo avaliado, não se constatou atividade da enzima peroxidase.

The control of diseases by using crude extracts (CE) and essential oils (EO) are being investigated as an alternative to conventional fungicides. The objective of this work was to evaluate the antimicrobial effect of aqueous extracts and essential oil of Achillea millefolium on mycelial growth, sporolution and spores germination of Corynespora cassiicola, as well as peroxidase activity in cucumber plants. For this, crude extract (1; 5; 10; 20 and 25%) was incorporated into potato dextrose agar medium (PDA), and essential oil (20, 40, 60, 100 and 200 mL) was distributed over the surface of the PDA. The mycelial growth was measured daily for 7 days. In the in vivo test, cucumber plants were sprayed with crude extracts at concentrations 1; 10 and 25%, and Saccharomyces cereviseae 20% (control), 4 and 2 days before and the same time as inoculation with C. cassiicola. The severity of disease and peroxidase activity were evaluated. For crude extract, neither mycelial growth nor spore germination and sporulation was inhibited at any of the tested concentrations. In the treatments with essential oil there was inhibition up to 63% of the mycelial growth. In the sporulation and spores germination the inhibition was 100% and 98%, respectively, for 200uL of EO. In the control of the disease the mosteffective treatment was the crude extract 25% when carried out at the same time as the inoculation. In the evaluated period, no peroxidase activity was found.

Fungitoxidade in vitro de extratos vegetais sobre Exserohilum turcicum (Pass) Leonard & Suggs / In vitro fungitoxicity of plant extracts on Exserohilum turcicum (Pass) Leonard & Suggs

A helmintosporiose, causada pelo fungo Exserohilum turcicum, é uma das principais doenças do milho-pipoca cultivado no Brasil. Devido às características da cultura, como porte da planta, extensão da área de plantio e rentabilidade econômica, o emprego de resistência genética e controle químico têm sido as principais formas de controle da doença. O emprego de agrotóxicos na agricultura tem levado riscos à saúde humana e freqüentes danos ao meio ambiente. Assim, na busca de métodos alternativos para o controle da helmintosporiose foi avaliado o efeito fungitóxico dos extratos vegetais das plantas Achillea milefollium (mil-folhas), Cymbopogon citratus (capim-limão), Artemisia camphorata (cânfora) e Rosmarinus officinalis (alecrim) no crescimento micelial de E. turcicum, em dois meios de cultura (BDA - batata-dextrose-ágar; e LCH - lactose caseína hidrolisada). Os extratos de alecrim e cânfora foram os que apresentaram maior inibição do crescimento micelial nos dois meios de cultura, enquanto que os extratos de mil-folhas e capim limão estimularam o crescimento micelial em meio LCH.

Helminthosporiose is caused by the fungus Exserohilum turcicum and represents one of the main diseases in popcorn grown in Brazil. Due to its characteristics, such as plant size, planting area extension and economic profitability, the use of genetic resistance and chemical control has constituted the main procedure against such disease. The use of pesticides in agriculture has resulted in risks to the human health and frequent damages to the environment. Thus, the fungitoxic effect of plant extracts of Achillea millefolium (yarrow), Cymbopogon citratus (lemon grass), Artemisia camphorata (camphor) and Rosmarinus officinalis (rosemary) on the mycelial growth of E. turcicum was evaluated by using two culture media (PDA - potato dextrose agar, and LCH - lactose-casein hydrolysate) in order to set alternative methods for controlling helminthosporiose. Rosemary and camphor extracts led to higher mycelial growth inhibition in both culture media, whereas yarrow and lemon grass extracts stimulated mycelial growth in LCH medium.