Evaluation of connected clonal growth of Solidago chilensis as an avoidance mechanism in copper-polluted soils.

Plant resistance to metals can be achieved by two strategies, tolerance and avoidance. Although metal tolerance has been broadly studied in terrestrial plants, avoidance has been less considered as a strategy to cope with soil metal pollution. Avoidance may be an effective alternative in herbaceous plants with connected clonal growth in environments having high heterogeneity in soil micro-spatial distribution of available metals and other soil conditions (i.e. organic matter). In this study, we performed a laboratory experiment on clonal growth of Solidago chilensis when exposed to copper-spiked soils (800 mg kg-1) at different depths (0, 2, 5 and 8 cm depth), with (20%) and without addition of organic matter to mimic contrasting microhabitats found at smelter hinterlands (i.e. open bare ground and microhabitats below shrubs). Results showed that plants grown in the 2 cm-depth Cu-spiked soils were able to growth and produce ramets and rhizomes. However, increased Cu uptake of plants determined phytotoxic effects and a reduction in clonal spread in the 5 cm- and 8 cm-depth Cu-spiked soils. Addition of organic matter to the Cu-spiked soil layers allowed clonal spread. Considering that ramet and rhizome production is decreased but not inhibited when copper pollution is restricted to the uppermost soil layer (2 cm depth) and that organic matter eliminated soil copper toxicity allowing normal clonal spread, connected clonal growth may be an effective avoidance mechanism of Solidago chilensis, particularly in environments with high heterogeneity in micro-spatial distribution of metals and organic matter in the soil profile and between microhabitats.

Cadmium induced changes in Solidago chilensis Meyen (Asteraceae) grown on organically fertilized soil with reference to mycorrhizae, metabolism, anatomy and ultrastructure.

Solidago chilensis Meyen (Asteraceae) is a medicinal important plant with few studies on nutrition and metabolism and none information on cadmium phytotoxicity. The objective of this study was to investigate Cd induced responses on the growth and metabolism in S. chilensis and on arbuscular mycorrhiza (AM). The experiment was carried out in a greenhouse, consisting of a 5 × 4 factorial with five doses of manure (0, 3.5, 7, 14 and 21gdm-3) and four doses of cadmium (0, 25, 50 and 75mgdm-3) applied to a Dystrophic Ultisol. After 250 days of plant cultivation, biomass, nutrient content, photosynthetic rate, guaiacol peroxidase activity, mycorrhizal colonization, glomalin content, anatomical and ultrastucture were evaluated. Plants were significantly affected by interaction of manure and Cd doses with anatomical, ultrastructural, physiological and nutritional modifications. Manure applied into Cd contaminated soil significantly improved mycorrhizal colonization and glomalin production. The highest organic manure dose (21gdm-3) alleviated toxicity symptoms of Cd on S. chilensis.

Actividad antioxidante en infusiones, tinturas y aceites esenciales de especies nativas de la Patagonia Argentina / Antioxidant activity in teas, tinctures and essential oils of native species from Patagonia Argentina

Introducción: las plantas aromáticas y medicinales son una fuente potencial de componentes antioxidantes. La Patagonia Argentina presenta un ambiente diverso en especies nativas, las cuales deberían ser estudiadas en mayor profundidad debido a su potencial farmacéutico, así como para contribuir a fomentar su conservación. Objetivos: estudiar la actividad antioxidante de infusiones, tinturas y aceites esenciales de las siguientes especies nativas de la Patagonia Argentina: Acantholippia seriphioides (A. Gray) Moldenke, Adesmia boronioides Hook. f., Buddleja globosa Hope, Fabiana imbricata Ruiz & Pav., Solidago chilensis Meyen. Identificar los componentes volátiles presentes en los aceites esenciales. Métodos: se obtuvieron infusiones y tinturas por la guía de las normas de la Farmacopea Argentina VI edición. Los aceites esenciales se obtuvieron por hidrodestilación con un aparato tipo Clevenger. El análisis de los componentes volátiles se realizó mediante cromatografía de gases-espectrometría de masas. Los ensayos de actividad antioxidante se realizaron por el método del difenil-picrilhidrazilo. Resultados: las especies presentaron el siguiente orden de actividad antioxidante: B. globosa > S. chilensis ≥ F. imbricata ≥ A . seriphioides > A. boronioides. Las infusiones de B. globosa, S. chilensis y A. seriphioides, presentaron una actividad antioxidante similar a Camellia sinensis (L.) Kuntze ("té verde") y superior a Ginkgo biloba (L.) Mant (especies reconocidas por su alto contenido de antioxidantes). La actividad encontrada para el aceite esencial de A. seriphioides se deba a sus contenidos en timol y carvacrol. En cuanto a la actividad de S. chilensis podría adjudicarse a su alto porcentaje de limoneno. Conclusiones: este trabajo es el primero que estudia la actividad antioxidante de plantas medicinales y aromáticas en la región noroeste de la Patagonia Argentina; los resultados obtenidos demuestran que las especies estudiadas de dicha región son una fuente rica en compuestos antioxidantes y de potencial valor como suplemento dietario(AU)

Introduction: medicinal and aromatic plants have potential as sources of antioxidant compounds. There is a great diversity of native species in Patagonia Argentina. It is worthy to study them because of its pharmaceutical potential and to help promote conservation. Objectives: to analyze antioxidant activities of herbal teas, tinctures and essential oils of native species from Patagonia Argentina: Acantholippia seriphioides (A. Gray) Moldenke, Adesmia boronioides Hook. f., Buddleja globosa Hope, Fabiana imbricata Ruiz & Pav., Solidago chilensis Meyen. Identify essential oils compounds. Methods: infusions and tinctures were obtained according to Pharmacopoeia Argentina VIth edition. The essential oils were obtained by hydrodistillation in a Clevenger apparatus. Volatiles compounds were analyzed by gas chromatography-mass spectrometry. Antioxidant activity assays were performed by difenil-picrilhidrazilo method. Results: antioxidant activity order was: B. globosa > S. chilensis ≥ F. imbricata ≥ A. seriphioides > A. boronioides. Infusions of B. globosa, S. chilensis and A. seriphioides presented an antioxidant activity similar to Camellia sinensis (L.) Kuntze ("green tea") and higher than Ginkgo biloba (L.) Mant. The A. seriphioides essential oil activity was probably obeyed to thymol and carvacrol presence. S. chilensis activity could be owing to its high limonene content. Conclusions: this study is the first report about antioxidant activity of medicinal and aromatic plants in the northwest region of Patagonia Argentina. The results showed that analyzed species are a rich source of antioxidant compounds and have potential value as a dietary supplement(AU)