Anatomy, seed germination and analysis of essential oil of Viguiera arenaria Baker in Martius and Viguiera robusta Gardner in Hook (Asteraceae - Heliantheae)

Author(s)

Tuane Santos de Oliveira

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2011-12-16

Examining board members

Beatriz Appezzato da Gloria; Fernando Batista da Costa; Marilia Contin Ventrella

• Advisor: Beatriz Appezzato da Gloria

Abstract

Asteraceae family has about 1,600 genera and 20,000 species, representing about 10% of the world flora. In the Cerrado is the second largest family among the phanerogams in number of species with a great importance in the herbaceous and shrubby layers. In the family Asteraceae, Heliantheae is considered a monophyletic group, with 189 genera and approximately 2,500 species of herbs, shrubs and trees. It is a tribe of economical importance, with different uses: food (sunflower), ornamental (dahlia) and medicinal (chamomile). The most important genera of Heliantheae are Bidens, Viguiera and Wedelia. Viguiera Kunth is an exclusively American genus with 180 species, and 27 are exclusively Brazilian. Its representatives occur mainly in Cerrado regions with dry winters and periodic fire events. The adaptation to these environments can be linked to the seasonal behavior of these species, which is the senescence of the aerial organs during periods of low temperatures and dry (dormant phase) and the formation of new aerial organs during periods of water availability and favorable temperatures (flowering phase). Viguiera arenaria Baker in Martius and Viguiera robusta Gardner in Hook are included in Paradosa section in the classification of the genus Viguiera and they are indistinguishable to herborized materials, being distinguished only by their pollen. The anatomical study of V. arenaria and V. robusta aims to contribute to gather of diagnostic characters that aid in the recognition of herborized materials or not. Both species are aromatic in the field, due to the presence of volatile compounds. Phytochemical studies have highlighted the pharmacological potential of these species, based on the activity of terpenes of high molecular weight such as sesquiterpene lactones and diterpenes. The literature lacks, however, data about the chemical composition of the essential oils. This is the reason why their chemical composition is presented in this study. Such information helps, by chemotaxonomy, the distinction among species and besides that, could contribute to identify possible phytotherapics compounds. The study of the seed germination of Viguiera arenaria and V. robusta presented here aims to contribute to the knowledge about the spread of these species towards a possible exploitation of their active compounds, because nowadays they occur only in natural areas of Cerrado. (AU)

• FAPESP's process: 10/02005-1 - Anatomy, germination and comparative analysis of the essential oil of Viguiera arenaria Baker and V. robusta Gardner (Asteraceae-Heliantheae)
• Grantee: Tuane Santos de Oliveira
• Support Opportunities: Scholarships in Brazil - Master