Conservação e valorização de Asphodelus bento-rainhae P. Silva e Lavandula luisieri (Rozeira) Rivas-Martinez da Beira Interior

• Author(s): Delgado, Fernanda Maria Grácio
• Date: 2010
• Persistent ID: http://hdl.handle.net/10400.5/2858
• Origin: Repositório da UTL
• Subject(s): Asphodelaceae; antifeedant activity; essential oil; Lamiaceae; germination; morphology
• Document Type: Doctoral thesis
• Language: Portuguese
• Advisor(s): Sousa, Maria Edite Texugo
• Contributor(s): Repositório da Universidade de Lisboa

Description

Doutoramento em Engenharia Agronómica - Instituto Superior de Agronomia

The two underlying strategies for the development of this work, which was mainly carried out in the Beira Interior region, were: plant biodiversity protection and the potential sustainable use of this plant biodiversity. On the one hand, as far as conservation is concerned, an endemic species, Asphodelus bento-rainhae P. Silva, whose distribution is restricted to the north slope of the Gardunha mountain, was studied. This species is considered a priority and critically endangered species. On the other hand, as far as sustainable use is concerned, an endemic species of the southwestern Iberian Peninsula, Lavandula luisieri (Rozeira) Rivas-Martínez, was studied. Several laboratory experiments were carried out in order to study A. bento-rainhae seed germination after breaking dormancy-related to hard seed coat. Some experiments were done with seeds recently harvested, while the other experiments were done with seeds after two years of conservation. The results showed that the mechanical scarification treatment was the most effective in overcoming seed dormancy. The predominantly vegetative propagation of the species in the sites under study (oak woods, chestnut woods and cherry tree orchard) may have influenced the morphological uniformity of the specimens studied. There are significant decreases in the development of both floral organs and fruits in shaded plots, which may indicate a preference of this species for both edges of woods and verges, which are exposed to sunlight. This should be taken into account when defining a future strategy for reforestation in long-term population reinforcement plans. The morphological and genetic characteristics of four L. luisieri populations (Vila Velha de Ródão, Mata, Casal da Fraga and Penamacor) were studied. The population of Vila Velha de Ródão showed the highest variability, possibly both due to the habitat fragmentation observed in this area and limited agriculture use. This suggests that the population of Vila Velha de Ródão is both the oldest and the most adapted one to conservation. L. luisieri chemical composition and its biological activity were also studied in the four populations in 2005 and 2006. The population of Penamacor showed the highest antifeedant action and therefore a field of L. luisieri was planted in Castelo Branco to be studied. The plants of this field were analysed chemically in 2006 and 2007 and this antifeedant activity was tested. In 2009, the composition of their essential oil in the different growth stages was analysed. The essential oil of the Beira Interior region populations has in common the trans-α-necrodyle acetate, which is its main compound. The essential oil of the Castelo Branco population maintained or increased its antifeedant activity. The highest percentage of compounds with antifeedant activity occurred in extractions of inflorescences, in early flowering. Conserving the diaspores for the four populations for two years did not show any significant decrease in germination.