Optimização dos testes de germinação para monitorização das colecções de plantas autóctones conservadas em bancos de sementes

• Author(s): Silva, Carla Antónia Mendes
• Date: 2012
• Persistent ID: http://hdl.handle.net/10400.5/5364
• Origin: Repositório da UTL
• Subject(s): seed bank; germination; seed; ex situ conservation; temperature
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Espírito Santo, Maria Dalila; Clemente, Maria Adelaide dos Santos
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia

With the aim to contribute to the optimization of germination tests to monitor the seed collections of native plants conserved in seed banks, germination percentage, germination rate (T50) and lenght of the germination period (T10-90) were evaluated in 16 species studied on four temperatures 15°C, 20°C, 25ºC and 15º/25 ºC. The species were subject to pre-germination treatments to break dormancy: cold stratification (30 days) at 4°C in Scrophulariaceae and Umbelliferae, mechanical scarification in Malvaceae, and Fabaceae, and thermal scarification (115ºC, 10 min.) in Cistaceae. Seeds were incubated in a photoperiod of 8 hours light/16 hours dark. According to results, the species germinated better for the following pretreatements and temperatures: in Cistaceae (thermal scarification): Tuberaria lignosa at 20°C and Halimium lasianthum to 15º/25ºC; in the Fabaceae (mechanical scarification): Adenocarpus complicatus at 15°C and 20°C, Cytisus villosus at 15°C and Vicia sativa subsp.nigra at 20°C; in Malvaceae (mechanical scarification): Alcea rosea at 20°C, Lavatera arborea and Lavatera cretica at 15°C. Pretreatements did not promote the germination of species of the families Scrophulariaceae and Umbelliferae.