Summary of Thesis project: Seed dormancy and germination niches of Mediterranean species along an altitudinal gradient in Sardinia
UNIVERSITY OF CAGLIARI
DOTTORATO DI RICERCA IN BOTANICA AMBIENTALE E APPLICATA (XXVII CICLO)
Coordinator: Prof. Gianluigi Bacchetta
SUMMARY OF THESIS PROJECT
Seed dormancy and germination niches of Mediterranean species along an altitudinal gradient in Sardinia
The objectives of the thesis project are to evaluate the effect of environmental factors on the thermal requirements for seed dormancy loss and germination of Mediterranean species. The study areas are located in Sardinia (Italy) along an altitudinal gradient, from the sea level to the highest mountain region (1834 m a.s.l.). Target species have been chosen among those selected in the framework of the “Ensuring the survival of endangered plants in the Mediterranean” project and priority was given to endemic and rare species. Germination tests were then carried out in order to shed light upon the seed ecophysiology of the selected species. To date 10 taxa have been tested, specifically: Aquilegia barbaricina Arrigoni & E. Nardi, Brassica tournefortii Gouan, Clematis vitalba L., Dianthus morisianus Vals., Nepeta foliosa Moris. Digitalis purpurea L. var gyspergerae (Rouy) Fiori, Helianthemum caput-felis Boiss, Scrophularia ramosissima Loisel., Silene succulenta Forssk. subsp. corsica (DC.) Nyman, Verbascum plantagineum Moris. Seeds were incubated in growth chambers at different temperatures without pre-treatments, both in light and darkness conditions. Different pre-treatments were also carried out, in particular Cold stratification, Warm stratification, Dry After Ripening and the addition of Gibberellic acid (GA3) to the medium. To study and monitor the annual trend of soil temperature, 23 data-loggers were buried along the altitudinal gradient where seed collections were also carried out. Germination tests are still in progress as well as the recording of soil temperatures. Through these data it will be possible to identify cardinal temperatures for germination.
Photo: Rosangela Picciau sowing seeds for her Thesis project. Photo (Marco Porceddu)
Tutor:
Prof. Hugh W. Pritchard
Prof. Gianluigi Bacchetta
Co-Tutor:
Dr. Efisio Mattana
Ph.D.Student:
ROSANGELA PICCIAU