Improvement of Germination of Three Endemic Species of the Sierra Nevada (S. Spain)

摘要

Three shrub species—Genista versicolor, Reseda complicata and Thymus serpylloides subsp. serpylloides—endemic of the Sierra Nevada (Spain) and used in the process of replanting the ski slopes of this zone have been studied with the aim of improving their germinative capacity. This work presents the results from a laboratory experiment conducted at three different temperatures (15, 20 and 25°C), studying the effect on germination percentage and rate after the application of certain plant-growth regulators: Inabarplant IV, Ethrel, benzyladenine, and gibberellic acid 3. From the results, it can be concluded that the three species studied present different optimal germination temperatures: 15°C for G. versicolor, 25°C for R. complicata and 20°C for T serpylloides. With respect to the phytoregulators treatments, both in G. versicolor as well as T serpylloides, the action of the benzyladenine was notable at 10 ppm and 25°C, which prompted an increase of 114 and 49% over their respective controls. In the case of R. complicata seeds, the treatments were generally more effective. Thus, Ethrel at 10 and 100 ppm improved the germination indices by 60 and 76%, respectively, benzyladenine at 10 ppm registered a 60% improvement, and GA_3 at 100 ppm a 60% improvement, in all cases at 25°C, the optimal temperature for seed germination in this species.