Articles
THE INFLUENCE OF TEMPERATURE UPON GERMINATION OF SOME PRIMULACEAE
The temperature treatments were: 10, 12, 14, 16, 18, 20, 22, 24, 26 and 28°C. All seeds were kept in the dark during germination.
The optimum range of temperature for germination of Cyclamen depends upon the variety.
The following results were obtained: Seeds of the varieties ‘Rheingaufeuer’ and ‘Leuchtfeuer’ prefer 14 to 18°C, ‘Pastell-Dunkellachs’, ‘Miniatur’ and ‘Rosamunde’ 14 to 22°, and ‘Silber’ 16 to 22°C. Evidently there seem to be varieties with a wide or narrow range of optimum temperature as well as with a preference for relatively high or low temperatures.
All of the Primula species tested germinate well at 18°C. Furthermore differences in the ranges of temperature for germination were observed. Primula xkewensis and P. malacoides need a very narrow range of 18 to 20°C. Seeds of Primula obconica germinate well at 16 to 20°, those of P. praenitens at 18 to 26°, and those of P. vulgaris between 18 and 22°C. Maximum germination capacity also differed depending upon the species: Primula xkewensis 77%, P. malacoides 78%, P. obconica 91%, P. praenitens 87%, and P. vulgaris 66%.