The effect of temperature on seed germination in three common bulbous plants of different habitats in the Central Negev Desert of Israel

Bellevalia desertorum the most thermophilous species, germinated better and faster than the other species in all test temperatures. The least thermophilous, Tulipa systola, germinated very poorly in 20 and 25°C, while the intermediate B. eigii did very poorly in 25°C. Germination rates correlated with the maximum soil temperatures in the top 2 cm layer of the soil, and with the rate of drying of this soil layer in their respective habitats, measured 1 wk after rainfall. High winter temperatures on S-facing slopes, B. desertorum's habitat, and the associated rapid desiccation of the soil crust, may exclude T. systola and B. eigii from this habitat. However, low temperature is not a dominant factor causing the absence of B. desertorum of B. eigii from the coolest habitat, inhabited only by T. systola. -from Authors