Abstract:
The present research studies the pollen biology of snowdrop (Galanthus nivalis L.), from the point of view of pollen’s germinating potential and length growth of pollen tubes at two temperatures: 18 °C and 4 °C. The germination was conducted “in vitro” on nutritive mediums containing different concentrations of sucrose (0, 5, 10, 15, 20, 25, 40, 50, 70, 100%). The pollen germination was optimum (more than 90 %) on nutritive mediums containing 15 % and 20 % sucrose, at both studied temperatures, after 24 h. In parallel with germination potential, the adaptation of male gametophytes to the two temperatures was analyzed. The longest pollen tubes were formed on 10–25% sucrose mediums at 18 °C and on 10–15% sucrose mediums at 4 °C, and they were maintained also after 120 h since pollen inoculation. For these concentrations, the pollen tube length was similar at both temperatures. In conclusion, 18 °C is suitable for long tubes formation using a largest range of sucrose concentration than 4 °C. In fact, in most plant species, low temperatures not only inhibit pollen tube growth, but also induce flowers abortion. Present results bring new evidences that the snowdrop’s male gametophyte is genetically settled to have a normal development at low temperatures. The optimal germination rate and pollen tube growth at 4 °C highlight the vernal character of the pollen of G. nivalis.