Optimizing culture medium for in vitro germination of date palm (Phoenix dactylifera L.) pollen 1

Medium composition is a major factor affecting in v itro germination of pollen. This experiment was con ducted to determine the best culture medium composition and t ime of pollen germination in two male palm polliniz ers derived from sexual propagation of cultivars, Shahani Jahro m and Zahedi. We tested various combinations of cal cium nitrate (100, 150 and 200 mg L -1 ), potassium nitrate (100 and 150 mg L -1 ) with sucrose (10%), magnesium sulphate (200 mg L -1 ), boric acid (50 mg L -1 ) and agar (1% w/v) on the basis of Brewbaker and K wack's medium. After culture, the pollen cultures are incubated for up t o 30 h at 28 °C. At 12, 18, 24 and 30 h after culture initiation, the number of germinated pollens were recorded. The max imum pollen germination of Zahedi pollinaizer (71.8 2%), was shown in SBMC2K2 medium (10% sucrose, 50 mg L -1 boric acid, 200 mg L -1 magnesium sulfate, 150 mg L -1 calcium nitrate and 150 mg L -1 potassium nitrate) 30 h after incubation. Although this medium was suitable for cv. Shahani Jahrom pollinizer, it showed that the highe st pollen germination in SBMC2K1 medium (10% sucros e, 50 mg L -1 boric acid, 200 mg L -1 magnesium sulfate, 200 mg L -1 calcium nitrate and 150 mg L -1 potassium nitrate). So a variety of media with germination rate higher than 80% could be used for this cultivar. As results we can say that, Shahani Jahrom pollinizer is not so sensitive to ca lcium nitrate and potassium nitrate concentrations. Finally each pollinizer needs special medium for pollen germinat ion.