Effect of different concentrations of medium nutrients on In Vitro pollen germination in date palm (Phoenix dactylifera L.) different cultivars

In vitro pollen germination is an effective technique for understanding the basic and applied aspects of pollen biology. In this experiment, effect of different concentrations of boric acid (0, 50,100, 200 mg l-1), calcium nitrate (0, 100, 200, 300 mg l-1), magnesium sulphate (0, 100, 200, 300 mg l-1) and potassium nitrate (0, 100, 200, 300 mg l-1) were examined on in vitro pollen germination of 4 date cultivars (Ghanami Ghermez, Nar Pakhotah, Sabz Parak and Vardi). The results showed thattype and levels of treatment significantly affected the pollen germination rate in all examined male cultivars.  It was found that pollen germination in all cultivars was decreased by increasing calcium nitrate concentration up to 300 mg l-1 while germination was increased with increase in boric acid and potassium nitrate levels up to 100 mg l-1 and then gradually decreased up to 200 and 300 mg l-1, respectively. The pollen germination was significantly higher at 200 mg l-1 of MgSO4 than other concentrations. Significant differences in germination rate were found among cultivars in different culture media. With optimum concentrations of B, Ca, Mg and K, the highest pollen germination was obtained for Nar Pakotah cultivar