Effect of culture medium pH and sucrose concentration on In Vitro pollen germination in different cultivars of date palm (Phoenix dactylifera L.)

In vitro germination of pollen grains is applied for determination of pollen viability. This study was carried out to evaluate the effect of different levels of pH (4.7, 5.7, 6.7 and 7.7) and sucrose (0, 6, 10, 14 %) separately on in vitro pollen germination in four cultivars of date palm (Vardi, Red Ghannami, Sabz Parak and Pakotah). The experiment was carried out as a factorial based on completely randomized design with three replications. The results showed that with increase in culture medium pH the pollen germination rate of date palm cultivars was increased from 4.7 to 6.7, however, the germination of pollen was decreased in higher pH (7.7). The lowest and highest pollen germination rates were observed in Red Ghannami (73.6 %) and Sabz Parak (57.3 %) under optimum pH condition (6.7), respectively. The effect of sucrose concentration was significant on pollen germination of cultivars. The highest pollen germination percentage was achieved with 6 % sucrose concentration in all cultivars. However, 10 % and 14 % sucrose resulted in a reduced pollen germination. Pakotah cultivar showed highest pollen germination percentage in medium containing 6 % sucrose.