Optimizing Storage and in vitro Germination of Date Palm (Phoenix dactylifera) Pollen

Iran is one of the main date (phoenix dactylifera) producing countries in the world.however, little information is available on the pollen viability and favorable storageconditions of iranian male date cultivars. this study was conducted to estimate the best invitro pollen germination of three male date palm cultivars, `ghanami’, `samsmavi’ and`gheibani’ using various doses of boric acid (0, 50, 100 and 200 mg l-1), calcium nitrate(0, 200 and 300 mg l-1) and sucrose (15% and 25% (w/v)) in a modified brebaker andkwack (mbk) medium. the results showed that the best germination was achieved with50 mg l-1 boric acid, 200 mg l-1 calcium nitrate and 15% (w/v) sucrose. once the optimalin vitro germination medium had been established, pollen viability (% germination) ofthese three cultivars stored for up to 200 days at room temperature (dark and light), in arefrigerator (4°c), freezer (-20°c) and in liquid nitrogen (-196°c) was compared. for allthe tested cultivars, germination declined as storage temperature increased and, by 200days, the highest survival rate was obtained with cryostored pollen. long-term storage ofdate pollen using an ultra-low temperature (-196°c) can be used without anydeteriorating effect on pollen viability, while room temperature storage significantlyreduced pollen germination.