Effects of temperature and storage time on different varieties of date pollen

Pollen storage could facilitate the date palm hand pollination through saving time and space. The main concern is maintaining pollen viability, which is greatly cultivar dependent and is influenced by storage condition. In this study, to address this issue, the effects of cultivar, storage temperature, and time on pollen germination were investigated. A factorial experiment was laid out in a completely randomized design with three replicates using four cultivars ‘Kazeroon (7013)’, ‘Lar (7035)’, ‘Darab (7016)’ and ‘Qyr-va Karzin (7021)’, four storage temperatures (RT (20 ± 5), 4, -20 and -80°C) and six storage periods (60, 120, 150, 180, 210 and 375 days). Anova of data showed significant effects of variety, storage temperature, storage time and their interactions on pollen germination. The pollen germination rate increased with decreasing temperature. When pollens were stored for up to 150 days, the germination rates of all varieties initially increased then decreased. Overall, the optimum temperature for preserving pollen grains of tested cultivars is -80°C and the highest pollen grain longevity is related to ‘Qyr-va Karzin (7021)’ after one year.