This study was carried out in order to determine the effects of boron and cold stress on pollen germination of almond hybrids in vitro culture, two different media including the absence and presence of boron (0 mg/l, and 100 mg/l) in 10% sucrose and 1% agar medium at 24°C in dark conditions. The results showed that different treatments had a significant effect on the germination percentage. The highest pollen germination percentage in H24 and S8 almond hybrids was recorded as 98.35 % and 97%, 34% in vitro culture medium containing 100 ppm boric acid, 10% sucrose +1% agar, whereas these amounts were 87.56% and 89.46% in the basic medium without the presence of boric acid, respectively. In conclusion, in vitro pollen germination of almond was inhibited in the medium culture without boron and in cold stress, while it was increased in the medium with boron. Thus, boron can increase the almond yield. پرونده مقاله