Short communication. Influence of storage temperature on the viability of sweet cherry pollen

The conditions to store sweet cherry pollen of six cultivars ('Brooks', 'Cristobalina', 'Marvin', 'New Star', 'Ruby' and 'Somerset') for a long period of time were studied. Pollen samples were stored at 4 degrees C or -20 degrees C and were taken at 7, 15, 30, 60, 90, 180, 270, 365 or 540 days of storage for all cultivars (with the exception of 'Somerset' at 30 days). 'Cristobalina' showed the highest pollen germination (over 60%). For the rest of cultivars, maximum pollen germination ranged from 36% to 44%. Pollen viability was completely lost for most cultivars after only 60 days of storage at 4 degrees C. However, percentages of germinated pollen in all cultivars were not different from the control after one year of storage at -20 degrees C, with the exception of 'New Star' and 'Marvin' that showed a reduction in pollen germination. Storage for periods longer than one year at -20 degrees C produced a decrease in pollen viability with the exception of 'Cristobalina' and 'Somerset' pollen that maintained similar viability at all times. Results indicate that pollen viability could be maintained at reasonably high percentages after storage at -20 degrees C during one year for all cultivars studied.