Pollen storage for production of seedless watermelon (Citrullus lanatus) using soft-X-irradiated pollen

For the mass production of seedless watermelons induced by pollination of soft-X-irradiated pollen, it is necessary to prepare a lot of irradiated male flowers or pollen prior to pollination. We investigated the storage methods of male flowers and pollen. The characteristics of seedless watermelon induced by the stored pollen were also investigated. When the male flowers were stored with silica gel (ca. 10 times in weight) in sealed container and kept at 5degreesC, the pollen germination on artificial medium was retained well until 20 days after storage. For the long time storage (beyond I month), the use of ethyl acetate (dehydrated) as organic solvent and -20degreesC condition was suitable. There were no differences in quality between the seedless fruits induced by fresh pollen and long time stored pollen.