Study on Pollination Biology in Persimmon Trees

There were great differences among different persimmon varieties and species for pollen size and pollen germination.The pollen germination rates for pollination variant of non astringent, Diospyros oleifera and D.lotus were greater than 40%, but lower for pollination constant of non astringent. Boron (5～20 mg/kg) greatly improved pollen germination rate.The storage period of fresh pollen in normal temperature range was from 5～10 days, but 15～20 days in normal temperature and dry condition, and over 30 days in cooler temperature and dry condition.Parthenocarpy capacity was poor for non astringent varieties and some astringent varieties, so pollen supplying trees are necessary to be planted in fruit gardens. Zenjiomaru variety was used as pollen trees which have middle flowering period.But Shougatsu variety has middle or later flowering period. The compatibility among species from persimmen genus was poor, but there were greater differences for fruit setting among varieties, with higher setting rate if Shougatsu was used as male parent tree. 5 superior male parent varieties were suggested.