Study on pollen cryopreservation and pollen germination processes of different cultivars of Osmanthus fragrans

Osmanthus fragrans is very famous flower with rich cultivars in China,but a few seeds were found in nature.The breeding system structures between different cultivars were not studied systematically and the pollen germination obstacles were thought as one important reason.The experiment on different varieties of pollen cryopreservation of osmanthus fragrans showed that the pollen vitality of Osmanthus fragrans was not high,fresh pollen vitality could get setting rate 31.4%.Liquid nitrogen storage could prolong its vitality and vigor remain between 10%and 20%,pollen almost dead after 180d.Study on pollen germination processes found,in natural pollinations,pollen germination started 3dafter flowering;pollen tubes reached ovary about 5~6dafter flowering.After 2hby artificial pollination,pollen germination started on stigma;after 4h,pollen tubes got into stigma;after 24h,pollen tubes reached ovary.And there was a higher pollen germination rate by artificial pollination than by natural pollination.