Pollination Rate and Pollen Tube Growth in the Gynoecium of Rosa odorata Sweet var.gigantea

The pollination rate and the pollen tube growth in the gynoecia of Rosa odorata var.gigantean were studied to provide scientific basis for making right protection strategy and fostering new cultivars.The pollination efficiency of pollen grains deposited on stigmas of R.odorata var.gigantea was examined and the pollen tube growth in the gynoecia was observed with fluorescence microscopy.Results showed that the pollination rate could reach 100%,and the number of pollen grains reached(84.20±5.87) per pistil at 120 h after sepal opening;some pollen were deposited on stigma at 48 h after sepal opening,a few of pollen germinated soon after.The pollen tube extended into the middle of style at 72 h and passed through the base of style at 90 h after sepal opening and entered into the ovary.The number of stamens averaged(129±20) and pistil averaged(30±5) per flower,and the florescence lasted 5 to 7 d.It would take about 30~40 h from pollens germinating to pollen tubes entering ovules.