Artificial pollination was completed on more than 20 flowers per plant. The flowers were kept in the paper bags for about two weeks. When the hips (fruits) were ripened, the numbers of hips and seed sets were determined. Seed set per hip was calculated by dividing the total number of pistils into fertile seeds. Pollen fertility of selfed plants was determined by examining the stainability with 2.0% acetocarmine solution of more than 500 pollen grains from several flowers.