A STUDY ON KARYOTYPES OF SOME FLOWERS OF ROSA IN CHINA

The present paper reports chromosome numbers and karyotypes of five species and fourteen varieties of Rosa from China. The results are as follows: the small-flowered forms with 2n=2x=14, but a few are mixoploids; the mediumflowered ones with 2n=3x=21; the big-flowered ones with 2n=4x=28. The karyotypes of most cultivars are made of m and sm and a few with st chromosomes. They fall into three types: 1A, 2A and 1B.