Identification of chromosome ploidy and analysis of breeding system of different Rosa odorata

Abstract

Abstract [Objective] Rosa odorata is an important germplasm resource of Rosa, which has high value of appreciation and utilization. In order to promote the development and utilization of the germplasm resources, the chromosome ploidy, floral synthesis, and characteristics of breeding systems of different R. odorata were studied. [Methods] The chromosome ploidy, pollen vitality, stigma vitality, and flower characteristics of 9 R. odorata were observed and determined by flow cytometer and outcrossing analysis. We also analyzed the breeding systems. [Results] (1) 9 R. odorata were identified as diploid, and their flowers were bisexual with bright colors and mostly double or semi-double petals. Male and female flowers of 5 varieties were matured at different time. (2) 9 R. odorata pollen vitalities were low, with the highest vitality of 35.47%. The outcrossing index (OCI) of all varieties was ≥4, and pollen volume-ovule ratio (P/O) values ranged from 6 709 to 75 521. [Conclusion] The breeding system of 9 R. odorata is mainly outcrossing, and the breeding system is affected by many factors, such as the number of pollen grains and petals.

Keywords

• rosa odorata
• chromosome ploidy
• floral syndrome
• breeding system