This study was carried out to compare the survival and mutation rates and mutation spectrum by gamma-irradiation on rooted and unrooted cuttings of three spray type (‘Lovelydia’, ‘Yellowbabe’, and ‘Haetsal’) and two standard type (‘Vital’ and ‘Aqua’) cultivars in roses. Two groups, rooted and unrooted cuttings were gamma-irradiated at 70Gy for 24 hours. The irradiated rooted and unrooted cuttings were planted in a greenhouse, and survival, mutation rates and mutation spectrum were investigated 30 weeks after planting, respectively. As a result, survival and mutation rates of gamma-ray irradiated plants were 16.4%~50.8% and 0~5.1% for unrooted cuttings, and 39.4%~55.1% and 0.7%~7.4% for rooted cuttings, respectively. In conclusion, both survival and mutation rates were a little higher on rooted cuttings than on unrooted cuttings. However, when only survived plants after gamma-ray irradiation were considered, mutation rates were 0~10% and 1.8%~14.1% for unrooted cuttings and rooted cuttings, respectively, showing no significant difference. In addition, diverse variations on color and number of petals or shape of flowers were detected both in plants from rooted and unrooted cuttings, which indicated that there was no significant difference in mutation spectrum between two groups.

A rose cultivar, ‘Summer Red’ was developed at Gyeonggi-Do Agricultural Research and Extension Services (GARES) in 2012. A cross was made between ‘Cardinal’ and ‘Fire Fox’ in 2007 and seedlings were produced in 2008. After the test of specific characters from 2010 to 2012, it was finally selected and named. A standard flower type with large sized flower, it has red color (RHS Color Chart Red Group 44B). The leaf was resistant to powdery mildew. It takes 51 days to flowering and cut flower productivity was 168.4 stems/m² in a year. The length of cut flower was long with 82.4 cm and the fresh weight of cut flower was 44.3 g. It has 12.3 cm in flower diameter, 5.5 cm in flower height, 46.7 in petal numbers per flowers and 11 days in vase life. When it grows under the below 15°C and 1,000 lux conditions the petals edge color became dark red in winter season. This new rose cultivar, ‘Summer Red’ was granted on Korea Seed & Variety Service with No. 4867 in 2014.