A clone bank that contained highly productive and superior genotypes of R. coreanus Miq. was assembled in 1998. The clone bank was composed of a collection of 227 clones from 15 regions in Korea. From the clone bank, 198 clones that regularly completed flowering and fruiting were used as official materials for superior tree breeding. To evaluate the flowering and fruiting, the length of the fruiting lateral (LF), the number of flowers per fruiting lateral (NFL) and the number of fruit per fruiting lateral (NFFL) were investigated. Fruits were harvested when they fully ripen and the fruit length (FL), fruit width (FW), the weight of fruit (WF) and soluble solids were measured. In 2001, 17 of the original 227 clones were identified as being the most superior, and these selected genotypes were tested for regional adaptability in four different regions in 2002. Finally, these advanced selections including "Jung-Keum 5" were evaluated for flowering, fruiting and fruit production characteristics from 2002 to 2005. The new cultivar, "Jung-Keum 5" has black fruit color and larger fruit size than the contrast clone that was shown mean value for the most characteristics. Selection effect of the new cultivar were shown 148.8% (NFL), 151.2% (NFFL), 125.2% (WF) and 160.4% (yield/individual; YI) superior in comparison with the contrast clone, respectively.

A clone bank that contained highly productive and superior genotypes of R. coreanus Miq. was assembled in 1998. The clone bank was composed of a collection of 227 clones from 15 regions in Korea. From the clone bank, 198 clones that regularly completed flowering and fruiting were used as official materials for superior tree breeding. To evaluate the flowering and fruiting, the length of the fruiting lateral (LF), the number of flowers per fruiting lateral (NFL) and the number of fruit per fruiting lateral (NFFL) were investigated. Fruits were harvested when they fully ripen and the fruit length (FL), fruit width (FW), the weight of fruit (WF) and soluble solids were measured. In 2001, 17 of the original 227 clones were identified as being the most superior, and these selected genotypes were tested for regional adaptability in four different regions in 2002. Finally, these advanced selections including “Jung-Keum 1” were evaluated for flowering, fruiting and fruit production characteristics from 2002 to 2005. The new cultivar, “Jung-Keum 1” has dark red fruit color and larger fruit size than the contrast clone that was shown mean value for the most characteristics. Selection effect of the new cultivar were shown 130.8% (NFL), 128.3% (NFFL), 123.6% (WF) and 173.3% (yield/individual; YI) superior in comparison with the contrast clone, respectively.