In order to breed the useful mutants in black raspberry, cultivated in Gochang-gun, leaf-petiol explants from shoot-proliferating culture was regenerated after irradiated with 30, 50 and 70 Gy gamma-ray. The LD50 dose of leaf-petiol explants was identified as 30Gy after two months. Morphological characteristics of the variants were observed such as stem variation, existence and nonexistence of spine, spine color, anthocyanin content, width of leaf, thick of leaf compared with donor cultivar. Of the 701 mutants, 14 lines with the useful mutant characters were selected and random amplified polymorphic DNA(RAPD) was carried out to confirm mutation state at the molecular level with 20 primers. There are many bands be revealed only in mutants and disappear in mutants reversely. RAPD analysis revealed a high level of genetic diversity among Control and mutants. Compared to Control, No. 14 mutant showed the highest genetic diversity. Also, the co-dominant SSR markers have allowed the evaluation of heterozygosity. Valuable mutants obtained will be useful for developing new cultivars and studying gene function in molecular level.

This study was carried out to investigate the improvement of soil physical and chemistry in black raspberry sequential field. We had used the subsoil-crusher, oriental herbal, perlite, popped rice hull, burned charcoal of rice hull and peat moss as a soil conditioner. On the whole, the physical and chemistry properties of treated-plots was higher than those of Control field after applying soil conditioners. Before planting, the pH and E.C. range of field was 4.9~5 and 0.5~0.6 ds/m, respectively. After applying soil conditioners, the pH and E.C range of Control field was altered to 4.3 and 2.2ds/m and the pH and E.C range of peat moss-field was 5.2 and 1.3 ds/m. The significant difference(p<0.05) in pH and E.C value was observed between Control-field and peat moss-field. In the size of soil aggregate structure, the aggregate structure weight of Control over 4mm long was 44 g and treatments of perlite, popped rice hull, burned charcoal of rice hull and peat moss was 53 g, 65g, 65g and 72g, respectively. There is a significant difference(p<0.05, 0.001) between Control and treatments. In the results of chlorophyll analysis, all of the treated-plots except for the oriental herbal have a high chlorophyll value (p<0.05, 0.001) compared to the Control. In view of the results so far achieved, there is a great difference on the frequency of dead plant between Control and treatments. The dead plants number of Control, subsoil-crusher, oriental herbal, perlite, popped rice hull, burned charcoal of rice hull and peat moss was 31, 21, 7, 12, 10, 12 and 2, respectively.