種間交雜後 戾交雜을 통한 東洋種 호박의 矮性化

Introduction of bushiness from cucurbita pepo to C. moschata through backcross

To breed bush type squash with good flesh quality through interspecific hybridization, two combinations were made between C. pepo (‘Ford Zucchini’) and C. moschata (‘Seoulmadi’ and ‘Puthobag’). Hybrid breakdown was observed in selfed generations. However, fertility tended to recover in the backcrossed generation with C. moschata, from which the generation could be successfully advanced. Several plants with short vine length were selected during the three consecutive selfed generations from BC₁F₁. The estimates of broad sense heritability were higher than. 75 for vine length. Minimum number of genes for vine length was estimated to be 3. In later generations, however, since selection effect was very large in the three consecutive selfed generations from BC₁F₂, it was thought that the character of vine length in interspecific hybrids is mainly governed by 1 or 2 major gene (s). Contents of total solids in fruit were relatively low in C. pepo, high in C. moschata, and intermediate in F₁s between them. The mean content of total solids in the F₂ population was also intermediate, however that of BC₁F₄ population was a little high. Breeding of C. moschata with short vine was thought to be accomplished by the backcross breeding method after interspecific hybridization.