靑刈用 수수類 一代雜種의 生育 形質 및 乾物生産에 대한 雜種強勢

This study was conducted to obtain fundamental informations necessary to breed forage sorghum at the field of the Livestock Experiment Station from 1988 to 1991. Heterosis was discussed in crossing groups of sorghum x sweet sorghum, sorghum × sudangrass, and (sorghum × sweet sorghum) × sudangrass. Leaf dry weight and stalk dry weight per plant in sweet sorghum crossing group, stalk dry weight per plant in sorghum × sudangrass crosses and leaf area per plant in three way crosses showed the greatest Heterobeltiosis (H b ). There were significant differences in plant height, stalk diameter and number of tillers per plant between sweet sorghum and sudangrass crosses. H b for total dry matter yield in sweet sorghum and sudangrass crosses were 45.9% and 95.0%, respectively. On the other hand, heterosis for total dry matter yield in three way crosses was smaller than H b . There was no relationship between dry matter yield of parents and heterosis of hybrids in sweetsorghum crosses. However, positive correlations between parental yield and hybrid yields were observed. In sudangrass crosses, there were negative correlations between parental yields and heterosis of hybrids. However, no correlation between parental yields and hybrid yields were observed. In three way crosses, there were no correlations between parental yields and heterosis, and between parental yields and hybrids yields.