Abstract:Twelve hybrid crosses among 3 cytoplasmic male sterile lines and 4 varieties of flue-cured tobacco popular in China were used to determine the heterosis in the following economic characters: yield, production value, average price, high class tobacco ratio, high and middle class tobacco ratio and tobacco class index. Results were as follows: (1) Heterosis from mid-parent was found in most crosses, and the yield and production value in 100.00％ crosses were significantly different at 0.05 or 0.01 levels, so were the other economic characters in 12.50％-83.33％ crosses; (2) Heterosis over higher-parent for yield and high class tobacco ratio was found in most crosses, and the heterosis of yield was in 75.00％ and high class tobacco ratio in 66.67％ crosses were significant at 0.05 or 0.01 levels, respectively. The others economic characters were in 8.33％-50.00％ of crosses with significance at 0.05 or 0.01 levels respectively. (3) The cross of MsYZ203-6 × Honghuadajinyuan showed significant heterosis over higher-parent in all economic characters expressed above, and cross of MsYZ206-9 × Yunyan87 showed significant heterosis over higher-parent in all economic characters above except average price.
