Analysis on the Heterosis and Combining Ability of Major Quantitative Traits in Flue-cured Tobacco

[Objective] To reasonably select hybrid parents and efficiently use the heterosis of tobacco.[Method] 10 flue-cured tobacco varieties were used to make crosses by Griffing Ⅳ design,of which combining abilities of major quantitative traits and heterosis were estimated.[Result] The variances of GCA and SCA of plant height,leaf number,leaf length,internode length and yield were both significantly different at 0.01 level,and the GCA variances of all traits were greater than the SCA variances.Heterosis over higher-parent for yield,production value and average price was found in 50% cross F1.[Conclusion] The genes controlled major quantitative traits in flue-cured tobacco showed additive effect mostly,but non-additive effect appeared obviously in some traits.Heterosis may vary depends on different cross parents,so obtaining higher percentage of hybrids with heterosis over higher-parent in the important economic characters of flue-cured tobacco was absolutely possible.