Abstract: Crosses were made by Griffindesign,using 6 transgenic Bt cotton varieties as parents,to analyze heterosis of F₁ hybrids and the combining ability from 16 traits. F₁ hybrids showed an appreciable heterosis. 13 of 16 characters measured had mid-parent heterosis, 5 showed high-parent heterosis and 14 expressed competitive heterosis. Path analysis indicated that plant height, single boll weight and lint percentage contributed greatly to the increase of output of the yield components. Combining ability analysis showed that the additive effects were predominant in F₁ traits but non-dditive effects of seed cotton yield,lint yield,number of fruit branches,single boll weight lint percentage,rate of rotten boll fiber strength and fiber length were also very strong. Jimian 616 and Hengmian 4 were high vied parents and Jimian 228 was a good quality parent with high genetic combining ability. 8 excellent combinations were selected from 15 F₁ hybrids,3 of which were high yield P1 × P2,P4 × P5,P1×P4,3 were good quality PS × P6,P2 × P5,P3 × P4 and 2 were high yield and good quality P2 × P6,P3 × P5.

Key words: Transgenic Bt cotton, Heterosis, Combining ability

CLC Number: 

• S562.03