Genetic Effects and Heterosis Analysis for Boll Weight and Lint Percentage of Bt Transgenic Upland Cotton Crossed with Superior Fiber Quality Accessions

To detect the genetic effects and heterosis of boll weight and lint percentage of upland cotton (Gossypium hirsutum L.),seven high-yield cultivars (lines) with transgenic resistance to bollworm and five superior fiber quality accessions and 35 crosses derived from these 12 parent lines via North Carolina II design (NC II design) were utilized.The Additive-Dominance model was employed to dissect the genetic effects and predict the heterosis of the two traits.The results indicated that boll weight was mainly dominant genetic effect with variance ratio of 61.1%,while the lint percentage was predominantly affected by additive component with variance ratio of 57.9%.And significant positive population mean heterosis and population over-parents heterosis,8.8% and 4.9%,respectively,was detected for both boll weight at 1% significant level;while there existed significant positive population mean heterosis and negative population over-parents heterosis,though they were low,only 1.8% and-2.2%,respectively.None-existed narrow heritability for boll weight suggested boll weight should be selected in advanced generation while hybrid breeding procedure and its hybrid vigor could be utilized.Whereas lint percentage should be selected in early generation,because the narrow heritability was high(57.9%) for this trait.