转Bt基因杂交棉主要性状优势率分布研究

分析了 73个转 Bt基因抗虫杂交组合 F1主要性状的杂种优势及优势率分布 ,认为 :1杂种一代的霜前皮棉产量、株高、铃重、衣分、霜前花率等性状具有明显的正向优势。 2 5 6%的组合霜前皮棉产量竞争优势 ( CH% )集中在 1 0 .1 %～ 35 %之间 ;子棉总产则以 0 .1～ 2 0 %居多 ;铃重、衣分、子指、霜前花率的 CH%主要分布在 0 .1 %～ 1 5 %之间 ;生育期、2 .5 %跨长为负优势 ,多在 - 5 %～ - 0 .1 %之间。 3与 F1相比 ,除子指、2 .5 %跨长外 ,F2主要性状杂种优势均不同程度下降 ,以子棉总产、霜前皮棉产量、霜前花率、单株铃数降幅较大 ;生育期变化较小 ;铃重、衣分、子指虽比 F1有所下降 ,但仍呈现较强的正向优势

Study on Heterotic Distribution of Main Characters of Transgenic Bt Cotton

The heterosis and genetic expression in 73 hybrids of transgenic Bt cotton were analyzed .The result showed: (1)The heterosis of lint yield before frost,plant height,bollweight,lint percentage and rate of blossom before frost were obvious.(2) The distribution of the useful heterosis per character have a different range.That of lint yield of 56%combinations concentrate in 10.1~35%.The useful heterosis of total yield,boll weight,lint percent index and rate of blossom before frost were 0.1~15%.But that of growth duration and 2.5% span length in the hybrids were inferior with the average of 0.1%~5%.(3) The heterosis of main characters in F 2 hybrids except for 2.5% span length and seed index were reduced compared to that of F 1 hybrids. The total yield, lint yield before frost, bolls per plant have the lowest heterosis , boll weight, lint percent and seed index have the highest heterosis.