皖杂40杂交棉产量与品质性状的杂种优势表现及遗传分析

 以生产上大面积推广的陆地棉杂交种皖杂40为基础材料，配制多世代群体，进行多年多点多世代群体联合试验，研究该组合杂种优势的表现及杂种优势形成的遗传基础。皖杂40杂交棉的皮棉产量、籽棉产量、单株铃数、铃重、衣分的平均中亲杂种优势F1代分别是26.1％、23.7%、15.1%、6.6％和2.0%；F2代分别是21.1％、19.2%、13.0%、6.4％和1.5%。皖杂40杂交棉的纤维品质性状杂种优势低。高产杂交棉的杂种二代具有在生产上利用价值的产量杂种优势。通过主基因-多基因遗传体系分离分析和多世代平均数联合尺度测验验证，表明控制皖杂40杂交棉皮棉产量、霜前花产量、铃数和衣分的遗传效应主要是显性效应，控制铃重的遗传效应包括加性效应和显性效应。因此，显性效应是该杂交棉产量性状杂种优势形成的主要遗传基础。棉花产量和品质性状存在主基因遗传效应。

Heterosis Performance and Genetic Analysis of Yield and Fiber Qualities of Wanza40 Hybrid Upland Cotton

Wanza40，a popularized hybrid in upland cotton，was used to study the performance and genetic models of heterosis of yield and fiber quality traits. The performance of yield in P1, P2, BC1, BC2, F1 and F2 populations was tested at four experimental environments，and the performance of yield in P1, F1, P2 and F2∶3 populations was further tested at two sites. Fiber samples of P1, P2, BC1, BC2, F1, F2 and F2∶3 populations were selected for examining fiber quality. The averaged heterosis, measured as departure from mid-parent value, for lint yield, seed cotton yield, boll number, boll size and lint percent in F1 were about 26.1％，23.7％，15.1％，6.6％ and 2.0％, respectively, and in F2 generation were about 21.1％，19.2％，13.0％，6.4％ and 1.5％, respectively. The heterosis for fiber quality was very small. The higher heterosis in F2 generation is very useful for cotton production. The result of genetic analysis, by segregation analysis on the major-polygene mixed inheritance model of quantitative traits from multi-generation and by weighted least square estimates method on the genetic model of additive, dominance and epistasis, indicated that dominance was the main genetic basis of heterosis of lint yield，pre-frost seed cotton yield, boll number, and lint percent. In general, there really existed genetic effects of major gene in yield and fiber quality of upland cotton.