The environmental impact of genetically modified crops has been extensively investigated. However, few reports on the influence of transgenic traits on genetic structure have been reported in the literature. It is unknown how or if transgenic cultivars have affected genotypic variation in upland cotton (Gossypium hirsutum L.) since its rise to dominance in cotton production. In this study, the genotypic variance components, g, of lint yield (LY) and fiber quality were compared among transgenic and nontransgenic cotton in the USDA Regional High Quality (RHQ) tests from 2002 through 2018. The popular transgenic and nontransgenic cultivars/lines developed by the major private and public cotton breeding programs in the United States during this period were included. Testing cycles within the RHQ protocol consist of standardized control cultivars plus experimental entries. Variance components were dissected in each testing year within six such testing cycles. Lint yield of the transgenic cotton was generally higher than nontransgenic cotton. Fiber quality of the nontransgenic cotton was generally higher than the transgenic cotton. For LY, the proportion of g to the total variance was lower in the transgenic cotton than in the nontransgenic cotton, but the difference diminished in the recent two cycles. The proportion of g was lower in the transgenic cotton compared with the nontransgenic cotton for fiber length, fiber strength, fiber uniformity, and micronaire. The discrepancy between the two types of cotton in the RHQ tests reflects the influences of differential breeding schemes in the private and public breeding programs on means and genotypic variance of LY and fiber quality.

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转基因棉花与非转基因棉花的比较研究

转基因作物对环境的影响已得到广泛研究。然而，文献中鲜有关于转基因性状对遗传结构影响的报道。自陆地棉（Gossypium hirsutum L.）在棉花生产中占据主导地位以来，转基因栽培品种如何或是否影响了其基因型变异尚不清楚。在本研究中，基因型方差分量g，在 2002 年至 2018 年美国农业部区域高质量 (RHQ) 测试中，对转基因和非转基因棉花的皮棉产量 (LY) 和纤维质量进行了比较。 主要私人和公共棉花育种计划开发的流行转基因和非转基因品种/品系在此期间的美国被包括在内。RHQ 协议中的测试周期包括标准化的对照品种和实验条目。在六个这样的测试周期内的每个测试年中剖析方差分量。转基因棉花的皮棉产量普遍高于非转基因棉花。非转基因棉花的纤维品质普遍高于转基因棉花。对于 LY，g的比例转基因棉花的总方差低于非转基因棉花，但在最近两个周期中差异缩小。与非转基因棉花相比，转基因棉花中的g比例在纤维长度、纤维强度、纤维均匀度和马克隆值方面较低。RHQ 测试中两种棉花之间的差异反映了私人和公共育种计划中的差异育种计划对 LY 和纤维质量的均值和基因型变异的影响。