Genetic approaches often lead to the most cost-effective and efficient means to improve crops, especially those grown widely. But for most crops, cotton included, genetic improvement efforts have focused far more on above-ground plant attributes than on root systems. Root system establishment is crucial to cotton seedling success, subsequent development, crop performance and sustainability. As a first step toward genetic enhancement of cotton root systems, significant heritable phenotypic variation must be found or created. The overall objective of this research was to study the effect of substituted chromosomes or chromosome segments from the donor tetraploid species Gossypium barbadense, G. mustelinum, and G. tomentosum on the selected traits of the stem, leaf, and especially root in CS lines. Twenty-seven chromosome substitution (CS) lines, containing different pairs or short segments of chromosomes from G. barbadense (CS-B lines), G. mustelinum (CS-M lines), and G. tomentosum (CS-T lines) and two parents, TM-1, parent quasi-isogenic to the CS lines and G. barbadense 3-79, the donor parent to all CS-B lines, were analyzed. Goals were to determine if CS lines significantly affect any of 17 morphological shoot and root traits. Indeed, significant line-based variation occurred for several root and shoot phenotypes. Comparisons of means and two-way hierarchical cluster analysis revealed several CS lines simultaneously affected multiple shoot and/or root traits, positively or negatively. Pairwise correlations of traits and the cluster analysis showed strong relationships among certain traits. The high correlation among several root traits suggests that easier-to-screen traits might be leveraged strategically to devise breeding-friendly methods for phenotypically evaluating root system morphology. Most importantly, this research identifies CS lines with prospectively novel individual trait effects and others with multi-trait effects that can be further dissected and used to improve our knowledge of cotton root systems, their development, genetic control and genetic improvement.

遗传方法通常是改良作物的最具成本效益和最有效的方法，尤其是那些广泛种植的作物。但对于包括棉花在内的大多数作物，遗传改良工作更多地关注地上植物属性，而不是根系。根系建立对棉花幼苗成功、后续发育、作物性能和可持续性至关重要。作为棉花根系遗传增强的第一步，必须发现或创造显着的可遗传表型变异。这项研究的总体目标是研究来自供体四倍体物种Gossypium barbadense、G. mustelinum和G. tomentosum的置换染色体或染色体片段的影响。CS 系中茎、叶、尤其是根的选定性状。27 个染色体置换 (CS) 系，包含来自G. barbadense（CS-B 系）、G. mustelinum（CS-M 系）和G. tomentosum（CS-T 系）的不同染色体对或短片段，以及两个亲本，TM-1，与 CS 系和G. barbadense准同基因的亲本分析了所有 CS-B 系的供体亲本 3-79。目标是确定 CS 品系是否显着影响 17 个形态的枝条和根性状中的任何一个。事实上，几个根和芽表型发生了显着的基于系的变异。平均值和双向层次聚类分析的比较显示几个 CS 品系同时影响多个芽和/或根性状，正面或负面。性状的成对相关性和聚类分析表明某些性状之间有很强的关系。几个根性状之间的高度相关性表明，可以战略性地利用更容易筛选的性状来设计有利于育种的方法来评估根系形态的表型。最重要的是，