One of the main objectives of soybean breeding programs is the search for genotypes that are both high yielding and tolerant to abiotic stresses. Brazilian Cerrado, the main grain-producing region in the country, is characterised by naturally acidic and low fertility soils that consequently have low base saturation. Therefore, identifying genotypes with good performance for favourable and low base saturation stress conditions is of fundamental importance for crop improvement. The objective of this study was to select F₃ soybean populations for multiple traits under contrasting base saturation conditions. Field experiments were carried out in two crop seasons in randomised block design with three replicates and 10 F₃ populations (P1, P2, P3, P4, P5, P6, P7, P8, P9 and P10). In the first experiment, F₃ populations were evaluated without base saturation correction (V = 30%, low saturation), while in the second experiment, limestone was applied 3 months before the start to raise the base saturation to 60% (recommended saturation). We evaluated physiological, nutritional, agronomic and spectral variables. Multivariate analysis was performed to know the populations’ performance and the interrelationship between variables and populations in the saturation conditions evaluated. The F₃ populations showed differential performance for all traits across the conditions tested, enabling the identification of the best populations for each specific condition and both base saturation environments. Population P2 stood out under both low and recommended base saturation conditions and can be used in F₄ plant selection to obtain superior lines for physiological and agronomic traits and vegetation indices.

中文翻译：

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大豆碱基饱和压力：使用多元统计选择多个性状的种群

大豆育种计划的主要目标之一是寻找高产和耐受非生物胁迫的基因型。巴西塞拉多是该国的主要粮食产区，其特点是天然酸性和低肥力土壤，因此碱基饱和度低。因此，鉴定在有利和低碱饱和胁迫条件下具有良好性能的基因型对于作物改良至关重要。本研究的目的是在不同的碱基饱和条件下选择具有多种性状的 F ₃ 大豆种群。田间试验在两个作物季节以随机区组设计进行，具有三个重复和 10 F ₃种群（P1、P2、P3、P4、P5、P6、P7、P8、P9 和 P10）。在第一个实验中，F ₃种群在没有基础饱和度校正的情况下进行评估（V  = 30%，低饱和度），而在第二个实验中，在开始前 3 个月应用石灰石将基础饱和度提高到 60%（推荐饱和度） . 我们评估了生理、营养、农艺和光谱变量。进行多变量分析以了解在评估的饱和条件下群体的表现以及变量和群体之间的相互关系。F ₃种群在测试条件下的所有性状表现出不同的表现，从而能够确定每种特定条件和两种基本饱和环境的最佳种群。种群 P2 在低饱和度和推荐的基础饱和度条件下均表现出色，可用于 F ₄植物选择以获得生理和农艺性状以及植被指数的优良品系。