Low base saturation (V) is one of the major abiotic stresses in the Brazilian Cerrado. Given this scenario, it is important to evaluate different physiological responses of genotypes in environments with and without liming aiming at select both liming responsive and low‐saturation tolerant genotypes. The hypothesis of this study is that contrasting V conditions provide changes in physiological performance of soybean genotypes. Thus, our objective was to select soybean genotypes in environments with recommended and low V. Two field experiments were carried in randomized block design with three replicates and 10 F₃ soybean genotypes (P1, P2, P3, P4, P5, P6, P7, P8, P9 and P10). In the first experiment, genotypes were evaluated without V correction (V = 30%), while in the second experiment, a liming was performed three months before to raise V to 60%. The traits evaluated were as follows: calcium and magnesium contents, days for maturation, transpiration, net photosynthesis, stomatal conductance and internal CO₂ concentration. Our findings indicate that the physiological performance of soybean genotypes depends on the saturation condition. The P9 genotype obtained the best physiological performance under recommended V and can be used to obtain F_3:4 lines physiologically responsive to soil correction. The P5 genotype obtained the best physiological performance at low V and can be used to obtain F_3:4 lines aiming at a higher tolerance to low saturation. Considering that the Brazilian soils, especially in the Cerrado, are mostly poorly fertile, our study provide crucial information for soybean breeding programmes aiming at selecting genotypes tolerant to limiting environmental conditions.

中文翻译：

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大豆基因型对土壤饱和度条件的生理响应和早期性

低碱基饱和度（V）是巴西塞拉多（Cerrado）的主要非生物胁迫之一。在这种情况下，重要的是在有和没有限制的环境中评估基因型的不同生理反应，以同时选择适应性和低饱和度耐性基因型。这项研究的假设是，不同的V条件会改变大豆基因型的生理性能。因此，我们的目标是在推荐的和低V的环境中选择大豆基因型。在随机区组设计中进行了两个田间试验，三个重复试验和10 F ₃大豆基因型（P1，P2，P3，P4，P5，P6，P7，P8，P9和P10）。在第一个实验中，对基因型进行了评估，未进行V校正（V = 30％），而在第二个实验中，在三个月前进行了石灰添加，将V提高至60％。评估的特征如下：钙和镁含量，成熟天数，蒸腾作用，净光合作用，气孔导度和内部CO ₂浓度。我们的发现表明，大豆基因型的生理性能取决于饱和条件。在推荐的V下，P9基因型获得了最佳的生理性能，可用于获得对土壤校正有生理响应的F _3：4品系。P5基因型在低V下获得最佳生理性能，可用于获得F_3：4线旨在对低饱和度具有更高的容忍度。考虑到巴西的土壤，尤其是塞拉多地区的土壤大多贫瘠，我们的研究为大豆育种计划提供了重要信息，旨在选择能够耐受环境条件的基因型。