Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China.
Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China; Centre for AgriBioscience, La Trobe University, Bundoora, VIC 3086, Australia.
Sci Total Environ. 2019 Dec 1;694:133784. doi: 10.1016/j.scitotenv.2019.133784. Epub 2019 Aug 5.
Elevated atmospheric CO concentration (eCO) exerts significant influence on nutrient requirement in plant. The investigation of C:N:P ratios in major cropping soils is important for managing nutrient balance and maximizing their use efficiency in future farming systems. This study aimed to examine the effect of eCO on the C:N:P ratios in different plant parts among soybean cultivars. Twenty-four soybean cultivars were planted in open top chambers at two CO concentrations (390 and 550 ppm) and sampled at the initial pod filling stage (R5) and the full maturity stage (R8). The C, N and P concentrations in root, stem, leaf and seed were determined. Elevated CO decreased the N concentrations in stem (-5.1%) and leaf (-3.2%) at R5, and in root (-24%), stem (-25%) and seed (-6.2%) at R8, resulting in a significant decrease of C:N ratio in the corresponding parts. The P concentration was significantly increased in root (6.0%), stem (7.9%) and leaf (16%) at R5, and in root (2.6%), stem (29%) and seed (16%) at R8 across 24 cultivars, leading to a decrease in the C:P ratio. Elevated CO significantly decreased the N:P ratio in root (-4.5%), stem (-12%) and leaf (-17%) at R5, and in root (-26%), stem (-57%) and seed (-22%) at R8. Furthermore, the response of C:N:P ratios to eCO varied greatly among soybean cultivars leading to significant CO × cultivar interactions. Nitrogen, but not P was the limiting factor for the soybean plants grown in Mollisols under eCO. The considerable variation in the C:N:P ratios among cultivars in response to eCO indicates a potential improvement in soybean adaptability to climate change via selection new cultivars. Cultivars SN22 and ZH4 that did not considerably altered the C:N and C:P ratios in response to eCO are likely the optimal genomes in soybean breeding programs for eCO adaption.
大气中 CO 浓度升高（eCO）对植物的养分需求有显著影响。研究主要作物土壤中的 C:N:P 比值对于管理养分平衡和最大限度提高未来耕作系统中养分利用效率非常重要。本研究旨在探讨 eCO 对不同大豆品种各器官中 C:N:P 比值的影响。在两个 CO 浓度（390 和 550 ppm）的开顶式气室中种植 24 个大豆品种，并在初始豆荚填充期（R5）和完全成熟期（R8）取样。测定根、茎、叶和种子中的 C、N 和 P 浓度。与对照相比，R5 时 eCO 降低了茎（-5.1%）和叶（-3.2%）中的 N 浓度，R8 时降低了根（-24%）、茎（-25%）和种子（-6.2%）中的 N 浓度，导致相应部位的 C:N 比显著降低。与对照相比，R5 时 24 个品种的根（6.0%）、茎（7.9%）和叶（16%）中的 P 浓度显著增加，R8 时根（2.6%）、茎（29%）和种子（16%）中的 P 浓度显著增加，导致 C:P 比降低。与对照相比，R5 时 eCO 显著降低了根（-4.5%）、茎（-12%）和叶（-17%）中的 N:P 比，R8 时降低了根（-26%）、茎（-57%）和种子（-22%）中的 N:P 比。此外，大豆品种对 eCO 的 C:N:P 比的响应差异很大，导致 CO 与品种之间存在显著的互作。在 eCO 下，氮而不是磷可能是大豆植株的限制因素。由于 eCO 的响应，品种间 C:N:P 比值的显著变化表明，通过选择新的品种，大豆对气候变化的适应能力可能得到提高。SN22 和 ZH4 这两个品种在响应 eCO 时 C:N 和 C:P 比值没有明显改变，因此它们可能是 eCO 适应大豆育种计划的最佳基因组。
