Current field screening methods for soybean [Glycine max L. (Merr.)] flood tolerance are time- and labor-intensive. The purpose of this research was to develop a method of screening soybean in a low-O₂ and CO₂–rich treatment using hydroponic culture in a greenhouse setting. Growth media, solution, and plant response were evaluated at various days after termination of gas treatment (DAT). Initially, a flood-susceptible genotype at early vegetative stage was subjected to a hypoxic treatment, displacing O₂ by bubbling CO₂ into the system for 5 d. The methodology was tested with 33 soybean genotypes, and normalized difference vegetation index (NDVI), soil–plant analysis development (SPAD), and foliar damage score (FDS) were measured. Then, the reaction of 17 genotypes was compared between hydroponic and field conditions. Expanded clay pebbles were identified as the best substrate for the screening method, as germination rate was not different from control. Gas treatment was shown to affect the level of dissolved O₂ in solution and to elicit phenotypic responses, of which NDVI was the most effective for differentiating germplasm, with an average of 0.29 and 0.69 for the CO₂ treatment and ambient air control, respectively (p < .0001). Also, repeatability of NDVI response across genotypes was 94.5%. Finally, preliminary field validation supported the ability of this new hydroponic methodology to separate susceptible and tolerant genotypes under hypoxia and water-logged conditions.

中文翻译：

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开发一种高通量方法在水培系统中筛选大豆种质的耐缺氧性

目前针对大豆 [ Glycine max L. (Merr.)] 抗洪性的田间筛选方法既费时又费力。本研究的目的是开发一种在温室环境中使用水培培养在富含低 O ₂和 CO _{2的处理中筛选大豆的方法。}在气体处理 (DAT) 终止后的不同天数评估生长培养基、溶液和植物反应。最初，对处于早期营养阶段的易受洪水影响的基因型进行低氧处理，通过鼓泡 CO _{2置换 O 2}进入系统 5 d。该方法用 33 种大豆基因型进行了测试，并测量了归一化差异植被指数 (NDVI)、土壤-植物分析发展 (SPAD) 和叶面损伤评分 (FDS)。然后，比较了水培和田间条件下 17 种基因型的反应。膨胀粘土卵石被确定为筛选方法的最佳基质，因为发芽率与对照没有差异。气体处理显示影响溶液中溶解的 O ₂水平并引发表型反应，其中 NDVI 对区分种质最有效，CO ₂处理和环境空气控制的平均值分别为 0.29 和 0.69。 p < .0001)。此外，跨基因型的 NDVI 响应的可重复性为 94.5%。最后，初步现场验证支持这种新的水培方法在缺氧和淹水条件下分离易感和耐受基因型的能力。