Root system architecture (RSA) plays a central role in water and nutrient acquisition in plants. Plasticity and genetic variation in RSA can be used as an adaptive strategy to optimize plant performance under variable environments. We quantified phenotypic variation for seedling RSA among 44 diverse pea (Pisum sativum L.) genotypes, including breeding lines and germplasm accessions, grown under controlled conditions for 14 days using two-dimensional hydroponic root imaging. Root image analysis revealed significant genotypic variability among the lines for all root traits, namely root length (RL), root diameter (RD), root volume, root surface area, number of tips, network width (NW), network depth (ND), and network convex area. Significant positive correlations were observed among the evaluated root traits, ranging from 0.5 to 0.9. Pea lines were ranked based on estimated means for root traits, with lines E20, F1, and F8 showing high rankings, while E4 and F5 received low rankings for most traits. To associate root traits with nitrogen (N) fixation and field agronomic performance, we performed redundancy analysis (RDA). The quantified root traits accounted for significant variation in the agronomic traits (R² = ∼30%, p < 0.001). RDA showed a positive association between lodging susceptibility and root system NW and between plant height and root system ND. RD was positively associated with grain yield and N fixation. N fixation was positively associated with the number of lateral roots. The findings of this study indicate that variation for seedling root traits in pea could aid selection for N fixation and other important agronomic traits.

中文翻译：

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豌豆种质幼苗根结构性状变异及其与固氮和农艺性状的潜在关联评估


根系结构（RSA）在植物获取水分和养分方面发挥着核心作用。 RSA 中的可塑性和遗传变异可用作自适应策略，以优化可变环境下的植物性能。我们使用二维水培根成像在受控条件下生长 14 天，对 44 种不同豌豆 (Pisum sativum L.) 基因型（包括育种系和种质种质）中幼苗 RSA 的表型变异进行了量化。根图像分析揭示了所有根性状品系之间显着的基因型变异，即根长（RL）、根直径（RD）、根体积、根表面积、尖端数量、网络宽度（NW）、网络深度（ND） ，和网络凸面积。评估的根性状之间观察到显着的正相关，范围为0.5至0.9。根据根部性状的估计平均值对豌豆品系进行排名，其中品系 E20、F1 和 F8 显示出较高的排名，而 E4 和 F5 在大多数性状上排名较低。为了将根性状与固氮（N）和田间农艺性能联系起来，我们进行了冗余分析（RDA）。量化的根性状解释了农艺性状的显着变化（R ² = ∼30%，p < 0.001）。 RDA 显示倒伏敏感性与根系 NW 之间以及株高与根系 ND 之间呈正相关。 RD与谷物产量和固氮呈正相关。氮固定与侧根数量呈正相关。这项研究的结果表明，豌豆幼苗根部性状的变异可能有助于选择固氮和其他重要的农艺性状。