Redefining drought tolerance in peanut: hydraulic traits emerge as field-relevant predictors

Authors: Bucior, Erika; Sorensen, Ronald; Dang, Phat; CARDOSO, AMANDA - North Carolina State University; Lamb, Marshall

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/2/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Abstract Only

Technical Abstract: Drought stress is a major constraint to peanut (Arachis hypogaea) productivity, yet current classification frameworks for drought tolerance—based on gas exchange and carbon isotope discrimination—may not fully capture field-relevant mechanisms driving yield stability. Previous studies have categorized peanut genotypes into water use strategies (e.g., isohydric vs. anisohydric) using physiological data from small plot trials. In this study, we scaled up those same genotypes into larger plot and full-field conditions over two growing seasons to test the robustness of these classifications under realistic drought stress. Gas exchange parameters (photosynthesis, stomatal conductance, transpiration) exhibited high inter-annual variability and did not consistently segregate genotypes by water use strategy. In contrast, direct measurements of soil water potential, predawn, and midday plant water potentials revealed consistent, genotype-specific hydraulic patterns during dry periods. Structural equation modeling showed clear relationships between plant water status and yield, with distinct groupings emerging along a high-to-low yield gradient. These findings suggest that physiological classifications based solely on leaf-level traits may overlook deeper hydraulic coordination mechanisms that govern drought performance at field scale. Integrating soil-plant water potential dynamics into trait screening could improve the identification of drought-resilient genotypes for breeding programs targeting yield stability under water-limited conditions.