Abstract / Summary
Abstract Soil salinization threatens global maize production, yet whether maternal irrigation during hybrid seed production transgenerationally programs saline–alkali tolerance in F₁ progeny remains unexplored. This study compared maternal drip irrigation (DI) and furrow irrigation (FI), both applied at an identical seasonal quota of 4800 m³ hm⁻², during the production of two F₁ hybrids. Despite equal water supply, maternal DI significantly increased seed yield per unit area, with a 37.1 % advantage in cultivar A (14,073.50 versus 10,264.72 kg hm⁻²) and an 11.0 % advantage in cultivar B (11,207.69 versus 10,095.36 kg hm⁻²). DI also elevated thousand-seed weight (two-way ANOVA, P = 0.011) and seed pH in cultivar B (P < 0.01). Under saline–alkali stress, DI progeny exhibited superior germination speed—reaching 50 % cumulative germination approximately one day earlier and recording an approximately 8 % advantage in germination potential by day 4 in cultivar B under 180 mmol L⁻¹ alkaline stress—while simultaneously maintaining markedly stronger root elongation that intensified with stress severity, expanding from approximately 26 % under control to approximately 73 % under severe alkalinity in cultivar A. Biomass allocation further favored DI: FI progeny displayed a compensatory root-foraging surge with root-to-shoot ratio (R/S) peaking at 4.0–4.5 under 60–120 mmol L⁻¹ stress, indicating stress-induced carbon reallocation away from shoot development, whereas DI progeny maintained a balanced architecture (R/S approximately 0.5–1.5) that preserved shoot vigour while exploring deeper soil profiles. Pearson correlation matrices confirmed that DI sustained coordinated positive associations among seed size, baseline germination, and root length, whereas FI induced a zero-sum network state in which elevated R/S was strongly negatively correlated with shoot vigour (r = -0.78 in cultivar A). Notably, although FI progeny occasionally achieved marginally higher final germination percentages under specific severe stress conditions, this came at the cost of delayed emergence and substantially suppressed shoot growth, resulting in lower integrated seedling vigour. These findings establish maternal drip irrigation, under an equal water quota, as a management-level lever that enhances both seed yield and transgenerational saline–alkali tolerance in maize F₁ seed, delivering a rapid-initiation, root-robust, and growth-balanced stress-coping phenotype that outperforms furrow irrigation.