Work

Multivariate phenotypic profiling identifies drought-tolerant bread wheat germplasm through sequential seedling and field-stage screening

Year: 2026

Type: article

Abstract: Drought is a major abiotic constraint on wheat ( Triticum aestivum L.) productivity in semi-arid regions, and identifying drought-tolerant germplasm is a prerequisite for developing climate-resilient cultivars. In Phase 1, 400 spring wheat genotypes were evaluated at the seedling stage under three moisture regimes (100%, 70%, and 40% field capacity) using a completely randomized design with three replicate pots per genotype × treatment. Ten morpho-physiological traits were recorded. Drought significantly reduced seedling growth (mean seedling length declined from 40.0 cm to ~ 29 cm; P ≤ 0.01) and increased proline content approximately 5.5-fold ( P ≤ 0.01), with no statistically significant difference between the two drought levels for the growth traits. The first two principal components jointly explained ~ 40% of the seedling-stage variation across all moisture regimes, and five components were required to explain > 70%. Based on an integrated ranking of standardized trait means, PC1/PC2 scores, and hierarchical-cluster membership, 105 lines were advanced to Phase 2 field evaluation under full irrigation, drought at anthesis, and drought at grain development. At the field stage, the contribution of PC1 declined from 60.96% under full irrigation to 22.47% and 30.26% under anthesis- and grain-development-stage drought, respectively, indicating a redistribution of phenotypic variance across a larger number of independent axes under stress. Sequential multivariate profiling identified a phenotypically diverse subset of Pakistani wheat germplasm suitable as parental material for a Line × Tester crossing programme aimed at drought resilience. The pronounced stage-specific reorganization of the phenotypic structure highlights the multi-trait, multi-stage nature of drought adaptation and cautions against reliance on single-trait or single-stage selection. Not applicable.

Source: BMC Plant Biology

DOI: 10.1186/s12870-026-10121-8