Do modern winter wheat cultivars outperform traditional landraces under cold stress? A large-scale agro-morphological...

Cold stress remains a primary abiotic constraint limiting wheat (Triticum aestivum L.) productivity in high-altitude environments. While landraces represent an underexplored reservoir of adaptive traits, integrating their genetic diversity with modern breeding goals requires advanced selection tools. This study evaluated the agro-morphological performance, quality characteristics, and cold hardiness of 180 purified wheat landraces together with six registered cultivars (checks), totaling 186 genotypes from Eastern Anatolia. Using an augmented experimental design over two growing seasons in Erzurum, Türkiye, we aimed to integrate stability parameters with modern multi-trait selection indices (MGIDI and FAI-BLUP) to identify superior genotypes for continental climates. Adjusted means were obtained using a mixed model approach, and genotype effects were estimated as best linear unbiased predictions (BLUPs), which were subsequently used for multivariate analyses.

Substantial genotypic variation was observed across all traits. A significant yield gap was detected, with registered cultivars outperforming landraces in mean grain yield (2751.9 kg ha⁻¹ vs. 1556.5 kg ha⁻¹), whereas landraces demonstrated superior grain physical properties, particularly in thousand-kernel weight. Cold tolerance screening identified critical survival thresholds: all cultivars and 28 landraces survived at - 13 °C, while only seven landraces-maintained viability at - 15 °C. At - 19 °C, only the cultivar Alparslan survived. MGIDI analysis confirmed the agronomic superiority of modern cultivars (G181-G186), which ranked closest to the multi-trait ideotype at a 15% selection intensity. However, specific landraces (G81 and G173) emerged as highly divergent genotypes, successfully bridging the gap between landrace-driven grain quality and cultivar-driven cold resilience.

The integration of multi-trait indices enabled more robust identification of elite germplasm compared to traditional ranking approaches. While modern cultivars demonstrated a clear adaptive advantage in cold-prone environments, the identified elite landraces serve as valuable reservoirs of adaptive genetic variation. Genotypes G183, G181 (Alparslan), G81, and G184 are recommended as primary parental resources for breeding programs aiming to combine high yield potential with extreme cold resilience under fluctuating climatic conditions. This study offers one of the first large-scale integrations of traditional landrace diversity with modern multi-trait selection indices under extreme continental conditions, providing a practical framework for ideotype-oriented breeding in cold-prone environments.