Hayati Akman
Wheat root systems are critical for water and nutrient uptake, yet they remain an underexplored "hidden half" in breeding programs.Ancient wheat relatives may harbor valuable root traits for climate resilience.This study aimed to investigate phenotypic diversity in root and shoot traits among modern and ancient wheat genotypes (T.aestivum, T. durum, T. polonicum, and T. turanicum) during the stem elongation stage to identify genetic resources with superior root characteristics.Twenty-five wheat genotypes were grown in 100 cm PVC tubes under controlled greenhouse conditions.Root and shoot morphological traits were measured at the stem elongation stage, including rooting depth, biomass allocation, tiller number, and plant height.Significant genotypic differences (P < 0.001) were detected for all traits.T. turanicum accessions (CItr 11390 and PI 166308) displayed greater rooting depth than modern wheats and T. polonicum accessions.For root biomass, T. polonicum (PI 192666) and T. turanicum (PI 166450 and CItr 14082) accessions showed substantial root biomass accumulation relative to modern wheats.The hierarchical clustering dendrogram demonstrated a close association between traits, specifically grouping root biomass and shoot biomass within the same sub-cluster.Phenotypic grouping indicated a substantial extent of within-species plasticity.Ancient wheats, particularly T. turanicum and T. polonicum, offer valuable genetic resources for improving root architecture.Ancient wheats harbor valuable root traits that could be introgressed into modern varieties for wheat improvement.This study suggests that deep-rooting accessions are particularly advantageous for improving new varieties for rainfed conditions, whereas large-rooted accessions should be prioritized for yield evaluation, with the breeding goal of assessing their relative suitability under irrigated versus rainfed conditions.