Phenotypic diversity and agro-morphological characterization of a global durum wheat (Triticum durum Desf.) panel using standardized morphological descriptors

Abstract Durum wheat ( Triticum durum Desf.) genetic improvement depends on the effective utilization of diverse germplasm conserved in international genebanks. Comprehensive phenotypic characterization of these resources is essential for identifying novel variation and broadening the genetic base of breeding programmes. In the present study, 708 globally diverse durum wheat accessions from the International Center for Agricultural Research in the Dry Areas (ICARDA) Global Durum Panel (GDP) were evaluated over two consecutive cropping seasons (2019–2020) under field conditions in central India using 15 standardized agro-morphological descriptors comprising 10 qualitative and 5 quantitative traits. Significant (P < 0.01) genotypic variation was observed for all quantitative traits, indicating substantial phenotypic diversity within the panel. Broad-sense heritability was high for days to heading (0.76), plant height (0.85), and grain yield (0.74), demonstrating strong genetic control of these traits. Grain yield showed a strong negative correlation with days to heading (r = − 0.80) and moderate positive association with thousand-grain weight (r = 0.46), suggesting that earlier maturity combined with heavier grains contributed to improved productivity. Cluster analysis classified the accessions into six distinct phenotypic groups, revealing considerable divergence for maturity, plant architecture, and yield-related traits. Germplasm originating from Africa and Europe exhibited the greatest phenotypic diversity, whereas superior yielding accessions were identified across multiple geographical regions, emphasizing the value of accession-level rather than regional selection. Qualitative descriptors further revealed extensive variation in plant growth habit, flag leaf characteristics, grain morphology, and pigmentation, reflecting the broad evolutionary and breeding history represented within the GDP. The observed diversity demonstrates that the Global Durum Panel constitutes an invaluable resource for parent selection, pre-breeding, and climate-resilient durum wheat improvement. The comprehensive phenotypic dataset generated in this study provides an important foundation for integrating genomic information, genome-wide association studies, and marker-assisted breeding to accelerate the genetic improvement and conservation of global durum wheat genetic resources.