Molecular characterization of lodging resistance in bread wheat ( Triticum aestivum L.) varieties and lines using genomic SSR markers

Lodging is a critical factor limiting wheat yield and grain quality in intensive agricultural systems. Understanding the structural and genetic basis of stem stability is essential for developing lodging resilient cultivars. This study evaluated lodging resistance in 40 diverse bread wheat (Triticum aestivum L.) genotypes through an integrated approach. Morpho-physiological traits and structural stability were assessed using PBTools v.1.4, while culm anatomical parameters were measured via high-resolution microscopy. Genetic diversity was characterized using 14 polymorphic genomic SSR markers. Significant phenotypic variation was observed in plant height (73.2–131.4 cm) and basal internode diameters. Adjusted Lodging Indices (ALI) and Height adjusted lodging (HALI) identified modern semi-dwarf varieties, such as Vassa and Vexa, as highly stable Lodging percentage (LP = 1), whereas Aegilops-derived lines showed severe susceptibility (LP = 7–9). Molecular analysis showed high polymorphism (Polymorphism Information Content up to 0.95), clustering the genotypes into three distinct groups that align with their structural archetypes. Our findings demonstrate that lodging resistance is a synergistic result of reduced plant height, reinforced mechanical tissues, and specific genetic backgrounds. The identified anatomical parameters and SSR clusters provide a reliable framework for marker-assisted selection (MAS) to improve culm sturdiness in wheat breeding programs.