Multivariate Characterization and Genetic Parameters of Lodging Resistance in Maize (Zea mays indentata) Inbred Lines

Lodging, the structural failure of maize (Zea mays indentata), remains a major yield-limiting factor under diverse agroclimatic conditions. This study aimed to develop lodging-resistant S₂ inbred lines through repeated self-pollination and selection of key morphological traits, including reduced plant height, thicker stems, compact internodes, well-branched tassels, and developed brace roots. Twenty S₁ inbred lines were evaluated in a randomized complete block design during the 2024 Kharif season at Hazara University, Mansehra, Pakistan. Data on 21 agronomic and lodging-related traits were analyzed using ANOVA, heritability estimates, principal component analysis (PCA), cluster analysis, and correlation analysis. Highly significant differences (p < 0.01) were observed among inbred lines, with lodging percentage (CV = 125.83%) emerging as a key trait for improving resistance and yield stability. Mean values ranged from 259.08–396.24 cm for plant height, 2.91–3.89 cm for stem diameter, and 3600–7452 kg ha⁻¹ for grain yield. High heritability estimates for days to silking (0.94) and stem diameter (0.74) indicated their suitability for early-generation selection. PCA extracted five main components, collectively explaining 74.40% of the total variation among genotypes. Four lines (SAL-10, HUM-11, HUM-13, and HUM-14) combined high yield potential (6,700–7,452 kg ha⁻¹) with complete lodging resistance (0% LP). Cluster analysis grouped the genotypes into two clusters, with Cluster II-A2 comprising superior lines for yield stability and lodging resistance. A strong negative correlation (r = –0.58) between lodging and grain yield further emphasized the importance of structural traits in breeding for resilience. The results demonstrate that phenotypic selection, supported by heritability and multivariate analysis, can effectively accelerate the development of high-yielding, lodging-resistant maize inbred lines. These findings provide a valuable genetic foundation for breeding programs targeting resilience and yield stability in dent corn.