Dissecting the yield architecture and selecting superior seedling-derived half-sib progenies of turmeric (Curcuma...

Turmeric (Curcuma longa L.), propagated vegetatively, harbors limited genetic variability for breeding, prompting exploration of rare seed-derived half-sib progenies to generate novel recombinants. The present study investigated 263 first-generation seedling-derived half-sib progenies from five maternal accessions alongside three checks in an augmented randomized complete block design over two years (2024-2025) at Kozhikode, India. Significant genotypic variation was observed across 17 vegetative, rhizome, yield, and percentage dry recovery, with high broad-sense heritability (60-97%) for most, including total yield per plant (80.73%), primary rhizome weight (64.3%), and dry recovery (95.73%). Genotypic coefficients of variation exceeded 20% for key yield components, indicating strong selection potential. Pearson correlations highlighted strong positive associations of total yield with primary rhizome weight (r = 0.81, p< 0.01), mother rhizome weight (r = 0.60), and primary rhizome number (r = 0.57), alongside a yield-dry recovery trade-off (r = -0.20). Stepwise regression identified primary rhizome weight as the strongest predictor (adjusted R² = 0.791). Structural equation modeling confirmed vegetative growth (measured by leaf width, leaf number, petiole length) strongly influences rhizome sink strength (β = 0.860, p = 0.027), mediating indirect effects on total yield per plant. Multi-trait indices-multi-trait genotype-ideotype distance (MGIDI), multi-trait stability (MTSI), Smith-Hazel (SH), and factor analysis-ideotype (FAI)-identified 53 superior progenies (20% intensity), with 14 common selections across methods, prioritizing balanced yield, sink capacity, and stability. These findings validate seedling progenies as a practicable resource for turmeric improvement, offering observable vegetative proxies for subterranean yield traits and ideotype-based frameworks to accelerate recombination breeding.