Uncovering QTLs associated with agronomic traits determining biomass yield of Miscanthus sinensis

Miscanthus is a perennial rhizomatous C 4 grass primarily cultivated for lignocellulosic biomass production. Developing high-biomass-yielding varieties is a priority goal for Miscanthus breeding programs. Marker-assisted breeding represents a promising strategy to overcome the challenges in breeding Miscanthus due to its genomic complexity, short breeding history, and the extensive period required for its phenotyping. In this study, we focused on identifying quantitative trait loci (QTL) associated with biomass yield of M. sinensis through a comprehensive dissection of biomass traits into simpler components. A full-sib bi-parental F 1 M. sinensis population consisting of 278 progenies with 3 clonal replications was evaluated for 17 biomass-related traits three years post-transplanting when biomass yield was stabilized. Plant volume, stem dry weight and compressed canopy diameter exhibited the strongest correlations with biomass yield. Path analysis further revealed that the number of tillers was the most decisive trait influencing compressed canopy diameter. Through QTL mapping, 65 significant QTLs and 100 closely linked SNP markers were identified. Functional annotation of these SNPs identified 14 genes, including two genes related to lignin biosynthesis ( FAH1, SCL14 ) and five related to stress regulation ( LEN1, GRAS2, UBDK, HSP70, NLM2 ). This study provides improved phenotypic insight into biomass yield traits of M. sinensis and offers valuable trait-related markers for future Miscanthus breeding programs.