Elucidating the biomass and bioenergy potential of novel inter-specific sugarcane hybrids under moisture stress

Drought is a major constraint to sugarcane biomass production, necessitating the identification of resilient high-energy genotypes. This study evaluated 20 interspecific hybrids along with four commercial checks for biomass and bioenergy potential under irrigated and drought conditions during the 2021 plant crop and 2022 ratoon crop. Significant genetic variation was observed for biomass-related traits and energy yield under drought stress. The top-performing genotypes, G1 (SA 14–161), G8 (SA 14–111), and G20 (SA 14–34), consistently maintained higher dry biomass and energy production under moisture stress, retaining approximately 80–95% of their dry biomass and producing about energy about 880–1000 GJ ha −1 under drought. Correlation analysis showed that dry matter, fresh biomass, and dry biomass were strongly and positively associated. Cluster analysis grouped the genotypes into three drought-response classes, with G1, G8, G20, G15, and G5 clustering among the most drought-tolerant genotypes. Stress Tolerance Index (STI), Mean Productivity Index (MPI), Abiotic Tolerance Index (ATI), and Gold_M were identified as the most informative indices for selecting drought-tolerant, high-biomass genotypes. Genotype-by-trait biplot and cumulative ranking consistently identified G1 as the best-performing genotype, followed by G8 and G20. These superior interspecific hybrids represent promising genetic resources for developing drought-tolerant high-bioenergy cane for subtropical environments.