Identification of promising sweet sorghum advanced lines for bioenergy production under Mediterranean conditions

Sweet sorghum (Sorghum bicolor L. Moench) is one of the most important renewable bioenergy crops that have high biomass production capacity and high sugar content in stems. The aim of this study was to identify promising lines derived from a recombinant inbred population with greater potential for bioenergy in Mediterranean conditions through an initial, line-level evaluation under the target environment. Twenty-four genotypes derived from a recombinant inbred line (RIL) population were evaluated during the growing seasons of 2021 and 2022 under Mediterranean field conditions. These lines were derived from crossing “Erdurmus” (sweet sorghum) with “Ogretmenoglu” (grain sorghum). There was significant genotypic variation for all bioenergy-related traits, including plant height (PH), stem diameter (SD), fresh biomass yield (FBY), stem yield (SY), Brix (BX), and plant juice content (JC). Heritability varied from 0.17 for JC to 0.91 for PH. The high values for PH and BX indicate strong genetic effects, and the positive correlations between PH, FBY, and SY show that these traits can be beneficial for selection when evaluated in combination. Principal component and cluster analyses classified genotypes that had greater potential for producing more biomass and sugar and revealed distinct trait-based groupings among lines. Several lines, particularly Srg174, Srg334, and Srg351, performed better than the check cultivars for one or more bioenergy-related traits under the conditions of this study. These lines can be helpful for breeding because they can be used for developing high-yielding cultivars with promising performance under Mediterranean conditions for sustainable bioenergy production and represent valuable genetic material for further advancement in bioenergy-oriented sorghum breeding programs.