Heterosis for Ethanol Yield and Yield Components in Sweet Sorghum

The improvement of sweet sorghum for biofuel traits is gaining attention globally because of its promising role in the growth and sustainability of the ethanol production chain. The aim of this study was to assess the heterosis on ethanol yield and related agro-industrial traits in sweet sorghum under tropical conditions. Thirty hybrids were generated from a partial diallel scheme using three juicy stem non-sweet female lines (A) with cytoplasmic male sterility crossed with ten sweet sorghum male fertile restorer lines (R). The hybrids, parental lines, and two checks were evaluated in three environments in Brazil. Heterosis in sweet sorghum was observed for ethanol yield (ETH) and several yield components. Four hybrids showed positive heterosis on the R-line basis for ETH. The heterosis was higher for PH (plant height), GMP (green or fresh biomass production), and tons of brix per hectare. The parental A and R-lines diverged in contributing to the heterosis. The lines BR008A and CMSXS644R have been highlighted for ethanol yield and can be included in future A and R-line development.