Energy cane as a strategic bioenergy crop: Global development, breeding advances, and sustainable bioenergy prospects

Energy cane, a Saccharum hybrid bred primarily for enhanced biomass rather than sucrose content, has emerged as a strategic bioenergy crop addressing global demands for renewable and sustainable energy. Originating from hybridization between commercial sugarcane and wild relatives such as S. spontaneum , S.robustum, Erianthus sp. and Miscanthus sp., energy cane exhibits a high fiber content, greater stress tolerance, and biomass productivity. These characteristics make it a desirable feedstock for integrated 1G and 2G bioethanol production and cogeneration with 80% lower GHG emissions as compared to fossil fuels. Its cultivation on marginal lands with reduced competition for food production further lowers its carbon footprint. Contemporary studies classify canes into four main types: conventional commercial cultivars of sugarcane with high sucrose (Type I), multipurpose canes with fiber content greater than 20% and similar sucrose levels as sugarcane (Type II), and specialized cane types with fiber content greater than 22% and much lower sucrose levels intended primarily for 2G bioethanol and cogeneration purposes (Types III and IV). This review synthesizes the history of energy cane development, current global advances in breeding energy cane genotypes, released varieties, their distinct genetic backgrounds, and breeding objectives across Brazil, the USA, India, and Thailand. This study also documents ongoing research and experimental clones in other countries, such as China, Australia, Argentina, and South Africa. A country-wise comparative analysis underscores the variation in fiber content, sucrose levels, and biomass yield shaped by diverse parental lineages and agro-climatic priorities. Overall, this review highlights the strategic importance of transitioning to energy cane as a multipurpose biomass crop with significant potential for climate change mitigation, the global bioeconomy, and sustainable biofuel options.