Sweet sorghum for phytoremediation and bioethanol production

As an energy crop,sweet sorghum(Sorghum bicolor(L.) Moench) receives increasing attention for phytoremediation and biofuels production due to its good stress tolerance and high biomass with low input requirements.Sweet sorghum possesses wide adaptability,which also has high tolerances to poor soil conditions and drought.Its rapid growth with the large storage of fermentable saccharides in the stalks offers considerable scope for bioethanol production.Additionally,sweet sorghum has heavy metal tolerance and the ability to remove cadmium(Cd) in particular.Therefore,sweet sorghum has great potential to build a sustainable phytoremediation system for Cd-polluted soil remediation and simultaneous ethanol production.To implement this strategy,further efforts are in demand for sweet sorghum in terms of screening superior varieties,improving phytoremediation capacity,and efficient bioethanol production.In this review,current research advances of sweet sorghum including agronomic requirements,phytoremediation of Cd pollution,bioethanol production,and breeding are discussed.Furthermore,crucial problems for future utilization of sweet sorghum stalks after phytoremediation are combed.