The overall goal of the proposed research is to increase the biomass yield of C4 bioenergy grasses such as sorghum that are often grown in water limited environments by improving the water use efficiency, soil water extraction, and drought resilience of these crops. High biomass yield is strongly correlated with long duration of vegetative growth, however, insufficient rainfall during long growing seasons is a primary factor limiting biomass yield. To minimize this yield constraint, the proposed project will identify sorghum genotypes and traits/QTL that improve water use efficiency, soil water extraction by roots, and drought resilience. The specific objectives of the proposed research are to
(1) Screen diverse energy sorghum accessions and RIL populations for variation in traits that affect soil water extraction, water use efficiency, and drought resilience using lysimeters, aeroponics, and field experiments, (2) identify QTL/alleles and gene regulatory networks that modify expression of traits that impact soil water extraction and water use efficiency, and (3) test the utility of traits/alleles that affect soil water extraction, water use efficiency, and drought resilience in field plots under irrigated and water deficit conditions.