Evaluation of drought resistance in seedlings of eight switchgrass accessions

Switchgrass (Panicum virgatum) is one of the important energy grasses, and the drought resistance of its seedling stage plays a key role in growth under arid and semi-arid conditions. Therefore, selecting switchgrass genotypes with good drought tolerance in the seedling stage is important. In greenhouse experiments, we tested eight physiological indicators related to drought resistance, including superoxide dismutase and peroxidase activity, free proline, soluble protein, soluble sugar and leaf water content, relative electrical conductivity, and malondialdehyde levels. In addition, we evaluated the drought resistance of eight switchgrass varieties chosen from American gene bank by subordinative function value analysis. The results showed that the eight accessions compared differed significantly in drought resistance at seeding stage. The drought resistance ranking was as follows: Shawnee>Cave-in-Rock>Blackwell>BN-309-69>Trailblazer>Carthage>TEM-SLC>Grenville. The results provided a theoretical basis for developing switchgrass breeding programmes aiming to improve drought resistance, and valuable information for planting switchgrass varieties in marginal lands.