Relative Salt Tolerace of 33 Switchgrass Cultivars.

Switchgrass (Panicum virgatum) is a warm-season C4 grass that is a target lignocellulosic biofuel species. Salt stress is one of major limiting factors for switchgrass in many regions. The objective of this study was to examine relative salt tolerance of 33 switchgrass cultivars. Seeds of each variety were planted in conetainers and grown in greenhouse. Two months later, the grass was grown in half strength Hoagland’s nutrient solution (control) or half strength Hoagland’s nutrient solution with 200-300 mM NaCl (salt stress treatment) for 24 days. Salt tolerance was determined based on various parameters including photosynthetic rate, stomatal conductance, photochemical efficiency (Fv/Fm), electrolyte leakage, and chlorophyll content. The results showed that there were significant differences in salt stress tolerance between varieties. Among the 33 varieties, Alamo, Kanlow, TEM-LoDorm, T-2101, BN-13645-64 and T-2086 had relatively good salt stress tolerance; in contrast, Blackwell-3, 70SG0021, Pathfinder, Shawnee, 70SG0016, T4614,70SG003,T16971, and BN-18757-67 had relatively poor salt stress tlerance.