HYDROGEN PEROXIDE AND COLOR SORTING IMPROVES GERMINATION AND VIGOR OF EASTERN GAMAGRASS (TRIPSACUM DACTYLOIDES) SEEDS
Eastern gamagrass (Tripsacum dactyloides) is a warm-season perennial grass used for forage, as an ornamental grass in landscapes, and for conservation plantings. The seed is encased in a cupule and requires cold moist stratification for germination, which rarely exceeds 60%. The objective of this study was to investigate cupule color as a marker for germination in seeds treated by stratification or hydrogen peroxide (H2O2). Cupules of Pete and Highlander varieties were visually separated into green, medium, and dark categories. Seed and cupules for each category were measured for chlorophyll content, size and weight. Seed-containing cupules were stratified for 6 weeks at 4°C or were soaked in 0 to 30% H2O2 for up to 48h and then germinated at 20°C/30°C (12h: 12h) in the dark. Dark cupules and seeds were heavier, larger, and had less chlorophyll than medium or green. Green seeds had the lowest germination percentage and shortest shoots regardless of treatment. Soaking in 15% H2O2 for 18h broke dormancy most effectively. Seed-containing cupules treated with H2O2 germinated within two weeks, while isolated seeds began germinating within 4 days, indicating that the cupule is at least partially responsible for dormancy. Rigorous sorting of gamagrass cupules by color or weight will improve the germination and vigor of the resulting seedlot. Treatment with 15% H2O2 for 18h can substitute for six weeks of stratification at 4°C in satisfying dormancy of eastern gamagrass.
Klein, J.D., Wood, L.A. and Geneve, R.L. (2008). HYDROGEN PEROXIDE AND COLOR SORTING IMPROVES GERMINATION AND VIGOR OF EASTERN GAMAGRASS (TRIPSACUM DACTYLOIDES) SEEDS. Acta Hortic. 782, 93-98
physiological dormancy, stratification