Florida skullcap, Scutellaria floridana Chapm. (Lamiaceae), is a federally threatened species found in the Florida Panhandle. Its habitat is a fire-prone, longleaf pine forest dominated by wiregrass. The objective of this study was to compare techniques to break seed dormancy and to access the presence of a seed bank for S. floridana. Scutellaria floridana seeds were stratified, scarified, treated with smoke solutions, soaked in gibberellic acid (GA3), and tested for seed viability (40%). For each treatment, 3 replications of 10 seeds per plastic Petri dish on moistened filter paper were used. After dusting with thiram to prevent fungal contamination, dishes were placed in a seed germination chamber with 16 hours light at 17 Â± 3 Âµmol/m2/sec and 25o C. Germinated seeds were counted for 30 days. Arcsin transformation of germination percentages were analyzed with a one-way analysis of variance (ANOVA) at 5% level. For the seed bank study, soil samples were collected in 2 years from 8 different sites with S. floridana in Florida by scraping the soil surface near plants to collect 500 mL per site. Soil texture particles varied from 44-100% sand, 0-56% silt, and 0-38% clay. Soil pH ranged from 4-5, and soil moisture was between 17-63%. Planting pots were filled with sterilized sand and a layer of soil on top, and placed in a growth chamber at 25o C with 16 hours light at 90 Â± 2 Âµmol/m2/sec for 64 days. Six replications per site were used. Emergence was recorded as either monocot or dicot seedlings. Control seeds of S. floridana germinated significantly higher than stratification, scarification, and plant debris smoke solutions, but were similar to Hickory Smoke Seasoning and GA3. For the control, 83% of viable seeds germinated. A total of 11 dicots and 7 monocots emerged from all three sites in the first study. No seedlings of S. floridana emerged after 64 days. Seed germination for S. floridana showed the control germinated better than any of the techniques demonstrating no seed dormancy. Based on lack of dormancy, seeds of S. floridana are likely to germinate, but its seedlings were not observed in the seed bank, suggesting no seeds were present or seeds were not able to germinate and emerge in our conditions.
|Original language||English (US)|
|Title of host publication||Botany 2013, Botanical Society of America Annual Meeting; 27-31 July, 2013, New Orleans, Louisiana|
|State||Published - 2013|