Pinguicula ionantha G. (Lentibulariaceae) is a federally threatened carnivorous plant occurring in historically fire-dependent bog habitats of longleaf pine savannas. The United States Fish and Wildlife Service recommends studies on seed viability, timing of germination and presence of a persistent seed bank as an aid to potential reintroduction. The objectives of this study were: (1) to compare methods to germinate P. ionantha seeds, and (2) to evaluate the existence of a persistent P. ionantha seed bank. Pinguicula ionantha seeds were collected from eleven natural populations in March-April 2012. Seed treatments included stratification (4oC for 1 or 2 months), WrightsÂ® All Natural Hickory Smoke Seasoning (dilutions of 1:100 and 1:500), plant debris smoke solutions (dilutions of 1:5, 1:100 and 1:500), plant growth regulators (Benzyladenine purine--BA, Indole-3-butyric acid--IBA or a combination), Murashige and Skoog (MS) media (Â½ and Â¼ concentrations), gibberellic acid soak (500 mg/L for 24 hours), bleach soak (10% for 10 minutes), and water soak. All trials occurred in germination chambers (16 hours light) at 25oC with germination counted daily. Seed treatments were on moistened filter paper, 1% agar, or filter paper on top of agar. Two separate seed bank studies took place with soil samples collected in February 2012 from 5 populations and in December 2012 from 10 populations. A minimum of 500 mL soil was collected from each site. Six plastic pots (3.5 x 3 cm) were filled with sterilized fine sand with a layer (100 mL) of soil sample placed evenly on top of the sand. Pots were placed in a ConvironÂ® growth chamber with 16 hours of fluorescent light at 25oC. Soils were watered daily and monitored weekly for seedling emergence. Soils were assessed for moisture, pH and texture. Highest germination was achieved with a GA3 presoak, but bleach presoak also significantly increased germination. Stratification, all smoke solutions, MS in tubes, and BA or BA + IBA produced similar germination to control. IBA and MS in plates inhibited germination. In the seed bank studies, no P. ionantha seedlings were observed. Due to the higher germination percentages with seeds sown directly on 1% agar and significantly higher germination percentages with GA3 treatments on filter paper over 1% agar, future studies might focus on combining different concentrations of gibberellic acid presoaks with seeds sown directly on 1% agar. Information may be used from these findings for potential reintroduction in areas where populations are declining or extirpated.
|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|