Laboratory germination and seed bank storage of Ranunculus peltatus subsp baudotii seeds from the Tuscan Archipelago

Germination requirements and suitability for ex situ conservation were investigated for seeds from the only population of Ranunculus peltatus Schrank subsp. baudotii (Godron) Meikle ex C.D.K. Cook (Ranunculaceae) from the Tuscan Archipelago (Italy). A 2 x 2 x 3 factorial experiment investigated the interactive effects of light, alternating temperatures and mean temperature on the germination of seeds sown on agar. Logistic regression analysis showed significant effects of both temperature (P < 0.0001) and light (P < 0.05). Alternating temperatures improved germination but only at mean temperatures of 20 and 15 degrees C. The results indicate that seeds of R. baudotii exhibit morphological dormancy and a phenological adaptation to seasonal ponds. Drying led to a significant reduction in germination in seeds collected in both 2009 and 2010 (P < 0.05); the reduction was larger for 2009. The better quality of the 2010 seed was probably due to a post-harvest treatment that enabled continued maturation of the seeds. Storage of seeds for one year under seed bank conditions (-20 degrees C) did not reduce viability. Seeds of R. baudotii possess orthodox storage behaviour and are therefore suited to ex situ conservation in seed banks; however, further research is needed to confirm their long term storage prospects.