Influence of experimental storage conditions of spores of Floating fern (Salvinia natans (L.) All., Salviniaceae Martinov) on the reproduction of the species

Abstract

Salvinia natans is a heterospore annual aquatic fern from the Salviniaceae family. Increasing the spores’ viability by storage simulations is the basis for creating fern spore banks. In this aspect, S. natans appears to be an unconventional subject. Between October and August 2019–2020 we conducted an experiment on the storage of S. natans spore production for 4 months in 12 combinations of abiotic factors (lighting water content – temperature) and subsequent sporesgermination during the spring – summer under the same conditions of natural temperature regime, natural light and thepresence of water. The spore production viability was assessed by the time of megasporangia germination and the numberof new individuals in each storage option. We established that the of the S. natans reproduction occurs successfully witha natural combination of abiotic environmental factors – a gradually changing temperature with winter freezing, naturallight, and the presence of sporangia in water. Storage has a beneficial effect during stratification (+ 5 °C, water) and in thecombination of factors “natural temperature – dark – dry”. Early germination and the appearance of the maximum number of new individuals in these three wintering options indicate that S. natans adapts to the seasonal climate with low winter temperatures and warm summers. Dormancy of S. natans spores belongs to the forced type. Dry storage delayed germination of megasporangia for a period of two weeks to a month. The dormancy of S. natans spores belongs to the forcedtype, since the content of sporangia in water in the light and at room temperature showed the possibility of the appearanceof new individuals in October-November.