Germination responses in Callitriche truncata Gussone
Jilly Camilleri, Sandro Lanfranco
Sandro Lanfranco (email@example.com)
Callitriche truncata, Maltese Islands, germination, burial, biomass, ooding
Issue: Xjenza Online Vol. 1 Iss. 1 - March 2013
This study investigated the germination responses of seeds of Callitriche truncata, an obligate hydrophyte that colonises temporary ponds in the Mediterranean, when subjected to different depths of burial and to varying patterns of initial ooding, and to examine the effect of ooding date on the growth and reproduction effort of this plant. All investigations were carried out at two different seed densities in order to investigate whether this factor would exert any effect on germination success and on accumulation of biomass. Seeds germinated from the 'no burial' treatment and from burial under 1 cm of sterile sediment with the rates of germination success declining rapidly with depth of burial. No germination was recorded from seeds buried deeper than 1 cm. The density of seeds per pot did not in uence the results signicantly. There was no signicant difference in germination success of seeds subjected to 'Autumn ooding' and 'Winter ooding' treatments or across seed densities. Plants grown during the 'Winter ooding' treatment produced less total biomass and a lower proportion of reproductive biomass at the end of the experiment than seeds grown during the 'Autumn ooding' treatment. Although characterised by lower reproductive success, later ooding still permitted completion of life cycles and restocking of the seed bank. These ndings are generally consistent with the results of previous studies in other temporary waters of the Mediterranean.