Figure 1 in Morphogenesis of Ulva mutabilis (Chlorophyta) induced by Maribacter species (Bacteroidetes, Flavobacteriaceae)

Figure 1: Control experiment for complementary activity of morphogenesis-inducing bacteria (reference strains). Axenic Ulva mUtabilis sl G mt(+) germlings (A) were inoculated with either RoseovariUs sp. MS2 (B) or Maribacter sp. MS6 (C) or both bacteria (D). Gametophytes were propagated for gamete production and release under laboratory conditions (Wichard and Oertel 2010). Afterwards axenic gametes were prepared according to Wichard (2015). Purified gametes [mating type (+)] were inoculated with selected bacteria (final concentration OD = 1 × 10 − 6) in 10 ml Ulva culture medium and kept in the dark for 24 h to let gametes settle on culture tissue flask. After 14 days 600 growth at 18°C and 90–120 µmol photons s− 1 m− 2 for 17 h light and 7 h dark, thallus development of 50–70 germlings derived from triplicate experiments was examined with an inverted Leica DMIL LED microscope (Leica, Solms, Germany) equipped with a digital camera (Nikon, Düsseldorf, Germany). The four morphotypes are colour-coded. Black arrows indicate protrusions from the exterior cell wall. Scale bars = 100 µm.