Growth and Timing of Gametophyte Development

Under standard culture conditions (temperature and illumination), spore germination and gametophyte development occur in a consistent pattern.

Figure 1. C-Fern life cycle and timing of developmental events in cultures starting from single-celled spores

Developmental timing depends on culture under standard temperature and light conditions, i.e. in the C-Fern Growth Pod a temperature of 28 °C and light provided by 15 W fluorescent bulb in a reflective fixture. Under these conditions, the principal developmental events occur in a predictable sequence.

  • Spore germination is first evident three to four days following spore soaking (DFS)
  • Spore germination is complete by six to eight DFS.
  • Male and hermaphroditic gametophytes are sexually mature at 10 to 12 DFS. This is the best time to observe fertilization or to perform cross or self-fertilization for sporophytes. As gametophytes age,  effective spermatozoid production decreases.
  • Multicellular embryonic sporophytes are evident under a microscope by about 15 DFS
  • Subsequent sporophyte development over the next 75 days, i.e. the production of sterile leaves (fronds) followed eventually by the production of fertile leaves with the production and release of spores.