The Effect of Sucrose Concentration on Ceratoperis Sporophytes

The Effect of Sucrose Concentration On Sporophyte Development in Ceratopteris Heather Forbes (Instructors: Laurie Brown and Marilyn Garne, West Iredell High School, Statesville NC)



Forbes C-Fern Culture Laboratory at West Iredell High School. Shown above (from left to right) C-Fern Growth Chamber, Sterile Transfer Chamber, and HEPA Air Cleaner.

This project involved an in-depth study of the life cycle and physiology of an unusual type of fern known as C-Fern of the genus Ceratopteris. Particular concern was given to the designing of methods to successfully culture and maintain this delicate organism. The focus then turned to study the effects of sucrose in the media on the sporophyte development of Ceratopteris. I designed and built a growth chamber and a sterile transfer/study chamber to lessen the chance of contamination and create optimal growth conditions. Both apparatuses were made from scratch with homemade materials. Spores were obtained and sown in sterile agar plates. Germination was shortly observed with subsequent development of gametophytes. At maturity, fertilization was accomplished by adding droplets of sterile water directly onto the gametophyte. Sporophyte development was soon obvious. Sterile nutrient plates were prepared with 1.5%, 3.0%, and no sucrose. Sporophytes were transferred and grown on each type of media. Sporophyte growth was measured and recorded. Results suggest that sucrose is not a desirable environment for C-Fern. Plans are underway to continue genetic studies of mutant forms of C-Fern.


C-Fern Growth Chamber (side view). Chamber consists of a large Styrofoam cooler encased in plywood with removable Plexiglas lid. The shop-light, supported by a homemade PVC pipe stand, provides continuous lighting.

C-Fern Growth Chamber (internal view). At the bottom, a ‘reptilian hot rock’ from pet store is connected to automatic switch and thermostat that maintains a constant ambient temperature of 82 °F.


C-Fern Sterile Transfer Chamber (front view) An inexpensive transparent plastic container houses a microscope and a countertop light. Two openings are made accessible by clothes dryer piping that is closed off with PVC tube covers when not in use.

C-Fern Sterile Transfer Chamber (top view) The transparent piece of Plexiglas bolted to the top allowed visibility while working inside the Sterile Transfer Chamber. Heather is busy transferring C-Fern sporophytes onto media containing various concentrations of sucrose.