Biotechnology...

The Newest Tool In Coastal Wetland Restoration

Artificial seed from a superior coastal wetland plant, produced by cloning large numbers of plants in laboratory dishes, could provide an important boost to CWPPRA's coastal wetland restoration efforts.

Through biotechnology, Dr. Timothy P. Croughan of the Louisiana State University Agricultural Center - Crowley Rice Research Station, and Michael D. Materne of the Natural Resources Conservation Service, Plant Materials Program, have produced individual plantlets encapsulated within a protective gel to form the equivalent of a plant-produced seed. These artificial seeds have the potential to be used as a substitute when plants fail to produce seeds naturally, or when they produce only a small number of fertile seeds. Croughan and Materne have concentrated their biotechnology efforts primarily on Spartina alterniflora, commonly known as smooth cordgrass or oyster grass.

Overcoming Poor Seed Production

Smooth cordgrass is a vigorously growing perennial grass that tolerates a wide range of water salinity and fluctuating water depths, making it an ideal species for damping wave energies and trapping suspended sediments in coastal wetlands. However, smooth cordgrass ecotypes found in the upper Gulf of Mexico basin are generally poor seed producers. Consequently, the primary method of establishing smooth cordgrass is to transplant it by hand - a costly and laborious process. The Crowley Rice Research Station and NRCS are developing the artificial seed to serve as an alternative seed source, allowing smooth cordgrass to be seeded instead of transplanted.

To produce artificial seed, small plantlets developed by tissue culturing are coated with a protective gel of varying degrees of hardness to prevent drying. Because smooth cordgrass is usually planted in aquatic or semi-aquatic conditions, its artificial seeds are coated with a relatively soft gel instead of hard encapsulation. The use of gels also provides opportunities for incorporating additives such as nutrients, fungicides and predation inhibitors into each seed gel.

Large-Scale Plantings

What does this system for cloning large numbers of smooth cordgrass plants mean to CWPPRA and other coastal wetland restoration and protection efforts? The answer is simple. Over the past few years, smooth cordgrass has clearly shown that it can reduce or control erosion in coastal wetland areas in a variety of circumstances and conditions, used by itself or in conjunction with structural measures. Using biotechnology to produce large numbers of smooth cordgrass plants from cells is a significant step toward large-scale plantings throughout Louisiana's coastal zone. In time, with the increased availability of artificial seed, innovative techniques such as aerial seeding of remote coastal marshes could be employed in the fight against coastal erosion in Louisiana.