The dominant salt grass in Louisiana is smooth cordgrass (Spartina alterniflora L.). It is an ideal plant for coastal restoration and management in Louisiana because it is a native plant that spreads quickly by rhizomes and forms a dense canopy that buffers wave energy and traps soil particles that were suspended in the water. Smooth cordgrass also tolerates a wide range of salinity and anoxic and sulfidic soils, which allows it to thrive in its natural environment. Smooth cordgrass is a perennial plant that flowers annually and requires pollen from a plant other than itself to produce seed (cross-pollinated plant).
One released variety of smooth cordgrass, "Vermilion," is adapted to Louisiana’s climate and as a result is used extensively in restoration projects throughout Louisiana. The widespread use of only one smooth cordgrass variety is very dangerous because if one plant is susceptible to a particular stress -- be it disease, insect or environmental -- all plants will be susceptible to the same stress. If the stress is severe, the entire planting may die. In Louisiana, wetland loss generally precedes land loss; therefore, methods of coastal restoration that use only one variety threaten the success of restoration efforts. One solution for this problem is to plant diverse populations of smooth cordgrass at each restoration site. This will increase the odds that at least one plant in the diverse population will be resistant to the stress that is introduced. The resistant plants will then be able to spread clonally through rhizomes and repopulate areas where susceptible plants have died.
Smooth Cordgrass Breeding Methodology
The main goal of the smooth cordgrass breeding program is to develop superior, genetically diverse clonal and seed-based varieties of smooth cordgrass. The development of clonal varieties essentially involves the selection of superior lines and the maintenance of the identity of these lines. Rhizomes from plants in the wild that demonstrate desirable vegetative performance are collected. These clones are planted in field trials at various locations along Louisiana’s coast, and the vegetative performance of each clone is compared to Vermilion. Vermilion is used as the standard for smooth cordgrass because it is the only released variety. If the performance of the experimental clones is found to meet or exceed Vermilion, they will be retained within the breeding program and evaluated for their relatedness to Vermilion. If the experimental lines are found to be genetically different from Vermilion, or not very closely related, these clones will be considered for release to the public. Once clones are released to the public they are available to restoration practitioners for use in restoration projects.
Seed-based varieties utilize a polycross breeding scheme. In a polycross breeding scheme, desirable clones are identified and planted randomly in a polycross nursery. The desirable clones are allowed to randomly pollinate each other. The seed that is produced (synthetic population) is harvested. The seed will be evaluated at various locations along Louisiana’s coast for vegetative performance compared to Vermilion. If the synthetic population is found to meet or exceed the performance of Vermilion and the parental lines of the population are not closely related to Vermilion, the synthetic population will be released to the public and become available for restoration practitioners.
Coastal Plants Breeding Program
Sea Oats Breeding Program
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