Linda Benedict, Knott, Carrie, Utomo, Herry S., Subudhi, Prasanta K. | 1/17/2013 9:42:52 PM
Carrie A. Knott, Herry S. Utomo and Prasanta K. Subudhi
Louisiana is losing its coastal wetlands at an alarming rate. Although Louisiana has about 40 percent of the continental United States’ coastal wetlands, it accounts for 90 percent of the nation’s wetland loss. Each year numerous restoration projects are completed to protect and restore coastal wetlands in Louisiana. The most common restoration projects are involved in marsh creation, shoreline protection, river diversions, and beneficial use of dredged sediments.
Protection and restoration of Louisiana’s coastal wetlands is important for many reasons. Healthy and functional wetlands are essential to reduce hurricane and storm surge and remove contaminants from the environment. Wetlands support a significant portion of Louisiana’s economy; in 2011, revenues from industries dependent upon wetlands, such as seafood, fur, alligator, and hunting leases, exceeded $300 million. A significant portion of the oil and gas produced, refined and transported occurs within Louisiana’s wetlands. Wetlands provide food and habitat for numerous estuarine organisms and the temporary home of migratory birds and waterfowl that overwinter in Louisiana on the way to and from Central and South America. Finally, Louisiana’s wetlands protect coastal communities, industries and infrastructure vital to regional and national economies and energy security.
Plants play a major role in establishment of healthy and self-sustainable wetlands. Plants help reduce wetland loss by stabilizing and increasing soil strength with their roots. Plants also create land when stem densities are high by reducing the speed and strength of the water, capturing sediment from the water, and the decaying of the plant material. In contrast, erosion increases as the number and density of plants decrease because of increased water speed and strength and reduced production of plant material that builds organic matter and land mass. Decreased stem densities can occur for a variety of reasons, most of which are a response to environmental stresses.
The use of plants in restoration and protection projects is an extremely cost-effective and sustainable approach to rapidly increase the area of coastal wetlands and protect residents and communities of coastal Louisiana, when compared to construction projects. Most restoration projects use one clonal variety of smooth cordgrass, Vermilion, for planting because it is the only commercially available variety. When only one clonal variety is used to restore large areas, there is the possibility that the clonal variety will be unable to adapt to environmental changes, resulting in large scale death of plants. If many genetically different clonal varieties or a seed variety with a mixture of genotypes are used, it increases the chances of plants adjusting to the environmental fluctuations, which ultimately leads to successful establishment of healthy marshes.
In the late 1990s, LSU AgCenter scientists recognized that traditional plant breeding techniques could be used to develop improved coastal plant varieties. The Coastal Plants Breeding Program is the first and only plant breeding program in the nation to develop and patent native plant varieties for coastal wetland restoration. The main focus of the breeding program has been on smooth cordgrass, Spartina alterniflora, because it is the dominant intertidal saline marsh plant.
Development of Native Plant Varieties
Traditional plant breeding technologies were used to develop six smooth cordgrass varieties (Cameron, Terrebonne, Jefferson, St. Bernard, Las Palomas and Lafourche) using a recurrent selection breeding program. In 1998, the AgCenter’s Coastal Plants Breeding Program partnered with the U.S. Department of Agriculture’s Natural Resources Conservation Service (USDA-NRCS) to collect smooth cordgrass seeds from across coastal Louisiana (Figure 1). Seeds from 126 smooth cordgrass populations in 11 parishes were collected in the fall of 1998. Seeds of all populations were germinated in the spring of 1999 in controlled greenhouse conditions and evaluated for average percent germination, seedling vigor and seedling survival. Twenty populations with the highest germination, seedling vigor, and survival were selected for continued evaluations.
A total of 400 plants, 20 plants from the 20 selected populations, were evaluated in freshwater trials at the AgCenter Ben Hur Research Farm in Baton Rouge in October 1999. Plant performance was measured for the following attributes: plant height, spread, rust reaction, tiller density and plant vigor. The 40 best-performing plants, which originated from nine populations, were selected. Clonal plant material of selected plants was harvested from the field trials and used to provide plant material for additional testing.
In 2000, the 40 selected plants were evaluated in two replicated trials. One was in a freshwater trial at the Ben Hur Farm, and the other was at a created marsh site on Grand Terre Island. Plant performance was measured, and seven best-performing breeding lines were selected for additional testing.
The seven selected breeding lines were evaluated in 11 replicated trials from 2001-2009. Six of the seven breeding lines were selected for release as clonal varieties for use in coastal restoration projects in the northern Gulf of Mexico coast. The clonal varieties were named Cameron, Terrebonne, Jefferson, St. Bernard, Las Palomas and Lafourche.
The commercialization of Cameron, Terrebonne, Jefferson, St. Bernard, Las Palomas and Lafourche will require many years. The first hurdle to commercialization was to ensure that a system to maintain the purity and identify of the varieties was available. Beginning in 2008, the LSU AgCenter, USDA-NRCS, Louisiana Department of Agriculture and Forestry (LDAF) and native plant producers assembled to develop the first seed certification laws in the nation for clonal native plant varieties. After many deliberations over years, the first seed certification laws for native plant varieties were developed and adopted by LDAF in November 2012.
Once seed certification laws were adopted, plant patent applications were filed for three clonal varieties of smooth cordgrass – Cameron, Terrebonne and Jefferson – in 2012. These three varieties were released and are being distributed to interested producers.
Plant patent applications are in preparation for the remaining three clonal varieties – St. Bernard, Las Palomas and Lafourche. These varieties will be released and distributed to interested producers.
The Coastal Plants Breeding Program has developed clonal varieties of sea oats (Uniola paniculata) and California bulrush (Schoenoplectus californicus). Seed certification laws were adopted for these plants in July 2012. Plant patent applications are in preparation for three sea oats varieties, which will be released in 2013. Six California bulrush varieties are also being considered for plant patents and are anticipated for release and public distribution in 2013.
The Coastal Plants Breeding Program will continue to develop, patent, and distribute improved clonal and seed varieties of native plants for coastal restoration in Louisiana.
Carrie A. Knott is an assistant professor and Prasanta K. Subudhi is an associate professor in the School of Plant, Environmental, and Soil Sciences. Herry S. Utomo is an associate professor at the Rice Research Station.
(This article was published in the fall 2012 issue of Louisiana Agriculture magazine.)