[Image: Electrophoresis of amplified DNA (PCR) products for fingerprinting analysis.]
Ida Wenefrida, Herry S. Utomo, Jennifer L. Nash and Mona M. Meche
DNA technology finds practical ways to help establish genetically diversed vegetation to restore Louisiana’s wetlands. These laboratory-derived tools can be used to address many complicated ecological issues that have been hard to quantify. Recent technical advancements have made it easier to incorporate these technologies into standard revegetation techniques. The key toward application of DNA technology for routine use is the polymerase chain reaction (PCR). It is the same technology that forensic scientists use to identify DNA fingerprints in hair, tissue or blood found at a crime scene.
Using this technology, several ecological concerns that have been increasingly emphasized in wetlands restoration can be addressed directly. DNA markers can be used to decipher some ecological components important to habitat restoration. They can be used to search for plants that have the widest genetic diversity. Genetic diversity is one of the most critical issues related to wetlands restoration. A better understanding of genetic diversity increases the likelihood of success in developing self-sustaining populations. In addition to the main goal of controlling coastal erosion through rapid establishment of marsh plant populations, efforts should be directed toward restoring ecosystem functions and processes, and, subsequently, preserving genetic diversity in the target areas.
Mapping natural gene diversity
DNA technology allows precise quantification of genetic diversity existing in the natural populations, as well as in the surrounding target areas. DNA technology is used to quantify genetic diversity of several marsh plants native to Louisiana, including smooth cordgrass (Spartina alterniflora) and California bulrush (Schoenoplectus californicus). DNA samples collected from various Louisiana coastal regions are used to determine population structure or genetic grouping among Louisiana ecotypes, and, subsequently, map geographical distribution of each major group identified. The maps will help design revegetation materials so they will have the right genetic combination to mimic the existing genetic diversity.
Designing revegetation materials for habitat restoration
By knowing the existing gene pool[Image: Extraction of DNA samples and PCR preparation to determine genetic property of marsh plants.]s, DNA data can be used to select ecotypes for use in developing cultivars that are robust and productive and have wider adaptation. Since, in most cases, genetic information of marsh plants is lacking, DNA technology becomes a valuable selection tool in genetic improvement of marsh plants. Incorporation of this technology into a conventional breeding program increases the rate and efficiency in developing superior marsh plant cultivars. Development of blend cultivars consisting of well-adapted and agronomically superior lines is essential to achieve adequate genetic diversity levels. DNA data can be used to determine the right blend or combination.
Monitoring
Following the introduction of new populations into eroding areas, DNA markers can be used to monitor population dynamics. Continuous sequential monitoring is needed to ensure stable and successful long-term coastal erosion control and saltmarsh habitat restoration. Genetic modeling to predict the effects of newly introduced plants for restoration on the existing populations can be done using DNA marker data. Genetic modeling can be used as a guide for building productive wetland plant populations with long-term viability. Sequential DNA data can reveal if necessary adjustments need to be made to obtain optimum population fitness.
Identifying m[Image: Amplified fragment length polymorphism (AFLP) analysis to evaluate genetic diversity of marsh plants. ]arsh plants fast and precisely
DNA makers can facilitate the plant material or seed certification process. Unique DNA markers associated with each superior line can be developed for regulatory purposes. PCR-based DNA markers are a relatively inexpensive, rapid and reliable method to identify plants. DNA fingerprint analysis will need only a leaf tissue sample of less than one-fourth inch in diameter. With improved equipment and methods, plant identification can be resolved within days. Using this technology, regulatory agencies will have a better handle to impose rules in coastal plant certification. Marsh plant certification will ensure that habitat restoration can be done successfully.