Identification and genetic characterization of smooth cordgrass for coastal wetland restoration

Authors: RYAN, ALICIA - LSU AGCENTER; Venuto, Bradley; SUBUDHI, PRASANTA - LSU AGCENTER; HARRISON, STEPHEN - LSU AGCENTER; SHADOW, ALAN - USDA-NRCS; FANG, XIAOBING - LSU AGCENTER; MATERNE, MICHAEL - USDA-NRCS; UTOMO, HERRY - LSU AGCENTER

Submitted to: Journal of Aquatic Plant Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2007
Publication Date: 2/28/2007
Citation: Ryan, A.B., Venuto, B.C., Subudhi, P.K., Harrison, S.A., Shadow, A., Fang, X., Materne, M., Utomo, H. 2007. Identification and genetic characterization of smooth cordgrass for coastal wetland restoration. Journal of Aquatic Plant Management. 45(2):90.

Interpretive Summary: Spartina alterniflora (Loisel.), smooth cordgrass, is a dominant perennial salt marshgrass found in tidal wetland plant communities along the Atlantic and Gulf coasts of North America. It is an important native plant species for coastal reclamation and restoration efforts. It spreads quickly by underground stems, called rhizomes, and it is tolerant of a wide range of salinity. Because of poor seed production this plant is established by transplants when used for coastal marshland reclamation or stabilization projects. The cultivar ‘Vermilion’, a vegetatively propagated clone selected for superior establishment and growth characteristics, has been widely disseminated by the Natural Resource Conservation Service (NRCS) for coastal reclamation and restoration projects along the Gulf coast. However, besides being costly and labor intensive this method of plant propagation results in thousands of genetically identical plants and can lead to a reduction in the natural genetic variation present in these ecosystems. The objective of this research was to identify plants from native populations that possessed superior traits, such as height, rate of establishment and spread, disease resistance, and seed production. It was also important that these plants be as genetically different as possible. This research did result in the identification of plants that will be used to produce a variety of smooth cordgrass that can be established from seed. This will greatly reduce the cost of establishing this plant and increase its use in reclamation and restoration efforts.

Technical Abstract: Spartina alterniflora (Loisel.), smooth cordgrass, is a dominant perennial salt marshgrass found in tidal wetland plant communities along the Atlantic and Gulf coasts of North America. It is an important native plant species for coastal reclamation and restoration efforts. It spreads quickly by rhizomes and tolerates wide range of saline, anoxic, and sulfidic soils. However, because of poor seed production this species is propagated vegetatively for reclamation or restoration projects. The objectives of this study were: 1) identify genotypes of S. alterniflora for population development, and 2) assess genetic variability of these selected genotypes at the molecular level. After three cycles of evaluation and selection, useful variation was still observed for many traits. Selection was based on plant growth characteristics and reproductive traits. Growth characters included plant height, spread, rust reaction, and vigor, and reproductive traits included seed set, germination, kernel weight, seed weight, and total seed per plant. This process resulted in seven plants, descended from seven different original source populations, which have superior performance for vegetative and reproductive traits. Molecular marker analysis revealed that genetic diversity, essential for success in the restoration projects, was maintained in selected plants. These plants will form the basis for development of an open-pollinated synthetic population of S. alterniflora intended for seed-based wetland reclamation and restoration efforts.