Genetic diversity in Spartina patens in remnant patches in the New Jersey Meadowlands

Abstract

Habitat fragmentation is a factor that influences virtually all plant and animal communities. For plants, it typically reduces the size, and increases spatial isolation of populations and causes a decrease in genetic variation. Spartina patens, a clonal and salt-tolerant grass, is commonly used in local high marsh ecosystem restoration. When an ecosystem is restored, as is the case for many urban salt marshes, the genetic profiles of plants propagules employed are often ignored. This investigation was conducted not only to identify the genetic profiles of S. patens in the Hackensack Meadowlands New Jersey for restoration, but also to understand the influence of patch size in distribution of genetic diversity of populations. To address these questions, ISSR (inter-simple sequence repeats) analysis was utilized to establish molecular genotype signatures for clones of S. patens that have been used for restoration. Approximately 83% of polymorphic bands were obtained using fourteen primer combinations. The number of polymorphic bands among the six populations/ patches ranged from 15 to 52. Shannon’s index also indicated that larger patches had higher genetic variation than small patches had. Analysis of the resulting patterns suggests that the Hawk Property Large, River Bend Small, and Fish Creek Large populations are genetically closely related. The River Bend Large population is related to Fish Small, and Hawk Property Small. This indicates that geographical distance is not related to genetic variation among populations. Based on the analysis of molecular variance (AMOVA), 58% of the genetic variation accounts for the differences among populations. It indicates that the divergence among populations is higher than the variation within population. In order to enhance the conservation of habitat of S. patens, the samples should be collected all over the mash. In this way, it may ensure the survival of the species when they were transplanted to a new habitat due to more genetic variation.