Monday, November 13, 2006

Genetic analysis of Deschampsia cespitosa populations growing in metal contaminated areas in Ontario (Canada) using ISSR markers.

Kabwe Nkongolo and Melanie Mehes. Dep. of Biology Sci., Laurentian Univ., Laurentian Univ., Sudbury, ON P3E 2C6, CANADA

The Sudbury region in Ontario Canada is known for the mining and smelting of high sulphide ores containing nickel, copper, iron, and precious metals. Much attention has focused on the environmental effects of mining and smelter pollution but knowledge of genetic effects on plants growing in contaminated areas is limited. The metal tolerance capabilities of D. cespitosa allow this species to survive on the mine tailings and the abandoned mine sites.  The main objective of the present study was to determine the level of genetic variation and the degree of relatedness within and among D. cespitosa population growing in heavy metal contaminated and uncontaminated sites using ISSR markers. Attempts were also made to determine genetic distance among D. cespitosa and D. flexuosa populations and to differentiate these two species using ISSR markers. The high accumulation of metals for several years appears to have significant impacts on the genetic structure of the D. cespitosa populations resulting in a decrease of genetic diversity.  The genetic distance data revealed that the D. cespitosa populations from Northern Ontario are different but genetically closely related.  Species-diagnostic ISSR markers differentiating D.  cespitosa and D. flexuosa were also identified.