Molecular Analysis of White Birch (Betula papyrifera) Populations From Limed and Metal Contaminated Sites in the Greater Sudbury (Ontario) Region.

The Sudbury region in Ontario, Canada has a history over the past 100 years of logging, mining and sulphide ore smelting, releasing more than 100 million tons of sulfur dioxide (SO2) and tens of thousands of tons of cobalt, copper, nickel, and iron ores into the atmosphere from the open roast beds and smelters. Although reports provide information of metal levels in soil and plants, knowledge of genetic effects on plants growing in contaminated areas is limited. The main objective of the present study was to characterize the level of genetic diversity in Betula papyrifera Marsh. (White Birch) populations from eroded and reclaimed areas using Inter-Simple Sequence Repeat (ISSR) markers. The genetic variation within and among populations were high. The percent of polymorphic loci (P %) produced by the ISSR analysis ranged from 52 % to 72 %. Shannon's information index (i) ranged from 0.22 to 0.31 and Nei's gene diversity index (h) ranged from 0.14 to 0.20. Soil analytical results revealed that total metal and nutrient in the soil matrix are not dominantly in forms available for plant uptake for all the sites. Soil pH in limed and reclaimed sites has been significantly improved. No link was found between the genetic variation in white birch populations and soil metal content. These results indicate that white birch trees in the Greater Sudbury Region are genetically sustainable.