Effect of interspecific hybridization and soil metal content on genetic variability in spruce

The effects of many biotic and abiotic factors cannot be easily assessed for long lived species such as conifers. It can however be hypothesized that long exposure to metals can result in reduction of genetic variation. Introduction of new genotypes and interspecific hybridization have been used successfully as an approach to increase genetic variability. The objectives of this study were to determine the effect of interspecific hybridization on genetic variability in P. mariana x P. rubens hybrid populations and the effect of metal contamination on the level of genetic variation in spruce species. ISSR analysis of P. mariana x P. rubens hybrids revealed polymorphism ranging from 30% to 52%. The level of polymorphism was higher with RAPD markers, ranging from 57% to 76%. Overall, no significant differences were observed among the hybrid populations analyzed for genetic variation. Metal content in soil was not associated with the level of diversity in the P. glauca populations analyzed. Genetic distance values ranged from 0.02 to 0.07 and 0.04 to 0.21 for ISSR and RAPD analysis, respectively. ISSR primers detected no difference among P. glauca populations from sites with different levels of metal content. RAPD analysis revealed a low level of population differentiation. Analysis of several generations of progeny from the samples analyzed is required to confirm the effect of interspecific hybridization and soil metal content on genetic variation.