Identification of SNPs Associated with Drought Resistance in Hybrid Populations of Picea abies (L.) H. Karst.–P. obovata (Ledeb.)

Background/Objectives: The spruces of the Picea abies–P. obovata complex have a total range that is the most extensive in the world flora of woody conifers. Hybridization between the nominative species has led to the formation of a wide introgression zone, which probably increases the adaptive potential of the entire species complex. This study aimed to search the genes associated with drought resistance, develop primers for the informative loci of these genes, identify and analyze SNPs, and establish the parameters of nucleotide diversity in the studied populations. Methods: The objects of this study were eight natural populations of the spruce complex in the Urals. Nucleotide sequences related to drought resistance spruce genes with pronounced single-nucleotide substitutions were selected, based on which 16 pairs of primers to their loci were developed and tested. Results: Based on the developed primers, six pairs of primers were chosen to identify SNPs and assess the nucleotide diversity of the studied populations. All selected loci were highly polymorphic (6 to 27 SNPs per locus). It was found that the Pic01 locus is the most variable (Hd = 0.947; π = 0.011) and selectively neutral, and the Pic06 locus is the most conservative (Hd = 0.516; π = 0.002) and has the most significant adaptive value. Conclusions: The nucleotide diversity data for the studied populations reveal similar values among the populations and are consistent with the literature data. The discovered SNPs can be used to identify adaptive genetic changes in spruce populations, which is essential for predicting the effects of climate change.