The DNA markers for exploring of genetic resources of spruce and pine
The use of DNA markers for exploring the genetic resources of spruce and pine is discussed. Some classifications of DNA markers are considered. A brief historical review of appearance and using of different genetic markers for population genetic studies of spruce and pine is presented. The positive qualities and limitations of different types of these technics as a tools for exploring of population genetics of spruce and pine are discussed. The tendencies in changing of popularity of different DNA markers during last twenty years are noted. Different types of markers discover the differing levels of intraspecific polymorphism: low level show RAPD, RFLP and CAPS; intermediate - AFLP; relatively high - ISSR; high - SSR, SNPs and DArT. So, microsatellites and SNPs have an advantage over a number of DNA markers. The positive property of microsatellite analysis is that for every gene locus it could be determined whether the individual is heterozygous or homozygous. It is advantage comparably with RAPD, AFLP and ISSR-PCR markers. Analysis of the range of 12-17 microsatellites is the most suitable for intraspecific population studies for population genetics of pine and spruce, particularly for the analysis of genetic diversity. SNPs are very promising markers with high density through the genome and low level of mutations per generation. This method is also very good for estimation of genetic diversity. It could be easily used for evaluation of functional and neutral variability. The preliminary choice of identifying SNPs or selection of SNPs from the databases and correct statistical estimate of data become a critical points. The markers of mitochondrial DNA, on the other hand, are most useful for phylogeographic and geographical research. The species of Pinaceae have three genomes inherited by different ways: the paternal chloroplast, the maternal mitochondrial and nuclear biparental. To obtain a reliable result in population studies of pine and spruce the various independently evolving markers, for example nuclear and mitochondria or nuclear and chloroplast should be used. It allows to study genetic diversity and genetic differentiation of pine and spruce populations more correctly.