[Comparative sequence analysis of the LEA gene fragment in Pinus sibirica du tour and Pinus pumila (Pallas) regel].

A comparative sequence analysis of the LEA (Late Embryogenesis Abundant (LEA)-like gene) intron fragment was performed in Pinus sibirica and P. pumila differing in geographic origin. It was demonstrated that in P. sibirica this fragment was represented by two types of PCR products, 224 and 202 bp in size. Similarly, in accessions of P. pumila, two PCR products of 224 and 159 bp in size were identified. Comparison of 224 bp fragments in P. sibirica and P. pumila showed that they differed in single nucleotide substitutions. Analysis of the intron fragment in a plant, which was characterized as an interspecific hybrid based on morphological characters, showed that it had fragments of 224 and 159 bp in size. The sequence of 224 bp fragment was similar to that of the corresponding fragment in P. sibirica. The structure of the short fragment was the same as the structure of the corresponding fragment in P. pumila. The data obtained are discussed in terms of the use of the sequences examined for species taxonomic classification and of an analysis of species hybridization.

[Distribution of the genetic diversity of the Siberian stone pine, Pinus sibirica Du Tour, along the latitudinal and longitudinal profiles].

The Siberian stone pine (Pinus sibirica Du Tour) is one of the main forest-forming coniferous species of the boreal ecosystems of Western Siberia. We used the isozyme method to analyze 11 ecotypes representing the latitudinal and longitudinal profiles within the species range, including samples from the geographic boundaries of the distribution. The genetic structure of the ecotypes is described on the basis of the variability for 26 isozyme loci encoding for 16 enzyme systems. The greatest genetic diversity was observed in the taiga ecotypes in the central part of the studied area, while the ecotypes along the species range boundaries were shown to be genetically depauperized. Approximately 8.1% of the observed genetic diversity is attributed to differences between the studied ecotypes. We detected high levels of genetic diversity for the Fest_2, Pgm_1, Sod_4, and a few otherloci, as well as a correlation between allele frequencies and geographical locations of the populations. The results of multivariate analysis of allelic frequencies as well as cluster analysis allowed us to discriminate three major groups of ecotypes: north-eastern, central and south-western. In view of our results, we compare two hypotheses: one which attributes the spatial distribution of genetic variations to the selectivity for some of the polymorphic allozyme loci, and the other based in the history of the formation of the range of the Siberian stone pine.