In the context of global warming, an important task is to find mechanisms for forest woody plants adaptation to changing environmental conditions. In steppe regions, this issue is particularly acute due to frequent droughts during the growing season. Scots pine is one of the main forest-forming species in Russia and is of great importance. The paper deals with the vital state of Scots pine plantations growing in the pessimal zone of the range in the steppe region, as well as the genotypic structure of the glutamate dehydrogenase locus. The allelic form of Gdh-1 of this enzyme is an embryonic semi-lethal for Scots pine and can act as a molecular marker of adaptation of this species to negative environmental conditions. It is known that organisms with semi-lethal genes in their genotype have a complex of compensatory mechanisms, which causes their increased resistance to adverse factors. The study sample was divided into two groups according to the level of living conditions: strong and weak. It was found that in the group of trees in the best vital condition, the proportion of genotypes containing embryonic half-life ( Gdh-1 ) of scots pine prevails. Also, in the group of strong trees, the allele, which is an embryonic half-fly, is 79%, and in the group of weak trees - 39%, which is 1,9 times less.