The result of the research was the molecular-genetic characteristic of D. antarctica from the two studied regions. Data of general genome variation by RAPD study indicate that the based on their geographical location. Despite the low genetic heterogeneity, studied plants belong to two groups which correspond to their long-term isolation in the studied areas of King George Island and the Argentine Islands. All populations of D. antarctica from the two studied maritime Antarctic and South American regions were related by the sequence of ITS1-2 rDNA. It has been shown that genetically distinct plants can coexist in the near or the same areas of the Antarctic, indicating that there are no barriers to cross-breeding between the regions and the distribution of genetically distinct plants - which may be one of the factors of the success of the plant in the studied conditions.
It was found that most of the sampled D. antarctica genotypes had a diploid chromosome set (2n = 26). Nevertheless, it has been discovered and the deviation that in the harsh conditions of the Antarctica can have an adaptive effect or be the result of the influence of extreme conditions on the reproductive process. We also found plants with a mixoploid genotype bearing a near-triploid modal number (2n = 36-39), and plants of the diploid genotype with additional B-chromosomes (2n = 26 + 0-3B). In mixoploid plants with diploid modal number of chromosomes, besides aneuploidy, cells with tetraploid chromosomal numbers were found. Embryological studies of the female and male reproductive systems showed high resistance of cereal germs to adverse environmental conditions and absence of apomixis. Along with this, the development of pollen is characterized by numerous errors, which result in a large percentage of sterile pollen. The discovery of the distribution and characteristics of D. antarctica populations was detected in two distant on 400 km Antarctic regions: the oasis of Point Thomas (King George Island) and the Argentine Islands region. Significant development and coverage area of the populations (3-95%) and presence of a generative renewal of D. antarctica at Point Thomas are shown. At the Argentine Islands, the hair grass appears only on elevated areas with smaller cover (1-15%), often as an addition to the groups of carpet mosses and only in some favourable years is characterized by a generative renewal (15-30% of population).
With the presence of advanced vegetation, such as the populations of D. antarctica, more developed soils were formed at the oasis of Point Thomas (profile up to 40 cm, N 0,03-0,13%, Р 0,1-0,6%, С 0,1-2,9%) in compare with Argentine Islands region (profile up to 3-16 cm, N 2,8-4,7%, Р 0,8-9,7%, С 8,15-29,6%). The effects of concentration of trace elements, are shown, which is probably due to lesser soil profiles in the first region (Cd 0,6-29,8 mg/kg; Pb 3,1-1760 mg/kg) in the conditions of the Argentine Islands as compared with the King George Island (Cd 0,3-1,1 mg/kg; Pb 3,7-27,2 mg/kg), creates a more extreme habitat for D. antarctica in the first region.
The permanent use of D. antarctica by Dominican gull (7-42% of nesting material) was discovered in conditions of the Argentine Islands region. Distribution by natural vectors, such as the Dominican gull, can contribute to the adaptation of D. antarctica to different conditions and the colonisation of new Antarctic regions.
The reaction of populations of D. antarctica to macro-climatic changes in the region is shown. It is shown that the previously known trend towards increasing of the size of D. antarctica populations at the experimental field of the Galindez Island, as reported in 1990, did not maintain. Contrary to that, by 2016 the population has reduced in size and stabilized. Thus, the previous studies on the fitness of Antarctic vascular plants, in particular, D. antarctica and associated terrestrial flora groups; and their use as indicators of climatic oscillations in the maritime Antarctic have been confirmed.
In order to protect the populations of D. antarctica, it is necessary to set up the monitoring of human-induced impacts on the terrestrial ecosystems. To minimise the impact in accordance to the existing system of the Antarctic Treaty, it is proposed to create a special Antarctic Special Protected Area (ASPA) in the Argentine Islands region.
Throughout six Antarctic seasons of a comprehensive study of the six populations of D. antarctica growing on the Galindez Island, the United Quality Latent Index of Adaptability (UQLIA) for these populations was calculated, based on individual cover, biometric parameters, and the amount of protective and retained protein in the seeds. By this parameter, all of the studied populations showed a oscillating trend congruent with the oscillations of meteorological indices.
