On the basis of the correspondence between N. I. Vavilov and G. D. Karpechenko in 1924-1926, their working relationship during this period has been analyzed. G. D. Karpechenko had just become head of a newly established genetics laboratory at Vavilov’s institute, and the director tried to help him to understand the tasks and research methodology. As a result, for the years ahead, theoretical justification and experimental implementation of new methods of breeding material development was identified. A comprehensive genetic study of the collection of plant genetic resources was made, and its further utilization in practical breeding work with major agricultural crops was worked out.

The results of the research on tracing crop wild relatives in the territory of Priazovsky State Natural Reserve are presented. Specific composition of these plants, their habitats, ecological characteristics, the rank of affinity with cultivated plants, and their economic value have been studied. The possibility of conserving priority plant species within natural plant communities is discussed.

The results of the conducted studies have shown that an excess of copper in the soil contributes to an increase of its accumulation in the soil and plant organs, which has a negative effect on plant growth and other metabolic processes, and impedes the transport of Fe, Mn and Zn in the aerial organs. Using the Cu-accumulating plants - alfalfa, clover, rape, and calendula - is one of the most promising elements of the technology of Cu phytoextraction from the soil. Two soybean varieties more tolerant to copper excess in the environment have been identified - ‘Dorintsa’ and ‘Horbovyanka’. They can be grown on soils with a high content of copper (after stubbing of perennial plants).

As a result of introductive tests of perennial Medicago species, interspecific differences in a set of traits were revealed. It was found that with the increase of the height above sea level the number of shoots on individual plant increases, while the productivity of shoots and individual plants decreases. Species, varieties and forms promising for Mountainous Dagestan were identified and selected.

Paeonia hybrida Pall., a rare species of the flora of Bashkortostan, was experimentally introduced into cultivation at the Botanical Garden-Institute, Ufa Scientific Center, Russian Academy of Sciences. The results of its study are shown, including the data of phenological observations, morphometric parameters, anthecology and elements the species’ seed productivity under cultivation. The success of its introduction into the forest-steppe region of Bashkortostan on is assessed according to a set of biological and economic characteristics. The effect of mineral supplements and synthetic growth regulators on seed production and plant habit is discussed.

Article is devoted studying of variability of cultivated plants varieties characters within their populations. The structure of ecoelements in populations of several wheat varieties of different geographical origin, with different ecological features has been studied in one climatic zone. Variability of populations phenotypical structure was investigated with use of different effects: various dates of crops sawing, temperature factors, an light mode. Various variants of variability of the investigated characters have been revealed. Results of research can be used for improvement of cultivated plants varieties quality.

Thirty-five lines from the flax genetic collection held at VIR, differing in origin and photosensitivity, have been evaluated in natural conditions of fibre flax (60°nl) and linseed (53°nl) cultivation, and in artificially created long- and short-day conditions for the duration of phases “germination-flowering”, “flowering-maturation” and plants height. It was found that within small differences in day length the main influence on the duration of vegetative period has air temperature. Under similar conditions, flax height, except for the temperature, is affected by intensity of precipitation. Additionally, the genotypes interact differently with specific environmental conditions. Therefore, conducting geographical study of a wide variability of source material will allow more efficient selection of perspective genotypes for breeding.

The results postulated a close genetic proximity of the peroxidase gene AK333699 of Triticum aestivum L. among Triticum L. species. At the same time - T. compactum Host, T. durum Desf., T. macha Dekapr. & Menabde, T. spelta L., T. turgidum L., T. urartu Thum. ex Gandiljan and T. aestivum (media genomes A^u) clustered to the subgenus Triticum. Species T. compactum, T. durum, T. macha, T. spelta, T. turgidum, T. urartu and T. aestivum (media genomes A^b) clustered together to the subgenus Boeoticum Migusch. et Dorof. Thus, the sequenced fragments homologous to the peroxidase gene TC151917 of T. aestivum and the similar peroxidase gene in another species can be identified as a separate cluster of polysaccharide-specific isoperoxidases which can bind on pathogens cell wall structures and initiate plant defense mechanisms.