The author presents the study results concerning the infl uence of different systems of primary soil tillage on weed infestation on lands withdrawn from agriculture in Polissia of Ukraine. It is found that in case of returning such lands to use ploughing leads to depletion of weed seed stock in the layer of 0–10 cm by 36,1%. Surface and combined tillage systems help to reduce pollution of this soil layer with weed seeds by 25,4% and 31,7% respectively. When using surface tillage, a very shallow buriel of vegetative and generative organs of weeds that are close to the soil surface foster their early regrowth and accelerated development.

Abstract High-latitude environments are warming, leading to changes in biological diversity patterns of taxa. Oomycota are a group of fungal-like organisms that comprise a major clade of eukaryotic life and are parasites of fish, agricultural crops, and algae. The diversity, functionality, and distribution of these organisms are essentially unknown in the Arctic marine environment. Thus, it was our aim to conduct a first screening, using a functional gene assay and high-throughput sequencing of two gene regions within the 18S rRNA locus to examine the diversity, richness, and phylogeny of marine Oomycota within Arctic sediment, seawater, and sea ice. We detected Oomycota at every site sampled and identified regionally localized taxa, as well as taxa that existed in both Alaska and Svalbard. While the recently described diatom parasite Miracula helgolandica made up about 50% of the oomycete reads found, many lineages were observed that could not be assigned to known species, including several that clustered with another recently described diatom parasite, Olpidiopsis drebesii. Across the Arctic, Oomycota comprised a maximum of 6% of the entire eukaryotic microbial community in Barrow, Alaska May sediment and 10% in sea ice near the Svalbard archipelago. We found Arctic marine Oomycota encode numerous genes involved in parasitism and carbon cycling processes. Ultimately, these data suggest that Arctic marine Oomycota are a reservoir of uncharacterized biodiversity, the majority of which are probably parasites of diatoms, while others might cryptically cycle carbon or interface other unknown ecological processes. As the Arctic continues to warm, lower-latitude Oomycota might migrate into the Arctic Ocean and parasitize non-coevolved hosts, leading to incalculable shifts in the primary producer community.

The effect of sowing time on realization of the natural productivity potential of modern soft winter wheat varieties was studied. It is established that the use of current agricultural technologies in a context of climate change has caused shift of calendar sowing terms to the second half of the optimal terms comparing with earlier cultivated varieties. In subzones of Kirovohrad and Bila Tserkva state variety testing stations the highest yield of winter wheat is formed in case of sowing on September 20–30, but the optimum for Kirovohrad station fall on September 30, Bila Tserkva station – on September 20 and 30. Sowing in earlier or later time leads to decreasing yields, especially of Vynnychanka, Smuhlyanka, Zolotokolosa and Tripilska varieties. Bogdana and Kuialnyk varieties are the most adaptive to sowing time under agroecological conditions of Kirovohrad state variety testing station.

The effect of sowing time on realization of the natural productivity potential of modern soft winter wheat varieties was studied. It is established that the use of current agricultural technologies in a context of climate change has caused shift of calendar sowing terms to the second half of the optimal terms comparing with earlier cultivated varieties. In subzones of Kirovohrad and Bila Tserkva state variety testing stations the highest yield of winter wheat is formed in case of sowing on September 20–30, but the optimum for Kirovohrad station fall on September 30, Bila Tserkva station – on September 20 and 30. Sowing in earlier or later time leads to decreasing yields, especially of Vynnychanka, Smuhlyanka, Zolotokolosa and Tripilska varieties. Bogdana and Kuialnyk varieties are the most adaptive to sowing time under agroecological conditions of Kirovohrad state variety testing station.

The article presents the results of the laboratory investigation of the influence of high temperatures on water regime of red currant in Institute of Fruit Selection. It shows the dependence of water loss by leaves on the phenophase of plant development. High water loss by leaves occurs during the phase of ripening berries (July). Low water loss is noted during the active growth of shoots (June). Red currant genotypes: «Valentinovka», «Bayna» have a high percent of water loss in June and July. Genotypes «Shedraya», «Gollandskay krasnay», «Orlovchanka», «Dar Orla», «Selyanochka», «Osipovskay», «Belka» and «Jonker van Tets» have a low percent of loss water. The loss of water at the temperature shock is the important protective mechanism from over heat and death of plants. The results of the investigation of a degree of water restoration by red currant leaves in the periods of berry ripening and active growth of shoots are given. The most part of genotypes of red currant leaves have a high percent (>50%) of water restoration. Genotypes «Selyanochka» ,«Orlovchanka», «Dana», «Shedraya», «Belka» have a more 100% of water restoration. On the ground of the obtained results the following genotypes: «Belka», «Selyanochka», «Gollandskay krasnay», «Shedraya», «Orlovchanka», «Dar Orla», «Osipovskay» and «Jonker van Tets» are mostly heat resistant.

The article presents the results of the laboratory investigation of the influence of high temperatures on water regime of red currant in Institute of Fruit Selection. It shows the dependence of water loss by leaves on the phenophase of plant development. High water loss by leaves occurs during the phase of ripening berries (July). Low water loss is noted during the active growth of shoots (June). Red currant genotypes: «Valentinovka», «Bayna» have a high percent of water loss in June and July. Genotypes «Shedraya», «Gollandskay krasnay», «Orlovchanka», «Dar Orla», «Selyanochka», «Osipovskay», «Belka» and «Jonker van Tets» have a low percent of loss water. The loss of water at the temperature shock is the important protective mechanism from over heat and death of plants. The results of the investigation of a degree of water restoration by red currant leaves in the periods of berry ripening and active growth of shoots are given. The most part of genotypes of red currant leaves have a high percent (>50%) of water restoration. Genotypes «Selyanochka» ,«Orlovchanka», «Dana», «Shedraya», «Belka» have a more 100% of water restoration. On the ground of the obtained results the following genotypes: «Belka», «Selyanochka», «Gollandskay krasnay», «Shedraya», «Orlovchanka», «Dar Orla», «Osipovskay» and «Jonker van Tets» are mostly heat resistant.

The results obtained during observations of the growing season of pea collection varieties in different years in terms of interphase periods are presented. The dependence of the growing season length for varieties of various maturity groups on the duration of certain phases of plant growth (seedling, flowering, ripening), ambient environment (temperature, humidity, daylight hours), processing (seed preparation, line production maintenance) and genetic factors (sequential node of the first inflorescence formation) are shown. According to the study results the varieties-sources of «growing season length» characteristic were specified that have been used as components for breeding in the selection process when creating new domestic varieties.

The results obtained during observations of the growing season of pea collection varieties in different years in terms of interphase periods are presented. The dependence of the growing season length for varieties of various maturity groups on the duration of certain phases of plant growth (seedling, flowering, ripening),  ambient environment (temperature, humidity, daylight hours), processing (seed preparation, line production maintenance) and genetic factors (sequential node of the first inflorescence formation) are shown. According to the study   results the varieties-sources of «growing season length» characteristic were specified that have been used as components for breeding in the selection process when creating new domestic varieties.

The article quotes data on fruits biochemical composition for 101 varieties of peach from Nikita Botanical Garden collection. 88 varieties have been singled out according to the composition of bioactive substances. Among those varieties the North China and Iran ecological and geographical groups prevail (52.3% and 37.5%, respectively).

The article quotes data on fruits biochemical composition for 101 varieties of peach from Nikita Botanical Garden collection. 88 varieties have been singled out according to the composition of bioactive substances. Among those varieties the North China and Iran ecological and geographical groups prevail (52.3% and 37.5%, respectively).

When creating Triticum aestivum L. varieties in V. M. Remeslo Myronivka Institute of Wheat, intervarietal crossing was used as the basis for classical method of hybridization. Parental pairs were selected according to environmental and geographical principles. Crossing of lines selected by certain adaptive characteristics among themselves and with the local breeding varieties are widely used. The method of induced mutagenesis is one of the main factor of the evolutionary process which increases hundreds of times the frequency of altered forms occurrence. Thermal mutagenesis – selection of winter forms from spring varieties – is based on low temperature effect on spring wheat varieties (it was developed by V. M. Remeslo, the member of the Academy of Sciences). Method of intervarietal selection in winter wheat breeding provides creation of new varieties of this crop through mass selection of the best plants from local populations. At present, 10 varieties of winter wheat are included into the State Register of Plant Varieties Suitable for Dissemination in Ukraine, one variety – into the State Register of Breeding Achievements of the Russian Federation, seven varieties are passing state quality testing in these countries.

When creating Triticum aestivum L. varieties in V. M. Remeslo Myronivka Institute of Wheat, intervarietal crossing was used as the basis for classical method of hybridization. Parental pairs were selected according to environmental and geographical principles. Crossing of lines selected by certain adaptive characteristics among themselves and with the local breeding varieties are widely used. The method of induced mutagenesis is one of the main factor of the evolutionary process which increases hundreds of times the frequency of altered forms occurrence. Thermal mutagenesis – selection of winter forms from spring varieties – is based on low temperature effect on spring wheat varieties (it was developed by V. M. Remeslo, the member of the Academy of Sciences). Method of intervarietal selection in winter wheat breeding provides creation of new varieties of this crop through mass selection of the best plants from local populations. At present, 10 varieties of winter wheat are included into the State Register of Plant Varieties Suitable for Dissemination in Ukraine, one variety – into the State Register of Breeding Achievements of the Russian Federation, seven varieties are passing state quality testing in these countries.