Purpose. To analyze the divergence of early maturing source material of corn Zea mays L. in heterosis breeding for the genetic base formation at the State Institution the Institute of Grain Crops of the NAAS of Ukraine. Methods. Field (comprehensive assessment of morphobiological and economically valuable characteristics of the source material and maize hybrids) individual selection, cumulative and recurrent selection, backross and testcrosses bree­ding methods; laboratory; analysis and synthesis; statistical. Results. The results of research on the analysis of the divergence of early maturing corn source material in the conditions of the Steppe of Ukraine has become a developed harmonized working collection of corn breeding samples adapted to the stressful conditions of this region. The gradual cyclical improvement of the lines made it possible to form the core of the genetic diversity of FAO 150–290 early maturing specimens of the southern ecotype, which are competitive in heterosis breeding. The complexity of breeding for early maturity in the steppe conditions is due to the lack of material adapted to the stress factors of the South of Ukraine. The available early maturing lines of the world collection F2, F7, Ер1, Ма21, Ма23, Со125, Со255, См7, PLS61, S72, etc., were distinguished by high cold resistance, good starting plant development, intensive accumulation of dry matter during ripening, but not adapted to the deficiency of moisture in the soil and high summer temperatures. According to the results of the experiment, it was revealed that, in terms of breeding, lines of Lancaster plasma (DK427 and DK633) were the most plastic, due to which a number of new mid-early lines were obtained, for example DK2/427, DK267, DK266/417, DK633/266, DK296, etc., which were included in the registered hybrids. Formation of the genetic base of early maturing maize source material for heterosis breeding and systematization accor­ding to different breeding characteristics provided a balance of samples of alternative components, which will be further used to model heterosis hybrids in the early maturing group. Conclusions. The updated basic collection of lines is represented by the samples of plasma Iodent: DK744SVZM, DK216SVZM, DK4173SVZM, DK235zS, DK257zM, SV, DK365SVZM, DK777ZMSV, DK733-7zM,SV, DK315SVZM; Lancaster: DK296zS,VM, DK633/266zS,VM, DK2965ZSZM, DK2953 ZSZM, DK3023 ZSZM, DK236zS,ZM; Raid (SSS): DK232MV, DK2323MV, DK239MV; Mixed: DK253ZSZM, DK273MV, DK272zS, DK281SV, DK233zM,SV, DK959MV, DK9527 ZSZM, DK247MV, DK2442MV, which is the basis of the genetic diversity of early ripening corn samples included in the State register of plant varie­ties suitable for dissemination in Ukraine.

A stabilizing (directed) selection has created a donor of short stem for winter rye (Secale cereale L.), plant height of which ranged from 50 to 60 cm. The plant height kept symmetry of its distribution curve and the frequency accumulation in central classes (positive excess). For the first time a symbolic designation to new short-stem related Hl-2Hl-2 allele and the donor name (Gnome 2) were proposed. 28 years of stabilizing selection showed that 57% of overall genetic variability of plant height resulted from adaptive genes available for directed selection by phenotype, and 43% from dominant and epistatic factors that predetermines the expression heterosis effect. Gnome 2 donor proved to have genetic additive correlation between the pants height and number of flows per ear, ear length, weight of seeds per plant , 100 seeds weight per plant; to have reverse correlation with ear density seeds weight per ear. The height of original parent components have displayed direct additive correlation with number of flowers per ear and reverse with the ear density. The additive correlation component directly exposes «genuine» impact of parental plants on the expression of the characteristics indicated among the offspring Productive bushing of parental plants, seed weight per plant directly, and seed size (100 seeds weight) indirectly, respectively, influence the height of offspring pants. The reverse additive correlation between the parents height and 100 seeds weight in the offspring is caused by pleiotropic effect of the genes impact thus enabling to combine the desirable characteristics in one genotype. Productive bushing is by 54% due to the impact of general genetic factors among the above, in particular, 30% due to that additive, 24 due to non-additive factors. The concept of genetic improvements for productive bushing of the Gnome 2 rye implies utilization of additive effect through the directed selection, as well as application of breeding techniques for controlling the effect of heterosis caused by the genes of dominant and epistatic impact. The selection paradigm requires simultaneous genotypes selection with immediate examination of the selection results by offspring while in parallel to develop inbred lines, combining these afterwards evaluating general and specific combining ability by productive bushing. It is also to be noted that the productive bushing essentially depends on the environmental conditions, which significantly corrects the implementation of productivity potent, thereby the issue of agronomical conditions aimed at extending the expression of characteristic in question remains.

Advantages of heterotic hybrids of the winter rape in the competitive and in the production testing proven. While certain advantages in the productivity of cultivar of the Czech selection of Odila above the domestic cultivar of Dangal got in the competitive testing in the production testing confirmed. It is established that the greatest productivity in the production testing was had hybrids Vsesvit F1t Zapalnyj Fb G-3 Fi and G-4 Fi, which are characterized the stable and yearly high productivity and combine the productivity with adaptability to the environmental conditions of area of Forest- steppe of Ukraine.

Purpose. Creation of experimental sugar beet hybrid combinations of high sugar yield values and defining gene­tic determination of their heterotic effect. Methods. Diallel crossing and topcrossing, genetic analysis of quantitative traits. Results. The authors have studied the frequency of occurrence of sugar beet heterotic hybrid combinations for «sugar yield» trait created on the basis of two pollinator lines to be genetically valuable for productivity elements, CMS lines and single-cross sterile hybrids with the use of diallel and topcrossing system of controlled hybridization. The share of parental components’ effect and their interaction in CMS hybrids variability for productivity was determined. Expediency of heterotic forecasting based on high combining ability lines was substabtiated. Promising high-yielding sugar beet combinations were selected that exceeded the group standard by 4.1–16.3%. Conclusions. The theory of genetic balance by M. V. Turbin was confirmed. Such hybrids as [CMS 5OT 4]MGP 1 (116.3%), [CMS 1OT 2]MGP 1 (112.5%) and [CMS 3OT 5]MGP 1 (113.2%) were recognized as the best for their productivity, MGP 1 and MGP 2 lines – as the best for their combining ability.

The article considers the results of studying breeding material of sugar beet (MS-lines and many-seeded pollinators) of Ivanivsk Variety Testing Station in the framework of Beta-Intercross Program. Betaintercross Breeding Program for Sugar Beet has been developed by, and is implemented in, the Institute for Bioenergy Crops, formerly known as Sugar Beets Institute (ISB). Ivansivsk Variety Testing Station has been fully engaged into implementation of the Program since 1996. Key task for the Program is to draw genetic potential of breeding materials of sugar beet of the Institute research entities, namely Bila Tserkva Breeding Research Station, Ivanivsk Breeding Research Station, Uladovo-Liulinets Breeding Research Station, Uman Breeding Research Station, Ialtushkivka Breeding Research Station, as well as domestic and foreign companies with the view of maximizing the effect of heterosis use with the view of producing highly productive hybrids of new generation. Over various years, apart from various experimental re-search entities of the Institute, such companies as KWS (Germany), Novi Sad Institute (Serbia), Ramon (Russia), Danisco Seed (Denmark), Belorus ZDS and others have taken part [in the above Program]. The article provides key principles for the Program implementation scheme and its method. The cooperation has enabled to produce a range of highly productive hybrids listed in the State Register capable of competing at today’s market of sugar beet seed. Among these there are hybrids produced jointly with Ivanivsk Research Breeding Station, in particular: Romul (2005), Prometei (2008), Ramses (2009), Risolt (2007), Kvarta (2010), Zluka (2010), ITSB 0801 (2011), ITSB 0802 (2011), ITSB 0904 (2012), ITSB 0905 (2012).

500 O-type lines of sugar beet hybrid components were studied according to their main economically valuable characteristics, namely, one-seed structure, germination readiness, productivity, sugar content and sugar yield. 13 best features were determined, herewith one-seed structure of most tested genotypes was observed at the level of 92-99% which appeared to be of nearly the same level during all the years of the research. On that ground they were included into the program for further research. The weight of seeds of the researched numbers ranged from 13,3 to 22,2 gr. The productivity of the researched O-type lines varied from 40,1 to 45,2 tons per hectare. Herewith, the highest productivity index was observed in 664bk 6 line with the average index 42,7 tons per hectare which ensured sugar yield 7,59 tons per hectare. The results of the research into the influence of low temperatures on seed germination readiness and capacity of O-type sugar beet lines were given. All the researched materials readily respond to conditions of germination and the seed germination readiness and germination capacity directly depend on the temperature. However, high indices of seed germination readiness and capacity under low temperatures is an essential feature of parent breeding materials in the breeding process while creating new hybrids which can be grown by means of intensive technologies. This will make it possible to sow heterosis sugar beet hybrids in earlier terms. It was suggested to use the best lines as parent components for development of heterosis hybrids which are able to ensure seed germination under low temperatures.

Genetic and statistical analyzes of ten quantitative characteristics inheritance of reciprocal populations F2 of three-hybrid crossing by plant height, leaf blade electroidy and absence of glaucosity on the plants of Winter Rye in three breeding institutions – Nosivskiy Variety Testing Station (VTS), Verhnianskiy VTS and Volynskiy Institute APV. Major portion of phenotype variation has been determined by environmental factors. Genotype variability of those characteristics is predetermined by effects of domination and epitasis, so the breeding aimed at acquirement of heterosis effect when ZKZ (ЗКЗ) and SKZ (СКЗ) are applied is expected to be promising.

The features of sugar beet polygerm seed populations were studied. The ways of creation of combinationaluable pollenizers line –– component hybrid on sterile base were improve. The environment conditions had influenced on reaction of different types of genic interactions in specific sets of hybrids. The positive effects of interaction is a part of heterosis effects. It is proved that plasticity and stability effect depend on environment condition where genotype realization occurs.

Outcomes of reciprocal crossings new Rye donor of super-short stem with electroidness Hl-3Hl-3elel and tall Rye Variety Viatka 2 are provided. The firs generation hybrids appeared to have a short stem with regular leaf blade. In the second generation the female parent effect of short stem domination was established, as well as complete domination of tall bushiness, long-spiked plants, increased number or grains in the ear. Weight of 100 grains in the ear made 22,79 і 29, 41% of the heterosis relative to the best parent. According to the results of the research of genetic and statistical parameters of F2 breeding characteristics plants with electoid leaf blade shape were selected.

The use of regression analysis for estimation of inbred lines is a breeding - oriented method, as it indicates scientifically grounded stages of the further breeding studying of these lines and a strategy of their use. Admissible levels of inbred depression of agriculturally valuable characters are limited in lines of the Verkhnyachka and Lgov geneplasms by two - three generations of self - pollinations, which testifies to the necessity "to keep" the characters of sufficient basis. Linearity of changes of values of the characters with the advancing of inbreeding shows the absence of epistasis or the weakness of their effects which makes suitable the use of an additive-dominant model for determining breeding-genetical value of inbred lines with the aim of their purposeful hybridization for obtaining genetically determined heterosis in F1.