Relevance. Inbreeding is the most widespread method of obtaining starting breeding material and plays a central role in heterosis breeding programs of most crops. Beetroot inbred lines possessing economically valuable characteristics require constant maintenance via self-pollination. However, self-pollination leads to depression of a number of traits. Thorough theoretical studies and practical developments are needed to preserve valuable beetroot lines. We aimed to study the root and leaf rosette variability resulting from beetroot self-pollination. We also investigated the inheritance of monogermity in beetroots.Materials and methods. Experimental work was carried out at the All-Russian Research Institute of Vegetable Growing – branch of the Federal State Budgetary Scientific Institution "Federal Scientific Vegetable Center" (FSBSI FSVC), 2011-202], Moscow Region. The object of the study was inbred beetroot lines originated from beetroots of foreign selection. The research data were obtained via field observations and measurements.Results. It has been experimentally shown that the constant signs of self-pollinated beet lines of 1 year of life are the position and height of the leaf rosette. Stabilization and maintenance of separate fertility at a high level is carried out by selection. A negative correlation was noted between the signs of the degree of separateness and the height of the leaf rosette of the plant, the proportion of the neck of the root crop in its diameter, the mass of the root crop and the proportion of the root crop in the biomass of the plant in the offspring of the fourth generation of the inbreeding. The decrease in the productivity of the seed plant occurs at the beginning of the process of creating self-pollinated lines – in the first generation.

One of the main directions of onion crops breeding in the world is heterosis breeding. Heterosis hybrids occupy the main place in the commodity production of onions in the Netherlands, USA, Japan and other countries. In State Register for Selection Achievements Admitted for Usage (National List) of the Russian Federation, admitted to use in 2018, made 378 cultivar of onions, including 188 (49.7%) – F1 hybrids, of which 140 – foreign breeding. A common way to create heterosis hybrids F1 onions is the use of lines with cytoplasmic male sterility (CMS) as one of the parent forms. The article presents the results of multi-year research of the laboratory of breeding and seed production of onion cultures (VNIISSOK, now FSBSI FSVC) to assess and highlight the lines of CMS onions with high combinational ability, the creation of heterosis hybrids on their basis. In 2002-2005, 229 cultivar of onion were studied to identify plants with pollen sterility and maintainer. 515 plants with CMS were isolated. In the subsequent years (2006-2010) was established 1588 maternal lines (S msms) and the fathers of maintainer (N msms). To obtain F1 hybrids with the maximum level of heterosis, the combined ability of lines and pollinators was evaluated by topcross and diallel crosses. The best lines for the complex of economically useful features with high combinational ability were included in various combinations of crosses with inbred lines in order to select high-performance hybrid combinations and to create F1 hybrids. 547 combinations of crosses of sterile lines with inbred paternal lines were carried out, on the basis of which 408 F1 hybrids were created. After testing and evaluation of them in the hybrid and breeding nurseries allocated 23. According to the results of the competitive test samples were identified, which under the names of Logran F1, Zarnitsa F1 and Solnyshko F1 transferred to the state variety test.

Beet is considered a difficult breeding object due to its biological peculiarities that make it difficult to obtain hybrid seed progeny. In cross-pollinated crops, the maximum hybridization is achieved by using sterile mother plants, which are extremely rare in the nature. Inbreeding is one of the ways to isolate genotypes with cytoplasmic male sterility, which are controlled by recessive alleles of nuclear genes and S-factor of mitochondrial DNA, from a complex heterogeneous population. The main distinguishing features allowing to identify plants with male sterility are the structure and coloring of anthers, and the quality composition of pollen. The diversity of phenotypic manifestation of marker coloration in sterile anthers is determined by the ratio of different pigments. Diversity of pollen grains of fertile and sterile plants is caused by differences in their development at the late stages of androgenesis. The degree of sterilization varies in different genotypes, which is associated with complex regulatory mechanisms of interaction between the genetic apparatus of the nucleus and the cytoplasm. Along with abnormalities of pollen grain micropopulations, self-fertilization results in morphological changes in the structure of inflorescences and number of flower organs, which has a direct impact on the seed productivity of plants. The studies summarized in this publication are relevant and essential for the search of effective ways to control plant development in ontogenesis and universal selection criteria in the process of creating fundamentally new forms of plants, which is especially important for breeding.

The paper presents the stages of creating bulbous forms between A. cepa L. and A. Vavilovii Pop. et Vved. through hybridization, in vitro embryo culture, backrossing, inbreeding and cross-breeding. As object of research were considered inbred progeny I1-5   from BC1-2F5  combinations of crossing of A. cepa x A. Vavilovii.  The parent species A. cepa L. of the onion variety Odintsovets was the standard. In plants of the first year of vegetation studied signs: the color of dry scales of the bulb, the weight of the bulb, the index of the bulb shape and the number of leaves. Phytopathological assessment of onion plants for resistance to downy mildew (peronosporosis) was carried out. In the progeny of  interspecies hybrids plants were aligned on the color of the bulb (yellow and brownish). The average weight of the bulb varied from 33.5 to 92.3 g in generations I1-5  from ВС1, and in generations I1-5  from ВС2 it varied from 22.1 to 93.6 g. plants of bulbous forms had a flat bulb (I=0.6-0.7). Only plants from the progeny I3   and I5   from BC2 formed rounded-flat bulbs (I=0,8-0,9). The number of leaves in bulbous plants in the progeny varied on average from 5.3 to 7.1 PCs. The score of peronosporosis was low and medium (0.5-1.0). Was selected form of inbred progenies of I1-5   from BC1-2  with a dense bulb is flat and round-flat shape, which combined a relatively high resistance to downy mildew with a mature bulb is capable of storing.

The protected cultivation technology, through which the various inbred generations with the combination of economic valuable traits and different level of sterility can be produced, is used in order to accelerate the breeding program. However, there is a negative effect of inbreeding depression and self-incompatibility can often occur and cause the loss of valuable breeding forms. The aim of the work was to study the influence of steroidal glycosides capsicoside (SGC) on exhibition of CMS, and morphobiological parameters of 13 inbred generations that were produced from fertile plant and partly sterile plants with level of sterility 10% and 50%. The seeds were soaked for 24 hours in water solution of SGC with concentration 10-3%, and in water control. Then the seeds were dried up and sown in the greenhouse. The stecklings and roots obtained were vernalized at 3-5Co. Mother plants were grown under 18 hour photoperiod in greenhouse with supplementary lighting. Inbreeding seeds were obtained in individual cloth isolators. It was shown that for all generations the treatment with SGC improved the seed germination (4-8% more), increased the root index and its length (12-24% more), decreased betanin content (22-48% less) in comparison with control. The action of SGC on the other morphological and biochemical traits such as height of leaf rosette, leaf number, plant and root weight, head size, number of generative buds, and nitrate content was defined by the level of sterility of mother plant. The most expressed effect for all traits mentioned was seen in inbreeding generations of sterile plants with high level of sterility. After action effect of seed treatment with SGC on development of seed plants from inbreeding generations, not depending on sterility level of mother plants, showed the positive influence on plant habitus of seed mother plants, decreasing the plant height, but increasing stem number and functional parameters of microgametophyte in fertile plants. This caused the improved seed formation 1.6-2.2 times higher during inbreeding process and increased the portion of plants with high productivity. The SGC had no effect on exhibition of CMS trait. Thus, the SGC is worth using in valuable highly inbreeding forms inclined to self-sterility, in order to enlarge the genetic variation and output of divers generations. However, it should be taken into consideration that the complicated effect on the plant traits can be noticed in inbreeding generation of red beet and may have an effect on the result of selection process at the root stage.

One of the way of increasing of genetic variability of onion (Allium cepa L.) is the interspecific hybridization. Development of onion interspecific hybrids consists of the study of initial breeding forms, its heterogeneity, ways of crossing and pollination, overcoming of outbreeding problem, sterility and weak fertility of the hybrids of first and next generations, specifics of hybrid’s seeds development, identification and selection of recombinant forms with breeding valuable traits. The stages of development of the bulbous forms of interspecific hybrids of onion are presented in the article. The study was conducted in the “All-Russian Scientific Research Institute of vegetable breeding and seed production” of the Moscow region. The plants of inbreed progenies I1-5 from BC1-2F5 of bulb forms of interspecific hybrids A. cepa х A. Fistulosum as well as the parental forms were analyzed. The breeding and phytopathological assessment of recombinant forms of onion interspecific hybrids was done for qualitative and quantitative traits and for resistance to downy mildew. Using the individual selection for quality and quantity traits, it was found that the forms, whose traits were not undergo the inbreeding depression because of the higher homozygosity can be used for development of linear initial material for breeding for heterosis. The forms with the inbreeding depression have to be used for crossbreeding. Along with increasing of homozygosity, the new modified genotypes appear because of potential variability and genes recombination. It allows to make the purposive selection of recombinant forms for valuable traits. The selected onion forms from inbreed progenies of I1-5 from BC1-2F5 which have bulbs of flat and well-rounded-flat shape are characterized by high resistance to downy mildew and bulbs with good storage ability. The selection process of the recombinant forms from progenies of onion interspecific hybrids obtained based on repeated inbreeding is shown. Using such techniques as stage-by-stage crossing of A. Cepa L. and A. fistulosum L., embryo culture, polyploidization, backcrossing, inbreeding, selection of recombinant forms, etc., the technology of creation of new initial breeding material of onion was developed.

The results of complex estimation of structure of variety population Amager 611, the genetic analysis by inbreeding (J1-J9) and RAPD-markers are shown. The role of 17 phenotype groups in the variety population was determined. The suggestions for agriculture and maintaining of cv. Amager 611 are proposed.