Selection ideatype of a new variety of oil flax adapted to forest-steppe conditions

Размещено на http://www.allbest.ru/

Размещено на http://www.allbest.ru/

Selection ideatype of a new variety of oil flax adapted to forest-steppe conditions

Zaika Ye.¹, Drozd O., Kondratyuk V., Pyvovar T.

NSC «Institute of Agriculture NAAS»

Goal. To create a new ideatype of oilseed flax, which will increase seed production in the Forest- Steppe with high yields, seed quality, and disease resistance. Methods. Field method -- to determine the interaction of the subject of research with natural and agronomic factors; measuring and weighing -- to determine the height of plants, yields of straw, fiber, seeds; settlement-comparative -- for the economic evaluation of cultivation of different varieties of flax; statistical, dispersion -- to identify the reliability of the results of experiments. Results. Based on field researches of the registered modern varieties of oil flax the key economically valuable signs which were used for the creation of a selection ideatype of a variety of oil flax adapted to the Forest-Steppe zone are allocated. Valuable selection lines of oil flax, which have a set of valuable features and significantly exceed the variety standard for productivity, are selected according to the main parameters of the ideatype in the selection process. Conclusions. Based on field researches and data of laboratory analysis the selection ideatype of a variety of oil flax adapted to conditions of the Forest- Steppe zone is developed. The proposed model can be used at the preparatory stage of selection -- in the selection of parental forms for crossing, and directly in the selection process --in the selection of plants among different generations of hybrids in selection nurseries, and in the assessment of the resistance of varieties to biotic and abiotic factors, which was used in selection work of the NSC “Institute of Agriculture of NAAS”. selection yield oil content

Key words: selection, yield, oil content, lodging.

Flax (Linum usitatissimum) is a valuable oilseed crop that has long been used by humans. Flax was grown as early as 6 - 8 thousand years ago in Egypt and Samaria, and from there it was brought by trade routes to Western Europe in the 5th-3rd millennium BC for the obtaining the expensive oil from seeds[1,2]. With the mowing to the eastern regions of Europe, flax began to be used more to produce a bast fiber, from which cloth was made [3]. Now the geography of flax cultivation covers almost the entire Earth globe. Canada, China, Ukraine, the Russian Federation and the United States account for 65% of the world's production of oilseed flax, and the demand for seeds of this crop is growing [1].

Flax oil has valuable nutritional and medicinal properties and has a positive effect on human health (in the prevention of cardiovascular diseases), it is also widely used in the oil paint industry. Flax can be considered the crop of the future since there is high demand flaxseed oil, rich in omega-3 fatty acids, and flaxseed products containing fiber [4, 5]. Mucilaginous substances from the surface of flax seeds have been identified as a valuable source of dietary fiber, which can be used to prevent stomach cancer. Therefore, many countries pay great attention to this culture as an indispensable product for Functional Nutrition [6-8]. Flax seeds are also used as an ingredient for bread baking and confectionery [9].

Modern flax varieties differ significantly from wild forms since genotypes with high yield, oil content, and resistance to biotic and abiotic factors were selected during the breeding process [3]. Conscious selection caused changes in the plant morphotype. Fiber flax forms have one long stem that does not branch, while oilseed flax has a much shorter, branched stem. The yield of seeds of oilseed flax varieties in high agriculture conditions is 0.3 - 0.5 t/ha higher than that of fiber flax.

With the beginning of synthetic breeding in agricultural production, the importance of the variety as a stable genetic system has increased, which has a complex of biological properties that ensure high yield and product quality under various growing conditions [9]. The intensification of agriculture makes it necessary to grow more agricultural products per unit area, which, accordingly, requires the creation of varieties more adapted to the conditions of the enhanced background of mineral fertilizers, the use of modern protective equipment, and innovative tillage technologies. It is also important to further improve oilseed flax using the latest breeding methods, taking into account the genetic characteristics of the parent components and their subsequent selection based on the ideotype of the variety.

Currently, research is primarily aimed at understanding the variability of agronomically valuable traits and their genetic polymorphism and at identifying the genotype by phenotype. Low breeding productivity is associated with the breeder's lack of a clear understanding of what characteristics should be used to select highly productive genotypes. In the existing selection triad "what to select?"(variety model), "how to select?" (breeding theory), and "from what to select?"(polymorphism) it is the first link that has been least studied [11].

To solve this problem, the breeder develops a whole system of traits that have a decisive impact on the productivity potential of a genotype created as a result of several breeding cycles [11]. The concept of a theoretically justified genotype called ideotype or variety model was founded by M. I. Vavilov for grain crops [12]. Even though with the fact that with the development of new scientific areas, such as genomics and bioinformatics, the development of the variety model has changed significantly, the classical concept has remained relevant. The concept of the term "variety model" has two aspects: as a synthesis of existing knowledge about the plant body and its response to changes in environmental conditions, or as a hypothetical ideotype that has an advantage over others [13]. Based on the knowledge of plant biology, the nature of inheritance of individual traits, it is necessary to involve in the breeding process genotypes that most effectively and positively respond to the cultivation technology created by the agronomist [10].

The largest areas under oilseed flax are located in the Steppe zone, where the main limiting factor for its yield is the amount of precipitation during the growing season. The fact that under conditions of sufficient moisture, the potential yield of flax increases is confirmed by research by scientists of the Institute of irrigated agriculture of the National Academy of Agrarian Sciences of Ukraine [14]. Given the trend of recent years to increase the aridity of Steppe regions due to climatic fluctuations [15] and the oversaturation of areas with sunflower and corn, it will be difficult to increase the yield of flax in the Steppe.

The Forest-Steppe zone, especially its central and northern regions, has an optimal water regime, shorter duration, and frequency of periods of strong and insufficient moisture during the growing season of plants, and therefore is favorable for growing oilseed flax. Also, in the conditions of the increasing amplitude of temperature fluctuations, there is a need to create new varieties of flax with high potential productivity.

Currently, domestic researchers from the Institute of Oil Crops of the National Academy of Agrarian Sciences have developed a parametric model of the oilseed flax variety for the steppe zone, which includes the researching of a significant amount of initial material, but such studies on flax breeding have not yet been conducted for the Forest-Steppe zone. Therefore, the creation of a new ideotype of the variety for the Forest-Steppe zone is no less an actual task [16].

The aim of the work was to develop an ideotype of oilseed flax variety adapted to Forest-Steppe conditions to accelerate breeding work, plan new breeding strategies, and create clear criteria for the breeding work.

Conditions and methods of conducting researches. The research was conducted during 2016-2019 in the conditions of breeding crop rotation in the village of Chabany of the Kyiv-Svyatoshinsky District of the Kyiv region. The climate of the Forest-Steppe zone of Ukraine is moderately continental.

The soil is middle sod-podzolic powdery sandy loam, the depth of the arable layer is 20-22 cm, the humus content is 1-1.6%, the pH of the salt solution is 5.4 - 6.0, the hydrolytic acidity is 2.1 - 2.4 mg - EQ. per 100 g of soil, the degree of saturation with bases is 55.3 - 58.0%. The content of nutrients in the soil is within the following limits: easily hydrolyzed nitrogen - 5.5 - 7.0 mg per 100 g of soil; mobile phosphorus - 12.3-13.6 mg per 100 g of soil; exchange potassium - 7.0-8.4 mg per 100 g of soil. So, the soil is slightly acidic, that is, suitable for growing oilseed flax. At the same time, the supply of soil with basic nutrients is sufficient. The predecessor of agro technical experiments in crop rotation was grain crops.

We studied the varieties: Evrika, Blakytno-Pomarachevyi, Oryginal, Sympatyk, which are included in the Register of plant varieties allowed for use in Ukraine, and 8 breeding lines of the nursery of competitive variety testing, according to the parameters of the yield structure, biochemical characteristics, height, lodging, and diseases resistance (table.1). The assessment of varieties was carried out according to the method of State Variety testing [17, 18]. The standard was the variety Pivdenna Nich. The oil content and protein content were determined by infrared spectroscopy on an Infratec (FOSS), the content of fatty acids was detected on an Agilent 7820 gas chromatograph (Alsi-Chrom). Statistical data processing was carried out using the Microsoft Office software package according to the method of B. A. Dospekhov [19].

Results of researches. Based on the obtained yield data of the best varieties of Ukrainian breeding, we create a model of the variety with a given genetic productivity potential for specific soil and climatic conditions. According to the results of field studies, the varieties of the NSC "Institute of Agriculture of the National Academy of Sciences" were characterized by the main economically valuable characteristics. Among the studied set of varieties, key indicators were identified for characteristics that directly affect yield and adaptability, based on which the ideotype of the variety for the Forest-Steppe zone is constructed (table 1).

1. Conditional ideotype of the oilseed flax variety for the forest-steppe zone, 2016 - 2018