Introduction of breeding samples of meadow clover according to economically valuable characteristics using modern breeding methods

. The paper presents the results of research on the formation of complex hybrid populations, an assessment of the collection samples of clover on a complex of economically valuable traits for the creation of forage varieties. The basis for the study were promising plants that weresown in a wide row and individually in a row. By negative selection, weak and underdeveloped plants were mowed down. It`s been noticed that there was the direct dependence of clover seeds` creation from the weather conditions. The collection samples of meadow clover`s assessment was given according to the complex of economically valuable features for the creation of the hay – pasture type varieties. The best samples are allocated for the yield of the green mass, the plants` height. The initial material was obtained on the signs of adaptability, yield of green mass, foliage and seed productivity. Promising clover samples were selected for high seed productivity, reaching more than 60 %. Similarly, in accordance with the vertical zonality of the natural habitats of wild introducers, the protein content in plant samples also increases. In terms of fodder yield, the maximum indicators were noted in the varieties Farn, Ustodlivy (Belorussian selection), Orlik (All-Russian Scientific Research Institute of Legumes and Millet Crops), complex hybrid populations that exceeded the standard – the Daryal variety by 12-25%. According to seed, Nart varieties were distinguished. Synthetic populations Syn 305-03, Syn 274-94 (selection SKNIIGPSH VNC RAS), FM-143(VNII kordov), Dargavsky, (wild specimen of RSO – Alanya).


Introduction
Modern technologies for the cultivation of crops are focused on a combination of highlyefficient agrotechnical measures that ensure the creation of the necessary conditions for the growth and development of plants, maximum productivity of photosynthesis, obtaining the planned harvest of high quality [1,2,3].Increasing the production of competitive agricultural products is of paramount importance for the Russian economy.In solving this problem, a certain role belongs to fodder production.Improving the sown areas of perennial grasses is the main link in solving the producing high-quality feed's problem.One of the valuable sources of feed protein is legume grasses.In recent years, in the conditions of the RSO-Alania, there has been a significant decline in the production of seeds of perennial grasses, which negatively affects not only feed production, but also other branches of agricultural production.Despite the important national economic worth, the actual production of seeds of perennial legume grasses remains at a low level.[4,5,6].
In the case of restoration biodiversity of phytocenoses, improving hayfields and pastures, the reproduction of land fertility, the introduction of wild species, their studying, the selection of the best genotypes and on their basis the creation of new varieties adapted to specific regions is of great importance.[7,8,9].
On the introduction basis of the researching species, the selection methods and carrying useful plants from one condition of existence to another are studied.By the way, there` s a knowledge of the laws of plant organisms with the development of methods and using it in national economy.Particularly important indicators of varieties of the hay-pasture type are their adaptation, high competitiveness and seeding of inflorescences [10].
The selection of such plants in one nursery of complex hybrid and synthetic populations is an effective breeding method based on the use on the effect of multiple heterocysis.This method is widening in the breeding of perennial grasses such as clover, alfalfa and others [11][12][13][14].

Methodology
To create competitive clover varieties, selection samples were evaluated at altitudes of 600, 900, 1200,1600 and 2000m a.s.l.Wild forms selected in natural conditions were studied in a collection nursery, complex hybrid populations formed from wild samples of the mountain zone.Laying of nurseries, field observations, assessment of morphological guidelines.As a standard, a zoned variety of meadow clover -Daryal -was used.The area of the plot was 15-20 m2.
At the V.R. Willams Research Institute of feed, DNA marker analysis of clover samples for the presence of longevity trait genes was carried out using 5 pairs of microsatellite primers (SSR) (S.Santo, S. Isobe, E. asamizu, N. Ohmido, K. Okumara, I. Klimenko, S.

The results of the research
Zoned varieties of meadow clover Daryal (standard), Alan and Nart in the second and third year of life reduced the number of stems and thereby weakly withstood the competition of cereal and multi-grass components.Their adaptation in the mixture is 30-35%.More than 50% of the competitive ability was shown by wild forms from high-altitude areas and the Farn variety, formed from wild plants (Table 1).Wild specimens from mountainous regions that are part of synthetic populations were distinguished by good food advantages.The legend of their stems in the stem phase was 5-7 c, lower than that of cultivated varieties.However, during the flowering period in mixed crops, the level of other varieties was reached.They also had advantages on the basis of foliage (2-6 % higher than the rest of the studied samples).The degree of foliage (58-69 %) was higher in samples introduced from areas of vertical zonality with the greatest excess above sea level.Similarly, in accordance with the vertical zonality of the natural habitats of wild introducers, the protein content in plant samples also increases.In terms Farn, Ustodlivy (Belorusian selection), Orlik (All -Russian Research Institute of Legumes and Millet Crops), complex hybrid populations that exceeded the standard -the Daryal variety by 12-25 %.In seed productivity, Nart varieties were distinguished.Synthetic populations Syn 305-03, Syn 274-94 (selection SKNIIGPSKh VNC RAS), FM-143 (VNII kordov), Dargavsky.For the purpose of attraction the initial images, the selection included wild samples taken in the mountain conditions of natural phytocenoses, where the seed productivity of each selected plant was more than 50%, and the seed yield reached more than 0.4 kg per m 2 (Table 2).In the variety of Raznotravny-zlakovy travostoi of natural phytocenoses the plants have much more higher rates of seeding and when introduced in collection nurseries, their yield reaches 352-407 g/m 2 , which is significantly higher than that of the plants selected in legume-cereal herbage stands at a specific altitude above sea level.Biochemical analysis of wild introduced samples showed a high protein content and low fiber content in the early flowering phase (25% and 15%, respectively).Plants of wild forms contained phosphorus E3S Web of Conferences 431, 01013 (2023) ITSE-2023 https://doi.org/10.1051/e3sconf/2023431010130,6-0,8%, sugar 2-4%, ash 8-10%, which slightly exceeds the quality indicators of breeding samples grown at an altitude of 600 m above sea level.The incidence of the most common diseases in the region (anthracnose, ascochitosis, brown spotting) did not reach 1,5-1,8 points, while other samples were affected in the range of 3,5-4 points.Comparative evaluation of aboriginal populations, cultivated varieties, formed complex hybrid populations at different altitudes, made it possible to establish the influence of the environment on seed knotting.Based on the studies conducted, it was determined that with the rise in mountain height, wild plants, in contrast to cultivated varieties, had a higher percentage of seeds formed than in the collection nursery, according to a complex of signs, promising samples for the formation of meadow varieties are allocated.These are cultural varieties: Minsk Mutant, Orlik, Memory of Lisitsyn, Yaskrava, Farn; wild specimens from mountain regions: Dargavs, Gornaya Saniba, Vakats,complex hybrid populations.Syn 305-03, Syn 300-99, Tos-31, FM-46, Syn 320-08,321-08 (Table 3).genetic level with the Tetraploid VIC and Veteran varieties when using 3 pairs microsatellite primers (RCS 00117R/F; RCS 130R/F and RCS 3711/F) (fig.1).Given that the tetraploid VIC and Veteran varieties have established themselves on the basis of long-term observations as being distinguished by high winter hardiness-up to 90%, resistance to clover cancer and high longevity, we can consider the Wild-growing sample promising in breeding of long-term and stable variety.
The initial breeding material of clover in terms of fodder and seed productivity for the formation of new varieties of fodder direction has been allocated.
Having used the method of DNA marker analysis using SSR primers, it was revealed that the wild-growing sample has similarities at the genetic level with the varieties Ttraploid VIC and Veteran.Considering that these varieties have proven themselves based on the results of long-term observations, as distinguished by high winter hardiness-up to 90%, resistance to clover cancer and high longevity, it is possible to consider a wildgrowing sample promising in breeding of long term and stable variety.

Conclusions
Complex hybrid populations have been obtained.An assessment of collection samples of clover by a complex of economically valuable features for the creation of varieties of haypasture type is given.The best samples for the yield of green mass, bushiness, plant height are highlighted.The starting material was obtained on the signs of adaptability,yield of green mass, foliage and seed productivity.Promising samples of clover were selected for high seed productivity, reaching more than 60%.On the basis of markers of oriented selection, complex hybrid populations have been formed for further selection work.

Table 2 .
Evaluation of wild clover plants in various conditions of mountain phytocenoses

Table 3 .
Morpho-biological signs of breeding samples of clover (on average for 2019-2021)