The level of adaptability of perspective samples of soft and durum spring wheat in Ukrainian forest-steppe

In the Eastern Forest-Steppe zone of Ukraine, which is characterized by a sharp change in weather conditions during the growing season of agricultural crops, it is very important to grow hybrids that are most adapted to frequent weather anomalies during the growing season. This can significantly reduce their negative impact on the productivity of spring wheat. The results of a study of 20 samples (soft spring wheat Triticum aestivum L.) and (durum spring wheat Trīticum durum) of different ecological and geographical origin for adaptability when changing environmental conditions (Ukraine, Russia, Kazakhstan, Mexico, Sweden) are presented. Adaptability indicators were determined by the following characteristics: mass of one spike, mass of grain from one spike, number of grains from one spike, mass of 1000 seeds, mass of grain from 1 m. Samples that have high plasticity and stability by these characteristics have been identified. 3As a result of the conducted studies, the dependence between the main signs of productivity were established: the number of grains from one spike, the mass of grains from one spike, the mass of 1000 seeds, the mass of one spike, the mass of seeds from 1 m of Triticum aestium and Triticum durum samples. We have considered the adaptability of selection characteristics of samples by years with different environmental conditions: air temperature, relative humidity, precipitation amount, and hydrothermal coefficient.


Introduction
The issues related to the study of adaptability and plasticity of agricultural crops are becoming increasingly relevant. The Eastern Forest-Steppe zone of Ukraine is characterized by a sharp change in weather conditions during the growing season of agricultural crops. Therefore, it is important to grow agricultural crops that are most adapted to frequent weather anomalies during the growing season, which can significantly reduce the negative impact and meteorological conditions of spring wheat samples productivity. Studying of ecological plasticity and stability makes it possible to characterize the adaptive properties of an organism, to trace the dynamics of changes in the genotype reaction to changes in environmental conditions. Conducting such environmental studies allows us to identify the effect of abiotic and biotic factors of a certain environment on the genotype and determine the degree of their influence on the growth, development and yield of cropping, especially introduced samples that have a different reaction and yield potential. Accumulation of changes in the external environment is evinced in the variability of certain quantitative features of phenotype structure − morphological features of plant structure, yield, product quality, resistance to biotic and abiotic factors, which are determined by the initial form (Finley, 1963;Adamenko, 2007). The high sensitivity of individual samples to unfavorable growing conditions often narrows the area of their distribution to other ecological zones and limits their overall distribution.
The aim of our research was to assess the adaptability and ecological plasticity of soft spring wheat (Triticum aestivum L.) and durum wheat (Triticum durum Desf.)

Materials and Methods
Field research was conducted in 2018-2019 at the Educational Research and Production Center "Experimental Field of V.V. Dokuchaiev Kharkiv National Agrarian University (KhNAU named after V.V. Dokuchaiev). The experimental field is located within the land use of the educational and experimental farm of V.V. Dokuchaiev Kharkiv National Agrarian University in the northeastern part of Kharkiv region. 20 samples of the genus Triticum were used as the source material. In particular, Triticum section was represented by species Triticum aestivum L., section Dicoccoides Flaksb by species Triticum durum Desf (Table 1). The source material is obtained from the National the Center for Plant Genetic Resources of Ukraine and has a number of economically valuable features. Samples were introduced from different ecological and geographical areas. Sowing was carried out at the optimal time for the eastern part of the Forest-Steppe of Ukraine (April I-II), collection samples were sown manually under a marker, in rows of 1 m long each with row spacing of 0.15 m, at the rate of 100 grains per linear meter. All phenological observations were carried out in accordance with the guidelines for studying wheat collections (Zykin, 1984). Its predecessor is autumn fallow. The placement of land plots is standard. To assess the intraspecific and interspecific ecological variability of spring wheat, 30 plants of each studying sample were analyzed annually. To determine the adaptability of samples, we have calculated the average arithmetic values of the trait, maximum (max) and minimum (min) values, the coefficient of agronomic stability (As), the coefficient of variation (Vе), selection value (Sc), homeostasis (Hom) (Zhivotkov, 1997). The Levis stability coefficient (SF) was determined as SF = HE/LE, where NE and LE -the value of the trait for the maximum and minimum levels, respectively, n -an indicator of the experiments duration (Zhuchenko, 1980).

Results
During the research period (2018 -2019), weather conditions differed from the average many years' indicators in terms of temperature, precipitation, and their distribution in individual months. To estimate the environmental conditions for the soil formation and durum spring wheat productivity, the hydrothermal coefficient (HTC) was determined ( Fig.1) according to the method of G.T. Selyaninov (Snedekor, 1961).  Thus, in 2018 and 2019, the sowing-germination period (09.04-21.04) was characterized by dry conditions (HTC=0.3; 0.1, respectively). In 2018 stalk shooting phase took place in three periods of weather conditions and was characterized by arid and dry conditions (HTC=0.37, 0, 0.95, respectively). Accordingly, in 2019, this period was marked by dry conditions, excessive moisture and arid conditions (HTC=0. 07, 1.79, 0.19, respectively). The period of the beginning of tult formation in 2018 was characterized by dry conditions (HTC=0). In 2019, the period of milk-wax ripeness was dry (HTC=0), which did not contribute to the shaping and wheat grain formation. In general, during the study period, the humidity level was insufficient and was characterized in 2018, 2019 (HTC=0.47, 0.41). According to the method of A.V. Kilchevsky and L.V. Khotyliova (Goncharenko, 2005;Domashnev, 1992), the first stage of a comprehensive assessment of environmental parameters, phenotypic stability, and adaptive potential is disperse analysis to establish reliable differences between different effects (tables 2 and 3). The results of the conducted disperse analysis by the indicators of one spike mass, grain mass from one spike, number of grains from one spike, mass of 1000 seeds, grain mass from 1 m 2 confirm high reliable differences between the effects of genotypes of spring wheat samples (Tables 2 and 3). When assessing the influence of the studied factors (year, genotype) on the formation of productivity elements of various species of spring wheat, it was found that the greatest influence was: by the studied indicator, genotype had 72.41 % (mass of one spike); 93.1 % (mass of grain from one spike); 85.08 % (number of grains from one spike); 57.91 % (mass of 1000 seeds); 83.75% (mass of grain from 1 m 2 ) in soft wheat. Accordingly, in durum wheat, the influence of genotype was: 77.96 % (mass of one spike); 81.43 % (mass of grain from one spike); 71.12 % (number of grains from one spike); 73.08 % (mass of 1000 seeds); 93.05 % (mass of grain from 1 m 2 ). Analyzing the reaction of collection samples of spring wheat of various ecological and geographic origin, we have found that the average value of the mass of one spike in the experiment in soft wheat was 1.23 g, with a minimum (min) -0.83 g in the sample of Phyto 33/08 and maximum (max) -1.90 g in the sample of Sunnan (2018), accordingly in durum wheat -1.4 g, with a minimum (min) -0.85 g in Metyska sample and maximum (max) -2.14 g for variety of Orenburgskaya 21. In 2019 the average indicator for all samples was 1.10 g, at the minimum value -0.63 g in L 501 sample, maximum -1.60 g in Sunnan (soft wheat), and 1.44 g, 0.84 g (min) in Metyska sample, 2.14 g (max) in Nurla in durum wheat. Among the studied samples of the 2018-2019 collection, the best in terms of one spike mass (g) were Sunnan (1.75 g), Prokhorovka (135 g), Kharkivska 30 (1.27 g) and Simkodamyronivska (1.24 g), among awned samples -Phyto 14/08 (1.21 g)soft wheat; Orenburgskaya 21 (2.14 g), Nurly (1.69 g), Novatsiia (1.55 g) and Diana (1.51 g) -durum wheat (table 4).

The level of adaptability of perspective samples
Ukrainian Journal of Ecology, 10(6), 2020 By the range of variation (the difference between the maximum and minimum values of the feature), we can conclude about the degree of sample stability to the impact of changes in environmental conditions in the region: the lower this indicator, the more stable the sample is. The range of variability by mass of one spike in soft wheat was the highest in L 501 (0.68 g) and the smallest in Prokhorovka, Yrym, Phyto 14/08, Phyto 33/08 (0.01 g), which is reflected in terms of coefficients of indicator variations, 0.53, 0.63, 0.59 and 0.86 %, respectively. According to this indicator, the varieties were distributed in the following sequence: Prokhorovka, Phyto 14/08, Yrym and Phyto 33/08. Accordingly, in durum wheat Nurla was the highest range of variability by this indicator (0.91 g), the vast majority of samples had a low range of variability (0.01 g). The coefficient of variation for the collection varied between 0.33-38.2 %. Samples that reacted to the improvement of conditions in susceptible years and insignificantly in limited conditions can serve as a source material for increasing plant productivity in the Forest-Steppe of Ukraine. Among the studied samples, the greatest fluctuations by the mass of one spike (coefficient of variation V ≥ 20 %) had L 501 (V=49.5 %) -in soft wheat and Nurla sample (V=38.19 %)in durum wheat. Stability coefficient from the agronomic point of view (As) characterizes the economic value of the source material: according to it, variety samples with a stability coefficient exceeding 70% are most valuable for production. According to this criterion, the presented variety samples of soft wheat belong to stable ones, except for L 501 (As=50.4 %), respectively in durum wheat Nurla sample is not stable (As=61.81 %). Assessment of the best collection samples of soft spring wheat for homeostaticity, that is, the ability of the genotype to minimize the effects of unfavourable environmental conditions in different periods of plant growth and development, gives grounds to assert that the most homeostatic (stable) by mass of one spike were samples: Prokhorovka, Phyto 14/08 and Yrym, which had the highest levels of homeostaticity (Hom1=255.8, 205.4 and 175.8, respectively) and agronomic stability (As=99.5 %, 99.4 % and 99.4 %). Accordingly, in durum wheat among the studied collection, the best samples were: Orenburgskaya 21, Novatsiia, Diana, which had the highest levels of homeostaticity (Hom 1=644.6, 337.6 and 320.3, respectively) and agronomic stability (As=99.7 %, 99.5 % and 99.5 %). The above-mentioned samples most stably realized their potential under changing growing conditions. The least stable among the studied variety samples was L 501 (Hom1=1.96; As=50.4 %), in soft wheat and Zolotko sample (Hom1=6.93; As=79.8 %) -in durum wheat. A similar regularity was observed by the Hom2 indicator.
The selection value index (Sc) allowed us to distinguish samples that combine the high or medium mass of a single spike and its stable realization under changing growing conditions, which is most important in production. Among the studied samples, the highest indicators of selection value had: Sunnan (Sc=1.47), Prokhorovka (Sc=1.34), Kharkivska 30 (Sc=1.23) and Phyto 14/08 (Sc=1.20) -in soft wheat and samples of Nurla (Sc=2.93), Orenburgskaya 21 (Sc=2.13), Novatsiia (Sc=1.54) and Diana (Sc=1.50)in durum wheat. The sample of soft wheat L 501 was significantly inferior to other studied samples in terms of selection value (Sc=0.47), in durum wheat -a sample of Metyska (Sc=0.84), respectively. A sample is considered stable by manifestation of productivity characteristics if their stability coefficient is close to unity. In our studies, the following samples of soft wheat were more stable in terms of the mass indicator of one spike: Prokhorovka, in which the Levis phenotypic stability coefficient was 1.01, Yrym (SF=1.01), Phyto 14/08 (SF=1.01), Phyto 33/08 (SF=1.01); durum wheat -Orenburgskaya 21 (SF=1.00), Slavuta (SF=1.01), Bucuria (SF=1.01), Altyn Shygys (SF=1.01) and others (table 4). Samples Kharkivska 30 and L 685-12 were slightly less stable by the studied indicator: respectively, the stability coefficients were 1.03 and 1.04 (soft wheat), in durum wheat of sample Zolotko (1.03). The data are coordinated with the agronomic stability coefficient (As). The level of adaptability of perspective samples Ukrainian Journal of Ecology, 10(6), 2020 0.44-44.09 %. Among the studied samples, the greatest fluctuations by the indicator (coefficient of variation V ≥ 20 %) had: L 501 (V=53.43 %) -in soft wheat and Nurla sample (V=44.09 %) -in durum wheat. Analysis of the stability coefficient showed that the presented varieties sample of soft wheat according to this criterion belong to stable, except for L 501(As=46.57 %), respectively, in durum wheat, Nurla sample is not stable (As=55.91 %). Assessment of the best collection samples of soft spring wheat for homeostaticity, gives grounds to assert that the most homeostatic (stable) by grain mass from one spike were samples: Prokhorovka, Sunnan and Kharkivska 30. Accordingly, their homeostaticity indicator was (Hom1= 148.6; 73.1 and 46.7, respectively), and agronomic stability (As = 99.3 %, 98.3 % and 97.9 %). In durum wheat, the best samples were: Orenburskaya 21, Novatsiia, Kustanayska 30, which had the level of homeostaticity Hom1= 373.4; 96.8 and 76.4, respectively, and agronomic stability As=99.6 %; 98.8 % and 99.0 %. These samples most stably realized their potential under changing growing conditions. The least stable among the studied variety samples were L 501 (Hom1 = 1.26, As = 46.6 %), in soft wheat and Nurla sample (Hom1 = 2.8, As = 55.9 %) -in durum wheat. A similar regularity was observed by the Hom2 indicator.   (table 6). The range of variability by the studied indicator in soft wheat was the highest in Sunnan (1.8 pieces) and the smallest in CIGM.250 (0,8 pieces), Yrym (1,0 pieces), Phyto 33/08 (1.0 pieces), L 685-12 (1.0 pieces). Accordingly, the coefficients of variation were 3.8, 4.2, 4.2 and 4.3 %. According to this indicator, the samples were distributed in the following sequence: -CIGM.250-, Phyto 33/08, Yrym and L 685-12. The range of variability in durum wheat was the highest in the sample of Nurla (3.0 pieces), the lowest indicators were shown by samples:  The indicator of selection value (Sc) allowed us to identify samples that realize high productivity, namely: Analyzing the reaction of collection samples of spring wheat of various ecological and geographic origin, we have found that the average value of 1000 seeds mass in the experiment in soft wheat was -34.5 g, with a minimum (min) -28.3 g in the sample of Phyto 14/08 and a maximum (max) -45.0 g in the sample of Sunnan (2018), respectively in durum wheat -37.7 g, with a minimum (min) -24.6 g in the sample of Zolotko and maximum (max) -58.6 g for Novatsiia sample. In 2019 the indicator was 39.8 g, at the minimum value -28.1 in Prokhorovka sample (RUS), the maximum -55.7 in Yrym (KAZ) (soft wheat), and 34.8 g, 25.5 g (min) in Kustanayskaya 30 sample, 44.7 g (max) in Novatsiia, durum wheat. Among the studied samples of the collection during 2018-2019, we can distinguish the best samples in terms of 1000 seeds mass (g): Sunnan (49.10 g), Yrym (47.20 g), Simkodamironovska (39.90 g) and Kharkivska 30 (39.4 g) -soft wheat; Novatsiia (51.6 g), Orenburgskaya (49.2 g), Altyn Shygys (37.3 g) and Diana (36.8 g) -durum wheat (table 7). The most stable samples to changes in environmental conditions were samples from soft wheat: Yrym (17.0 g), studying of the mass indicator of 1000 seeds showed that less stable and at the same time dependent on changes of growing conditions were: L 685-12 (0.80 g), CIGM.250-(1.4 g), Phyto 33/08 (3.0 g), Simkodamironovska (5.2 g), the obtained data are confirmed by the coefficient of variation: respectively, in soft wheat it was: 1.81, 3.32, 6.16 and 9.22 %, and in durum wheat Novatsiia (13.90 g). According to this indicator, the samples were distributed in the following sequence: L 685-12, CIGM.250-, Phyto 33/08, Simkodamironivska. Accordingly, the range of variability by this indicator in durum wheat was the highest in Novatsiia (13.90 g), the vast majority of samples had a low range of variability. The coefficient of variation for the collection varied between 0.67 -13.90 %. The largest fluctuations in the mass of 1000 seeds (coefficient of variation V ≥ 20 %) among the studied samples had Kharkivska 30 (V = 29.12 %) -in soft wheat and Novatsiia sample (V = 19.03 %) -in durum wheat. When describing the economic value of the source material, it is worth noting samples in which the stability coefficient exceeds 70 %. All presented collection samples of spring wheat are considered stable by this criterion. soft wheat and samples of Altyn Shygys (Sc = 41.7), Novatsiia (Sc = 39.4), Orenburgskaya 21 (Sc=38.5) and Diana (Sc = 37.4) -in durum wheat. Soft wheat samples were the most stable in terms of the mass indicator of 1000 seeds: CIGM.250 (SF = 1.1), Phyto 33/08 (SF = 0.9), L 685-12 (SF = 1.0); in durum wheat -Slavuta (SF = 1.0), Diana (SF = 1.0), Bucuria (SF = 1.0) and others (Gable 7). Analyzing the reaction, collection samples of spring wheat showed a different reaction in terms of seed mass from 1 m 2 on average, according to the experiment, soft wheat had an indicator of 309.2 g, with a minimum (min) -184.5 g for Phyto 33/08 sample and a maximum (max) -548.8 g for L 501 variety (2018), respectively, for durum wheat -200.5 g, with a minimum (min) -87.0 g for Metyska sample (UKR) and maximum (max) -352.1 g for Kustanayskaya 30 variety. In 2019 on average, for all samples, the indicator was 277.1 g, with the minimum value -150.6 in Phyto 33/08 sample (UKR), the maximum -411.0 in L 501 (soft wheat), and 189.4 g, 112.4 g (min) in Metyska sample, 290.5 g (max) in Kustanayskaya 30 in durum wheat. Among the studied samples of the 2018-2019 collection, the best in terms of seed mass from 1 m 2 (g) were L 501 (479.9 g), Simkodamironovskaya (455.9 g), Prokhorovka (299.5 g) and Kharkivska 30 (295.5 g) -soft wheat; Kustanayskaya 30 321.3 g, Orenburgskaya 21 269.4 g, Novatsiia 243.4 g and Nurly 199.2 g -durum wheat (Table 8). In terms of the range of variation in soft wheat, it was the highest in L 501 (137.9 g) and the lowest in L 685-12 (8.0), Prokhorovka (21.7), Yrym (29.0), Phyto 33/08 (33.9 g), which is reflected in the coefficients of variation of the indicator, 3.06, 5.1, 7.7 and 14.3 %, respectively. The range of variability according to this indicator in durum wheat was the highest in Kustanayskaya 30 (61.6 g), slightly less had the following samples: Diana (3.2 g), Slavuta (5.1 g), Altyn Shygys (12.9 g). The coefficient of variation for the collection varied between 1.57 and 18.0 %. Among the studied samples, the largest fluctuations in the mass of seeds from 1 m 2 per spike (coefficient of variation V ≥ 20 %) L 501 (V = 20.3 %) -in soft wheat and Metyska sample (V = 18.0 %) -in durum wheat. According to the stability coefficient, which (As) characterizes the economic value of the source material all presented wheat varieties samples belong to stable, so As > 70 %. Assessment of collection samples for homeostaticity showed that the most homeostatic (stable) by seed mass from 1 m 2 were the following samples: L 685-12, Prokhorovka and Yrym, (Hom1 = 6027.3, 5828.4 and 3463.4) and agronomic stability (As = 96.9, 94.9 and 92.3 %). Accordingly, in durum wheat, the best samples were Diana, Slavuta, Novatsiia (Hom1 = 9291.4, 9171.7 and 5452.6, respectively) and agronomic stability (As = 98.4, 98.0 and 95.5 %). The above-mentioned samples most stably realized their potential under changing conditions. Phyto 33/08 was the least stable among the studied samples (Hom 1 = 1171.8; As = 85.7 %), in soft wheat and Metyska sample (Hom1=552.9; as=81.96 %) -in durum wheat. Among the studied samples, the highest indicators of selection value (Sc) had the following samples: L 501

Conclusion
According to the high level of homeostasis and selection value, the samples Kharkivska 30, Simkodamironivska, Sunnan and Prokhorovka were identified among the studied varieties, which are valuable source material for spring wheat selection according to these indicators. It was determined that samples of foreign selection were mainly inferior to samples of domestic selection both by yield level and its stability, which is caused by their less adaptability to growing conditions. We determined that Prokhorovka, Kharkivska 30, Simkodamironivska (spring soft wheat) and Zolotko, Slavuta, Bucuria (spring durum wheat) have a high selection value, while Prokhorovka and Yrym (spring soft wheat) and Orenburgskaya 21 (spring durum wheat) have a high homeostasis in their genotype under unfavorable conditions. These samples can be recommended for use in selection practice to obtain the high-yielding varieties with high adaptive ability to growing conditions.