Main Spike Research Articles

EFFICIENCY OF SUPRAMOLECULAR COMPLEXES OF TEBUCONAZOLE WITH PLANT METABOLITES AT CULTIVATION OF SPRING WHEAT

The work presents the results of the research into field efficiency of application of new fungicides when growing spring common wheat in the foreststeppe zone of Western Siberia. At the beginning of the earing phase, crops of spring common wheat Novosibirskaya 31 and Obskaya 2 were treated with fungicides on the basis of tebuconazole in the form of its supramolecular complexes with vegetable metabolites - licorice root extract {Glycyrrhiza uralensis) and polysaccharide arabinogalactan from Larex sibirica and Larix gmelinii. The use of tebuconazole complexes with licorice extract and arabinogalactan suppressed the development of major leaf diseases - Septoria, brown rust and powdery mildew. In spring wheat crops of Novosibirskaya 31, the development of diseases decreased by 95.4- 100%, which is comparable with the biological efficiency of commercial fungicide Folicur, CE - 97.1-98.1%. Spraying of Obskaya 2 crops with the studied preparation led to the decrease in the prevalence of Septoria disease by 92.1-97,0%, and the use of Folikur - by 97.1%. The treatment with fungicidal complexes increased the assimilation surface of the flag leaf in both spring wheat varieties. The complex of tebuconazole with licorice extract proved to be the most efficient: in Novosibirskaya 31 the area of the flag leaf increased by 27%, in Obskaya 2 - by 29.8%. When using tebuconazole with arabinogalactan, the flag-leaf area increased by 24 and 22%, respectively. Spraying crops with Folicur increased the performance of the varieties Novosibirskaya 31 by 25.6%, Obskaya 2 - by 24.5%. The weight of grains of the main spike also increased in the variants of treatment of Novosibirskaya 31 with tebuconazole complex with licorice extract by 36.1%, and with arabinogalactan - by 34.4%, which was higher than during crop treatment with Folicur (33.7%). The increase in the grain weight of the main spike of Obskaya 2 wheat variety was 18.4% and 13.8%, respectively, depending on the preparation, while Folikur's application provided the increase by 11.6%. Spraying crops with the studied preparations ensured the increase in the yield of spring wheat grain of the variety Novosibirskaya 31 by 12.1-12.3%, which is comparable with the results of using Folicur - 11.9%. The responsiveness of the variety Obskaya 2 on the application of the complex of tebuconazole with licorice extract was higher and accounted for 20.1%, when spraying tebuconazole with arabinogalactan, its yield increased by 11.2%, and the use of Folicurum led to the increase by 6.6%. Thus, in the conditions of the forest-steppe of Western Siberia, it is more efficient to treat spring common wheat crops at the beginning of the wheat earing phase with the composition of tebuconazole with licorice extract in the consumption rate of the preparation 0.5 kg/ha.

Combining ability analysis for yield and its components in bread wheat (Triticum aestivum L.)

Combining ability was analyzed using a line × tester (8 × 4) analysis in bread wheat (Triticum aestivum L.). Combining ability analysis, revealed the importance of both additive as well as non-additive genetic variances for control of various traits. The potence ratio (σ2gca/ σ2sca) suggested the preponderance of additive gene actions for number of effective tillers per plant, length of main spike, number of spikelets per main spike, number of grains per main spike and 100-grain weight and non-additive gene actions for rest of the traits. Parent MP 3288 was the best general combiner, whereas crosses MP 3288 × GW 496 and MP 3288 × GW 366 were found to be the best specific combiners for grain yield per plant and some of the yield contributing traits. However, on the basis of per se performance and significant SCA effects for grain yield per plant and some of its important components, hybrids MP 3288 x GW 366, MP 3288 x HI 1544 and GW 173 x GW 451 were considered to be the most promising for further exploitation in breeding programmes.

Evaluation of Quantitative Transgression Traits of Spring Barley Hybrids

The evaluation results of the degree and frequency of transgression and the degree of phenotypic dominance of spring barley (Hordeum) hybrids F2 by productivity elements as a result of saturating crosses are presented. Studies were conducted in the Laboratory of Cereal Crops Breeding in Primorsky Research Institute of Agriculture from 2011 until 2017. Based on the analysis of the morphogenetic process in hybrid populations F2 of spring barley, it was established that plant productivity in multirow forms is determined by the productive tillering and the grain content in the spike. As a result, transgressive F2 hybrid combinations of spring barley were distinguished by the main elements of productivity. The highest degree of transgression (Td) was noted for productive tillering in the combination (Vostochny × Omsky 85) × Omsky 85 (120.0%), the number of grains from the main spike was observed in the combination (Primorsky 44 × Ken Pi 2) × Ken Pi 2 (29.6%), and the seed weight per plant was observed in the combination (Primorsky 89 × 03N5) × 03N5 (138.4%).

The influence of mutagenic factors on agronomic traits of spring barley varieties in М1 and emergence of modified forms in М2

Purpose. To determine response of spring barley varieties to action of different concentrations of mutagens in M1. To study effect of the mutagens on the formation of agronomic traits in M1, M2 spring barley varieties. Methods. The experiments with the varieties of Myronivka breeding Virazh and Talisman Myronivskyi were carried out in 2016, 2017 in the conditions of the experimental field of the Scientific-Research Center of Bila Tserkva National Agrarian University as well as in laboratory. The seeds were soaked in solutions of mutagen hydroxylamine (HA) at concentrations 1.0 % (high); 0.5 % (medium), and 0.1 % (low) and mutagen nitrosomethylurea (NMU) at concentrations 0.1 % (high), 0.01 % (medium) and 0.001 % (low). Seeds soaked in water were as the control. The exposition was 18 hours. In M1 seed vigor in laboratory conditions and field germination were evaluated. In M2 plant height, main spike length, grain number and grain weight per main spike were determined. Seeds harvested from the control variants in M1 were used as the control in M2. Results. As compared with HA the mutagen NMU at high-concentration caused high level of depression in spring barley seedlings resulted in decrease of field germination for the variety Vіrazh to 24.0 %, for the variety Talisman Myronivskyi to 51.0 %. When treating seeds with NMU at high concentration, in M1 of the variety Vіrаzh the plants with loose and long (12.7 cm) spike were obtained, whereas 10.0 cm in control. In М2 the variety Vіrazh families were obtained (10/4, 11/2б and 11/4) with significant decrease in plant height (53.0–53.3 cm, control 60.2 cm) which were obtained by the action of mutagen NMU at medium and low concentrations. When mutagen HA in low concentration and mutagen HMM in high concentration acting on seeds of the variety Vіrazh, families (5/1 and 9/2) were obtained which significantly exceeded control in main spike length and grains number per main spike. Conclusions. The indices seed vigor, field germination and main spike length were the most informative ones for mutagenic action in spring barley M1. The action of mutagen NMU in high concentrations caused higher level of depression than mutagen HA. Seed germination was influenced by mutagen concentration, mutagen nature and genotype. In M2 of the varieties Virazh and Talisman Myronivskyi the appearance of modified forms in terms of plant height, main spike length, grain number and grain weight per main spike have been marked. The best results were achieved by the action of high concentration of NMU and high and low concentration of HA The genotype, mutagen concentration and the nature of the mutagen influenced on the formation of yield components in M2. Studies on mutant generations will continue in M3 and M4 to search valuable mutations.

Multi-Locus Genome-Wide Association Studies for 14 Main Agronomic Traits in Barley.

The agronomic traits, including morphological and yield component traits, are important in barley breeding programs. In order to reveal the genetic foundation of agronomic traits of interest, in this study 122 doubled haploid lines from a cross between cultivars “Huaai 11” (six-rowed and dwarf) and “Huadamai 6” (two-rowed) were genotyped by 9680 SNPs and phenotyped 14 agronomic traits in 3 years, and the two datasets were used to conduct multi-locus genome-wide association studies. As a result, 913 quantitative trait nucleotides (QTNs) were identified by five multi-locus GWAS methods to be associated with the above 14 traits and their best linear unbiased predictions. Among these QTNs and their adjacent genes, 39 QTNs (or QTN clusters) were repeatedly detected in various environments and methods, and 10 candidate genes were identified from gene annotation. Nineteen QTNs and two genes (sdw1/denso and Vrs1) were previously reported, and eight candidate genes need to be further validated. The Vrs1 gene, controlling the number of rows in the spike, was found to be associated with spikelet number of main spike, spikelet number per plant, grain number per plant, grain number per spike, and 1,000 grain weight in multiple environments and by multi-locus GWAS methods. Therefore, the above results evidenced the feasibility and reliability of genome-wide association studies in doubled haploid population, and the QTNs and their candidate genes detected in this study are useful for marker-assisted selection breeding, gene cloning, and functional identification in barley.

An ECG simulator with a novel ECG profile for physiological signals

This work introduces a low-cost open-source electrocardiography (ECG) simulator comprising both MATLAB software for signal generation and a dedicated circuit board for signal output via a commercial sound card. Synthetic, rate-dependent ECG simulation is based on third-order polynomials that are calculated in sections for the main waves and spikes, respectively. Besides the heart rate, the output profile is fully adjustable with respect to Einthoven lead signals I–III, the amplitudes of the individual ECG waves and spikes, as well as the constitution and intensity of common distortions. The underlying coefficients for the synthetic ECG profile are obtained experimentally by analysing recordings of 22 healthy individuals with heart rates in the range of 40–180 bpm. Eight of these recordings are selected to determine the coefficients for the polynomials (training set) while the remaining 14 serve as test set to evaluate their applicability and accuracy. Thereby, a mean correlation of 98.57% is found which is superior in comparison with a widely accepted rate-dependent ECG profile that is generated from square root and linear terms (correlation score: 91.46%). Although other use-cases are feasible, the focus of this work is the development of an ECG simulator for academic research and university education. Both the MATLAB source code and the circuit layout files are available in the online supplement stimulating further work on this topic.

Research on influence of environment factors to yield and quality traits of Perilla frutescen

The research is aimed to study of the influence of environmental factors on the yield and quality traits, and find out the regularity of the growth and development of perilla. The main environmental factor data in six ecological area in Guizhou province were collected, and the correlation analysis with yield and quality traits of 15 perilla strains was conducted. The results showed that the cultivation environment has significant effects on the yield and quality traits of perilla. The effect of environment on main yield composed traits, contained grain number in top spike, effective panicle number per plant, plant height, top spike length, growth period, and thousand seed weight was degressive. In the different environmental factors, the latitude showed positive correlation with yield, growth period and effective panicle number per plant, and negative correlation with top spike length and grain number in top spike. Elevation showed negative correlation with the growth period of perilla. The perilla yield increased at first and then decreased with altitude rising, with the maximum in the 800 m altitude. The 600-900 m altitude is suitable area for perilla. Except for positive correlation with the plant height, and negative correlation with top spike length, the longitude showed in apparent impact on other traits. Sunshine duration, temperature and rainfall accumulation showed different effect on the different perilla strains. For yield composed traits, the sunshine duration was negatively correlation with the plant length. The accumulated temperature and mean temperature showed negative correlation with the main spike length, the rainfall showed negative correlation with the precipitation and growth period, plant height, ear number. The environmental impact on the oil compounds decreased with oleic acid, stearic acid, linoleic acid, α-linolenic acid, palmitic acid and oil content. Correlation analysis showed that the significantly negative correlation between the oil content and palmitic acid and linoleic acid content, and the positive correlation between linolenic acid content, α-linolenic acid content showed significant negative correlation with other fatty acids composition, and palmitic acid, stearic acid, oleic acid, linoleic acid showed significant positive correlation with each other. The influence of different environmental factors on the quality of perilla were as follows: the oil content was positively associated with elevation and sunshine duration. α-Linolenic acid content showed negative correlation with longitude, latitude, accumulated temperature and mean temperature, but positive correlation with altitude, sunlight and rainfall capacity. The correlation between palmitic acid, stearic acid, oleic acid, linoleic acid and environmental factors showed contrast character of α-linolenic acid. This study detailed discussed the influence of environmental factors on the quality of perilla, which provided the foundation of ecological planting technology and geoherbalism research of perilla.

Effect of predicted climate change on growth and yield performance of wheat under varied nitrogen and zinc supply

Sustainable crop production is crucial to address global food security and requires a solid input of chemical fertilizers containing macro (e.g. nitrogen: N) and micro (e.g. zinc: Zn) nutrients. However, climatic factors beyond farmers’ management capabilities determine the final crop yields, and world’s climate has been changing more rapidly than ever due to human activities such as industrialization and deforestation. This study evaluates the interactive effects of predicted climate change and N and Zn supply on performance of bread wheat as a model staple food crop. Bread wheat (T. aestivum cv. Ceyhan-99) was cultivated in soil fertilized with adequate or low N and Zn in pots under ambient climate (ambient CO2 and temperature) or predicted climate (700 μmol mol−1 CO2 and 3 °C temperature rise) conditions in dedicated plant growth chambers. Plants were harvested at full maturity and grain yield, and yield attributes along with Zn and N status of grains were determined. Predicted climate (PC) treatment significantly accelerated plant growth rate resulting in early onset of successive growth stages and maturity. In both PC and ambient climate (AC) conditions, adequate supply of N and Zn significantly increased straw and grain yield by increasing number of spikes per plant and number of grains per spike, whereas PC significantly reduced straw and grain yield through reducing number of spikes per plant, particularly in plants supplied with adequate N. Effect of adequate Zn or PC treatments were significant only under adequate N supply. Adequate N not only increased grain protein concentration but also grain Zn, particularly under adequate Zn application. In general, PC tended to increase grain Zn concentration, but the effect was non-significant. PC had no effect on grain protein concentration, whereas it significantly reduced grain protein yield (i.e. total mass of protein in whole grains of a single plant). The future climate with elevated CO2 and raised temperature can dramatically reduce duration of time to complete successive growth stages in wheat. Plants cultured under PC conditions had significantly lower straw and grain yield, although supplied with ample fertilization. Whereas the PC and adequate Zn treatments enhanced main spike gain yield and number of grains per spike, PC declined overall grain yield, particularly due to severe reduction in number of spikes per plant. We conclude that sustaining a higher number of spikes per plant along with adequate nutrition with N and Zn are key factors to benefit from an elevated CO2 atmosphere and to minimize adverse effects of rising temperatures on wheat yield and quality.

Contribution of main culm and tillers to grain yield of durum wheat: Influence of sowing date and plant traits

The question of whether tillers are a burden or a resource in durum wheat is of concern in the variable Mediterranean climates. The contribution of tillers to grain yield was investigated in commercial cultivars differing in time to anthesis, tillering and spike size, in response to three sowing dates:mid-autumn (recommended), winter, and early spring. The thermal time of phenological phases was calculated, and yield-components and floret production were analysed separately in main culm and tillers. Tiller spikes showed higher spikelet abortion coupled to lower spikelet fertility and mean kernel weight, so that grain yield was 40-60% lower than in main culm spikes. Despite this, tillers contributed 35 to 50% to plant yield. The sowing date affected tiller number rather than one tiller yield. In winter sowings (December), lower main culm yield was fully compensated by increased tiller yield, whereas shifts of sowing date to early spring (February) reduced tillering, which caused a yield loss ranging from 12 to 20%. Cultivars differed in one tiller yield rather than in tiller number, and higher grain yield of tillers was primarily due to increased grain recovery. A more equal partitioning of resources within main culm and tillers corresponded to better yield stability across sowing dates. Starting from this, we suggest that early anthesis, a long stem elongation phase, a high primordium initiation-rate and small spikes, could be positive traits for durum wheat yield stability in changing environments, since they allow plants directing more time and resources to floret production and grain filling both in main culm and tiller spikes. From a methodological point of view, our results show that the number of fertile florets per spike is highly correlated with the average floret number of five given spikelets.

ОСОБЕННОСТИ ФОРМИРОВАНИЯ ПЛОЩАДИ ЛИСТЬЕВ СОРТАМИ ЯРОВОЙ ТВЁРДОЙ ПШЕНИЦЫ НА ФОНЕ РАЗЛИЧНЫХ ПРИЁМОВ ОСНОВНОЙ ОБРАБОТКИ ПОЧВЫ В УСЛОВИЯХ ОРЕНБУРГСКОГО ПРЕДУРАЛЬЯ

The article contains results of field experiments (based on measuring 2 upper leaves area) on spring durum wheat varieties, which were seeded according to different expedients of basic tillage under the conditions of Orenburg Cis-Urals. It was noticed that the explored factors are highly interrelated with quantity and weight of grains in the main spike, and there was also variety reaction based on 2 upper leaves area depending on expedients of basic tillage. Also direct dependence of accumulation of solid by plants of spring-sown soft field from the area of 2 top leaves in phases of a kushcheniye, an exit in a tube and full ripeness is established. The optimality of the sizes of a sheet surface is defined from weather factors. Formation of the area of 2 top leaves of spring-sown firm field in the conditions of the Orenburg Cis-Urals characterizes reaction of culture to degree of usefulness of weather conditions of the period of vegetation and agrotechnical factors, in particular, to methods of the main processing of the soil. Proceeding from results of a research, we find possible application in selection practice of droughty zones evaluating grades on the basis of the area of leaves of two top tiers as indicator of potential efficiency.

Temporal information in tones, broadband noise, and natural vocalizations is conveyed by differential spiking responses in the superior paraolivary nucleus.

Communication sounds across all mammals consist of multiple frequencies repeated in sequence. The onset and offset of vocalizations are potentially important cues for recognizing distinct units, such as phonemes and syllables, which are needed to perceive meaningful communication. The superior paraolivary nucleus (SPON) in the auditory brainstem has been implicated in the processing of rhythmic sounds. Here, we compared how best frequency tones (BFTs), broadband noise (BBN), and natural mouse calls elicit onset and offset spiking in the mouse SPON. The results demonstrate that onset spiking typically occurs in response to BBN, but not BFT stimulation, while spiking at the sound offset occurs for both stimulus types. This effect of stimulus bandwidth on spiking is consistent with two of the established inputs to the SPON from the octopus cells (onset spiking) and medial nucleus of the trapezoid body (offset spiking). Natural mouse calls elicit two main spiking peaks. The first spiking peak, which is weak or absent with BFT stimulation, occurs most consistently during the call envelope, while the second spiking peak occurs at the call offset. This suggests that the combined spiking activity in the SPON elicited by vocalizations reflects the entire envelope, that is, the coarse amplitude waveform. Since the output from the SPON is purely inhibitory, it is speculated that, at the level of the inferior colliculus, the broadly tuned first peak may improve the signal-to-noise ratio of the subsequent, more call frequency-specific peak. Thus, the SPON may provide a dual inhibition mechanism for tracking phonetic boundaries in social-vocal communication.

Effects of wheat-rye translocations on the combining ability of winter bread wheatcultivars

The aim and tasks of the study. The purpose was to study the combining ability of winter bread wheat cultivars – carriers of wheat-rye translocations (WRT) for performance elements to determine their breeding values and to simulate selection of high-yielding offspring. Results and discussion. The results of analysis of variance attest to strong effects both of the general combining ability (GCA) and of the specific combining ability (SCA) for performance elements in the cultivars under investigation. At the same time, the mean square variance of the GCA was higher than that of of the SCA. Thus, we can affirm that additive effects dominate in the genetic control of the bread winter wheat performance elements, since the ratio of variances was >1.We distinguished the cultivars with a high GCA in F1for performance elements: Smuhlianka – the spikelet number in the main spike, 1000-grain weight, grain weight per plant; Epokha Odeska – the grain number in the main spike; Kryzhynka – 1000-grain weight; Rozkishna – grain weight from the main spike and grain weight per plant. Smuhlianka was distinguished among the others due to its with high and intermediate effects of the GCA. Kryzhynka, Rozkishna, and Epokha Odeska were some what inferior to it. Estimation of the combining ability suggests Smuhlianka as the best donor of grain productivity elements. According to the SCA constants, all the studied wheat cultivar shad intermediate indices for the most traits in 2014–2015. Cultivars with WRT were not distinguished by stable constants of the SCA and were not inferior tothe other studied cultivars, except Epokha Odeska. High constants of the SCA for some traits in WRT carriers indicate increased variability of the trait under investigation. Therefore, these cultivars may have specific hybrid combinations both with overexpression and with under expression of an inherited trait.Conclusions. Cultivars with wheat-rye translocations – Smuhlianka and Kryzhynka are of the highest value for breeding as components in crossings, providing formation of promising populations for selection of elite plants with increased performance.

The Influence of Nitrogen Fertilization and Fungicides Treatments on Yield and Quality Obtained from Various Premium Wheat Varieties

Abstract This study analyzes the results obtained during the agricultural year 2015-2016 on the PHD thesis research field and was carried out on a series of 6 wheat varieties (Triticum aestivum L.), of which 5 Premium wheat varieties and one Class A variety. The purpose of this research is to stimulate the expansion of Premium wheat varieties surfaces in Romania. Due to the superior quality of the grains (protein> 14.5%) their use in bakery, will reduce the use of synthesis enhancers. The location of the experimental field was carried out in Draganesti-Vlasca area, at SCDA Teleorman. The aim was to establish optimal technology to maximize the quantity and quality of the yield. Given the crop rotation after peas, the behavior of the wheat varieties was observed on different nitrogen doses. There were applied 3 fertilization fractions with nitrogen (N1-N3) and 3 treatments with fungicides (V1-V3). Determinations of the main foliar and spike diseases were made. The correlation between fertilizer and fungicide treatments showed the differences between yield potential and disease tolerance of the analyzed varieties.

Genetic Behavior of Some Agronomic Characters in Three Bread Wheat Crosses under Different Environmental Conditions

This investigation was carried out at the Experimental Farm of Gemmeiza Agriculture Research Station, Egyptduring the three successive seasons,i.e., 2015/2016, 2016/2017 and 2017/2018 to study nature of gene action for yield andits components, heterosis expression, heritability and expected genetic advance under normal and water stress conditions.Six populations model (P1, P2, F1, F2, BC1 and BC2) was used in this study for three crosses; (I) Gemmeiza 11× Giza168, (II) Giza 171× Shandawel 1 and (III) Gemmeiza 9× Misr1. Means of the six generations were recorded for eightcharacters, i.e. number of spikes per plant, plant height, main spike length, number of spikelets per main spike, number ofkernels per main spike, main spike yield, grain yield per plant and 1000- kernels weight. Results revealed that thecoincidence of sign and magnitude of heterosis and inbreeding depression was also detected for most characters in thethree crosses under both conditions. Study of generation means analysis revealed that additive, dominance and epistasiceffects were involved in the inheritance of yield and its components. Additive (a) and dominance (d) genes effects weresignificant for most studied characters under both conditions. High heritability estimates in broad sense were detected forall studied characters in the three crosses under both conditions, except, main spike yield in the first cross under stress.Narrow sense heritability estimates were found to be high for most characters under both conditions. Moderate to highgenetic advance (Δg%) was detected for all characters of the three crosses under the two environments, except, plantheight for the three crosses under normal condition and first and second cross under stress condition. The highestestimates of narrow sense heritability associated with highest genetic advance for most of the studied characters in most ofcrosses under both conditions indicated sufficient improvement of the variable characters. These results indicated thepossibility of practicing selection in early generations for these characters.

APPLICATION OF AUGMENTED DESIGNS FOR FIELD EVALUATION OF BREAD WHEAT DOUBLED HAPLOID LINES: A PRELIMINARY REPORT

Doubled-haploid is an effective method to produce 100% homozygous lines in asingle generation accelerating the release of new varieties and reducing thecorresponding expenses. However, the existing problem in cases where theadequate quantity of seeds is limited is the inability to evaluate new germplasm inreplicated experiments. In his attempt to confront this problem, Petersen proposedin 1985 the evaluation of new germplasm to be based on its division in blocks andselection to be performed regarding the yield of the randomly repeated control ineach block. The aim of the present study was to use the aforementioned method toevaluate preliminary 37 doubled-haploid lines (DHL). The parental varieties of theDHLs,Greek cultivars “Acheloos” and “Vergina”, were used as controls. For thepurpose of the study, 35 main spikes, one form each DHL and control, were used.The length of the spikes was measured, the number of spikelets was counted, andthe 1000 kernel weight and total yield were recorded. The data analysis revealedthat only one line exceeded the mean number of spikelets of the controls, oneexceeded the mean yield of the controls and two exceeded the mean 1000 kernelweight of the controls (one was even better than the best control). The reportedresults indicate the presence of valuable genetic variability among the DHL aftercrossing cultivars “Acheloos” x “Vergina”. Further research is needed, after DHLsmultiplication, using more plants and locations to draw more reliable conclusions.

Phenotypic and genetic variability, heritability and genetic advance for quantitative traits of two-rowed spring barley in Forest-steppe of Ukraine

The paper covers the results of three-year (2012–2014) studies by statistical genetic parameters of the main economically important quantitative traits in two-rowed spring barley accessions of different ecological origin under environments of the V.M. Remeslo Myronivka Institute of Wheat of NAAS. Phenotypic (PCV) and genotypic (GCV) coefficients of variation were from low to moderate level depending on the trait and year of the study: PCV = 3.69–17.22%, GCV = 3.66–14.73%. The highest values for all years were noted for the grain weight per plant: PCV = 14.32–17.22%, GCV = 12.01–14.73%, the lowest values were noted for 1000 grain weight: PCV = 3.69–5.96%, GCV = 3.66–5.93%. Heritability coefficient in the broad sense varied from H2 = 70.34% for the grain weight per plant to H2 = 98.94% for 1000 grain weight. The highest indices of expected genetic advance as percent of mean (GAM) was noted for the main spike length: GAM = 24.82–26.92%, for grain weight per plant: GAM = 20.74–25.95%, for grain weight per main spike: GAM = 18.87–23.81%. The peculiarity revealed indicated that when reasonable selecting the components of crosses, it is possible to obtain breeding advance of moderate to high level for most traits.

Associations between Plant Density and Yield Components Using Different Sowing Times in Wheat (Triticum aestivum L.)

The yield potential of wheat depends not only on genetic × environmental interactions, but also on various agronomic factors such as sowing date or the seed rate used for sowing. The main aim of this work was to determine possible correlations between the effects of different sowing dates and plant densities on the yield components of a collection of 48 wheat genotypes. Two-way analysis of variance on the data revealed that both sowing date and plant density, as main components, only had a minor effect on the yield component patterns. Correlation analysis, however, indicated that the sowing date had a greater effect on the yield components, while plant density was in closer correlation with the heading time (r = 0.90). The patterns determined for individual yield components at two different sowing dates and plant densities showed significant differences for spike length, spike fertility, grain number in the main spike, number of productive tillers, grain number on side tillers, mean grain number and grain weight. Genotypes that carry the winter (recessive) alleles of genes regulating vernalisation processes (VRN-A1, VRN-B1, VRN-D1) and the sensitive (recessive) alleles of the two genes responsible for photoperiod sensitivity (PPD-B1, PPD-D1) may have better tillering and consequently higher grain yield, though this may depend greatly on the year.

Влияние метеоусловий вегетации на содержание фотосинтетических пигментов в листьях мягкой яровой пшеницы

Under the conditions of the Kirov region the state of the pigment complex of leaves of soft spring wheat of 2 varieties and 9 promising lines was studied during “tillering - flowering” period to determine the influence of weather conditions in years contrasting in moisture availability and temperature indicators. During the study period of 2016-2017, the content of chlorophylls (Chl a, Chl b) and carotenoids (Car) in the majority of genotypes in one and the same phases of plant development statistically significantly varied (at p ≤ 0.05). The C-65, C-122 and C-129 lines were selected, the leaves of which contained more than the average of the experiment or an equal amount of pigments. It is shown that vegetation conditions had a greater impact on the quantitative content of pigments, and to a lesser extent on their ratio. An insignificant and medium (7.1 - 14.5%) inter-varietal variability in the content of Chl a in the reaction centers (RC) of photosystems, Chl b and Car in the leaves was noted. The average variability noted in the flowering phase allows to use the absolute values of the pigment content as an additional component in the selection of breeding lines. Under conditions of excessive moisture, paired correlations (at p ≤ 0.05) were found between plant height and Chl a and Chl b content in the tillering phase (r = -0.67 and -0.69, respectively), and also with Car content in the flowering phase (r = -0,65). The number of Chl a, Chl b and Car in the phase of entering the tube was statistically significantly correlated with productive bushiness (r = 0.67, 0.64 and 0.68, respectively), the number of grains of the main spike (r = 0.70, 0.63 and 0.68) and the mass of grain per plant (r = 0.69, 0.61 and 0.73). Under drought conditions, the content of Chl a and Chl b was significantly correlated with the length of the main spike (r = 0.71 and 0.65, respectively) and the mass of the main spike grain (r = 0.73 and 0.77). An assessment of genotype-environment interactions between the same parameters characterizing the pigment complex in different years showed that the growing season conditions strongly influenced the severity of most of them. Weak interaction genotype - year was manifested by the Car content in 1 g of dry matter in the flowering phase (r g = 0.61).

Heat Stress during Flowering Affects Time of Day of Flowering, Seed Set, and Grain Quality in Spring Wheat

ABSTRACTFlowering in wheat (Triticum aestivum L.) is highly sensitive to heat stress. Eleven spring wheat genotypes were exposed to heat stress (34/16°C, day/night temperature) during flowering to investigate the impact on time of day of flowering, seed set, grain yield, and quality under controlled environment chambers. In general, all 11 wheat genotypes recorded peak flowering during cooler hours of the day (i.e. either early in the morning or late in the evening). The trend was more pronounced under heat stress, providing first evidence of an alternative mechanism (i.e. heat escape in wheat minimizing damage during flowering). On average, significant reduction in net CO2 assimilation (17%), starch (25%), and protein content in grain (21%), seed set (7–19%), kernel weight (11–15%), and grain yield (22–38%), but with 17% increase in flag leaves proline concentration, was recorded under heat stress over control. The negative impact of heat stress on seed set was greater among the primary spikes than for the main spike. This differential impact is mainly attributed to limited plasticity of early reproductive processes such as gametogenesis to escape heat stress, unlike heat escape phenomena observed at flowering. KSG1203 and KSG41 exhibited heat escape strategy, whereas KSG1194 emerged as a true heat‐tolerant line. Systematic characterization of time of day of flowering to introduce the heat escape trait and developing heat tolerance strategies for early reproductive stages in ongoing wheat breeding programs is an ideal strategy to minimize heat stress damage.

Response of Wheat Yield, Its Components and Technological Characteristics to Different Nitrogen Rates and Planting Methods

TWO FIELD trials were conducted at the Agricultural Experiment Station, Faculty of Agriculture Ain Shams University, Kalubia, Egypt during 2013/2014 and 2014/2015 growing seasons to investigate the response of wheat to nitrogen fertilizer rates under different planting methods. Each experiment contained twelve treatments which were the combination of four planting methods (broadcasting (conventional tilled flat method), rows (20cm apart), ridge (ridge width 60 cm) and bed (bed width 120 cm)) and three nitrogen fertilizer rates (60, 80 and 100 kg Nitrogen/ fad (faddan = 4200 m2)). Design of experiments was split plot design with three replications where planting methods in the main plot and nitrogen rates in the sub plots. Data indicated that applying 100 kg N/fad gave the highest yield attributes, which reflected its yield parameters and produced significant maximum grain yield (3421.6 kg/fad) followed by 80 kg N/fad (3158.0 kg/fad) and 60 kg N/fad (2574.9 kg/fad). Applied 100 kg N scored maximal test weight, 1000 grain weight, vitreosness, wet and dry gluten. Highest number of grains per main spike was obtained when crop was sown on raised bed (68.33 grain/main spike) versus the minimal value in case of sowing broadcasting (58.78 grain/main spike). In addition, all studied yield parameters gave the highest valuses due to sowing on raised bed than others planting methods. Grain, straw and biological yields were at maximal values when wheat plants sown on raised bed being 3334.0, 5175.6 and 8487.4 kg/fad, respectively. On other hand, vitreosness, wet and dry gluten scored the highest values when wheat plants were sown in broadcasting. Meanwhile, the application of 80 kg N/fad exhibited maximum values of main spike weight (6.08 g) and grains No of main spike (72.33 grains/main spike) with sowing wheat plants on raised bed. Grain yield was at the maximal values (3604.0 kg/fad) when wheat plants were sown on raised bed with application of 80 kg N/fad. Test weight, 1000-grain weight, and dry gluten were significantly varied among nitrogen fertilizer rates and sowing methods.