Facultative Wheat Research Articles

Effects of sowing date and nitrogen applications on the energy efficiency of facultative wheat (Triticum aestivum L.) in a Pannonian environment

Energy efficiency analysis provides a deeper understanding of non-renewable energy dependent cropping systems. In this study, we examined the crop yield and energy efficiency of facultative rainfed wheat (WW – winter wheat, WS – spring wheat) and mineral nitrogen (N) fertilization (0, 50, 100, 150, and 200 kg N ha−1) in two growing seasons 2019/20 and 2020/21 in Central Europe. WW out performed WS significantly overall (2019/20: +30.3 to +47.9 %; 2020/21: +18.9 to +37.3 %) in terms of energy efficiency indicators. The impact of N fertilization on energy efficiency was minimal, largely due to one dose application of mineral N fertilizer. The highest estimated net-energy output (NEO) was observed at 160.2 kg N ha−1, which may not sustainable for this pedo-climatic region due to potential N emissions risks. Zero N fertilization showed best performance in terms of energy use efficiency (EUE), energy intensity (EI), and energy productivity (EP). The ERG z-score, which combines NEO and EUE into a single bi-dimensional indicator, indicated an optimal N fertilization level of 72.0 kg N ha−1.

Registration of ‘FL16045‐25’: An early‐maturing, high‐yielding, disease‐resistant soft red facultative wheat cultivar for the southern United States

Abstract‘FL16045‐25’ (Reg. no. CV‐1207, PI 704484), a soft red, facultative doubled‐haploid wheat (Triticum aestivum L.) cultivar, was developed and tested as FL16045DH‐25 by the University of Florida and released in October 2022. FL16045‐25 was derived from the cross MD07W478‐14‐5/GA06112‐13EE16. It is well adapted from Texas to Virginia and provides producers with an early‐season, facultative (Vrn‐A1_short), medium‐height, awned, semi‐dwarf (Rht2) cultivar that has high yield potential, good straw strength, good grain volume weight, and good end‐use quality. It expresses moderate‐to‐high levels of resistance to most diseases prevalent in the southern United States. Molecular marker analysis confirms the presence of Sbm1, Yr17/Lr37/Sr38, Lr18, Sr36/Pm6, Pm54, and Pm1a‐linked disease‐resistant genes. The yield average of FL16045‐25 from 41 environments during 2020–2022 ranged from 4211 to 5782 kg ha−1, which is competitive with check cultivars that are widely used in the southern part of the United States. The grain volume weight of FL16045‐25 ranged from 749 to 785 kg m−3 (32 environments), which was higher than most of the checks. FL16045‐25 has soft grain texture with softness equivalence varying from 51.3% to 59.3% and sodium carbonate solvent retention capacity (SRC) ranging from 66.8% to 68.5%. Flour yields on a Quadrumat Senior milling system varied from 68.7% to 69.5%. Flour protein content varied from 8.9% to 9.1%. Cookie spread diameter varied from 19.4 to 19.5 cm. The presence of TaSus2‐2B, Sucrose Synthase2 gene on 2B or 2G:2B, was confirmed by marker analysis.

СОРТА ДВУРУЧКИ КАК ИСХОДНЫЙ МАТЕРИАЛ ДЛЯ СЕЛЕКЦИИ ЯРОВОЙ ПШЕНИЦЫ В СЕВЕРНОЙ ЛЕСОСТЕПИ ТЮМЕНСКОЙ ОБЛАСТИ

The objective of research is to study the facultative wheat varieties bred by the Krasnodar Research Institute of Agriculture for a set of economic traits and to establish the possibility of using them in the bree-ding of spring wheat in the Tyumen Region. Research was conducted in 2022–2023 on a small experimental field of the Northern Trans-Urals State Agricultural University. The object of research is five facultative wheat varieties (Anka, Afina, Leo, Karavan, Velena) bred by the Krasnodar Research Institute of Agriculture and the standard spring wheat variety Ikar. It was found that facultative wheat varieties, when sown early (soil temperature 8–10 °C), grow and develop well and, at the same time as the standard spring variety Ikar, reach economic grain maturity at the end of August. They form stems 80–90 cm high with shortened lower internodes, dense straw walls (weight of 1 cm of straw is 23.1–27.5 mg, for the standard – 19.7 mg) and are resistant to lodging. In terms of field germination and survival of plants for harvesting, the diurnal varieties exceeded the standard Ikar variety by 13–18 and 12–17 %, respectively. In terms of resistance to brown leaf and stem rust, powdery mildew and septoria, they were rated at 7–9 points. Productive tillering was one and a half to two times higher than that of the standard Ikar variety and amounted to 2–4 stems per plant. Due to the high grain content per ear (23–28 pcs.) and average grain size (34.3–37.1 g), the grain weight per ear was 0.82–1.14 g, which is 0.12–0.44 g higher than that of the standard Ikar variety. In terms of protein and gluten content in grain, as well as grain bulk density, vitreousness, and falling number, the facultative varieties generally met the requirements for valuable and strong wheat. According to the studied economic characteristics, facultative wheat varieties are valuable source material for breeding spring wheat in the Tyumen Region.

Population Genetic Analysis of a Bread Wheat Panel from Northern and Huang-Huai Agro-Ecological Regions in China

Bread wheat (Triticum aestivum L.) is one of the most extensively cultivated cereal crops around the world. Here, we investigated the population structure and genetic diversity of a panel mainly originated from two wheat agro-ecological regions (northern winter wheat region, NW; and the Huang-Huai River Valley’s facultative wheat region, HH) in China based on a 15K SNP array. Population genetic analysis revealed that the optimal population number (K) was three, and the three groups were roughly related to ecological regions, including NW (mainly Hebei), HH1 (Henan-Shaanxi), and HH2 (Shandong). Within HH, HH1 had a higher nucleotide diversity (π = 0.31167), minor allele frequency (MAF = 0.2663), polymorphism information content (PIC = 0.2668), and expected heterozygosity (Hexp = 0.3346) than HH2. Furthermore, our results demonstrated that genetic diversity decreases with the advancement of wheat breeding. Finally, inference of ancestry informative markers indicated that the genomes of the three pure groups from the three provinces (Hebei, Henan, and Shandong) of the two regions have genomic regions with different mosaic patterns derived from the two landrace groups. These findings may facilitate the development of wheat breeding strategies to target novel desired alleles in the future.

Optimal environmental design of nitrogen application rate for facultative wheat using life cycle assessment

Nitrogen (N) supply is a relevant factor in wheat production, affecting yield and yield components. However, this input plays a dominant role in the environmental impact level arising within all the on-farm growing processes. To assess the effects of N fertilization on environmental impact levels, the agricultural life cycle assessment (LCA) was performed for facultative wheat as affected by sowing date (autumn versus spring) and N fertilization (0, 50, 100, 150, and 200 kg ha−1) on a chernozem soil under Pannonian conditions in Eastern Austria for two years (2019/2020 and 2020/2021). In this study, an LCA was performed to find the optimal cropping design to achieve a low environmental impact with an adequate yield level. Processes from cradle to farm gate were involved within the system boundary. As the functional units, grain N yield and land demand for generating the same grain N yield were used. SimaPro software and the ReCiPe 2016 method with Midpoint and Endpoint characterization model were involved. Data were interpreted for 18 impact categories. From an environmental point of view, wheat crops with high doses of N (˃ 150 kg ha−1) were associated with the highest environmental impact. The appropriate grain N yield should be reached to balance the environmental impact resulting from the fertilizer application and all the other inputs. A sufficient increase in yield must be achieved with increased fertilization to justify additional emissions that are related to N fertilization. Variants of winter wheat with medium inputs of N (between 100 and 150 kg ha−1) were associated with the lowest impact on the environment. Consequently, according to environmental impact assessment, it is disadvantageous not to fertilize wheat with N or, on the contrary, to over-fertilize it with N.

Effects of genetic components of plant development on yield-related traits in wheat (Triticum aestivum L.) under stress-free conditions.

The dynamics of plant development not only has an impact on ecological adaptation but also contributes to the realization of genetically determined yield potentials in various environments. Dissecting the genetic determinants of plant development becomes urgent due to the global climate change, which can seriously affect and even disrupt the locally adapted developmental patterns. In order to determine the role plant developmental loci played in local adaptation and yield formation, a panel of 188 winter and facultative wheat cultivars from diverse geographic locations were characterized with the 15K Illumina Single Nucleotide Polymorphism (SNP) chip and functional markers of several plant developmental genes and included into a multiseason field experiment. Genome-wide association analyses were conducted on five consecutive developmental phases spanning from the first node appearance to full heading together with various grain yield-related parameters. The panel was balanced for the PPD-D1 photoperiod response gene, which facilitated the analyses in the two subsets of photoperiod-insensitive and -sensitive genotypes in addition to the complete panel. PPD-D1 was the single highest source, explaining 12.1%-19.0% of the phenotypic variation in the successive developmental phases. In addition, 21 minor developmental loci were identified, each one explaining only small portions of the variance, but, together, their effects amounted to 16.6%-50.6% of phenotypic variance. Eight loci (2A_27, 2A_727, 4A_570, 5B_315, 5B_520, 6A_26, 7A_1-(VRN-A3), and 7B_732) were independent of PPD-D1. Seven loci were only detectable in the PPD-D1-insensitive genetic background (1A_539, 1B_487, 2D_649, 4A_9, 5A_584-(VRN-A1), 5B_571-(VRN-B1), and 7B_3-(VRN-B3)), and six loci were only detectable in the sensitive background, specifically 2A_740, 2D_25, 3A_579, 3B_414, 7A_218, 7A_689, and 7B_538. The combination of PPD-D1 insensitivity and sensitivity with the extremities of early or late alleles in the corresponding minor developmental loci resulted in significantly altered and distinct plant developmental patterns with detectable outcomes on some yield-related traits. This study examines the possible significance of the above results in ecological adaptation.

Yield and yield components of facultative wheat are affected by sowing time, nitrogen fertilization and environment

Production of wheat (Triticum aestivum L.) is affected by changing weather conditions, which are difficult to predict especially under climate change. Therefore, facultative varieties can be beneficial, because of their high adaptability in sowing time. Information on yield and yield components of facultative wheat in temperate climate, however, is limited. Therefore, a two-factorial experiment with the factors sowing time (autumn versus spring) and nitrogen fertilization (0, 5, 10, 15 and 20 g m−2) was conducted on a chernozem soil under Pannonian conditions in Eastern Austria in two seasons to assess the effects of sowing time, nitrogen fertilization and environment on yield and yield components of one facultative wheat variety. The experimental data were analyzed using principal component analysis and quantitative mixed model analysis. Grain yield of autumn-sown wheat was higher at 0 g N m−2 and featured a higher increase with additional nitrogen fertilization compared to spring-sowing. At high nitrogen fertilization rates above 15 g m−2, grain yield showed no response to further nitrogen fertilization. Based on ear density, grains per ear, thousand kernel weight and harvest index, the other yield and yield component parameters investigated in this study can be calculated. Ear density showed an increase with additional nitrogen fertilization, which was higher for autumn-sowing than spring-sowing. Differences in environmental conditions resulted in higher variation of grains per ear and thousand kernel weight for spring-sowing compared to autumn-sowing. Ear density, grains per ear, thousand kernel weight and harvest index featured dependencies among each other and were affected by environmental conditions during relevant developmental stages, e.g., tillering until anthesis for ear density and grains per ear as well as grain filling period after anthesis for thousand kernel weight and harvest index.

Erratum to: Effects of Sowing Dates and Seeding Rates on Nitrogen and Water Use Efficiency of Facultative Wheat

Erratum to: Effects of Sowing Dates and Seeding Rates on Nitrogen and Water Use Efficiency of Facultative Wheat

Effects of Sowing Dates and Seeding Rates on Nitrogen and Water Use Efficiency of Facultative Wheat

Effects of Sowing Dates and Seeding Rates on Nitrogen and Water Use Efficiency of Facultative Wheat

Genetic Dissection of Adult Plant Resistance to Sharp Eyespot Using an Updated Genetic Map of Niavt14 × Xuzhou25 Winter Wheat Recombinant Inbred Line Population.

Wheat sharp eyespot, a disease mainly caused by soilborne fungus Rhizoctonia cerealis, is a threat to world wheat production. Wheat's genetic resistance to sharp eyespot is a potential approach to reducing the application of fungicides and farming practice inputs. To identify the genetic basis of sharp eyespot resistance in Niavt14, a recombinant inbred line population comprising 215 F8 lines from Niavt14 × Xuzhou25, was developed. An earlier linkage map (148 simple sequence repeat markers) was updated with 5,792 polymorphic Affymetrix Axiom 55K single-nucleotide polymorphisms to a new map of 5,684.2 centimorgans with 1,406 nonredundant markers. The new linkage map covered all 21 chromosomes of common wheat and showed a good collinearity with the IWGSC RefSeq v1.0 genome. We conducted quantitative trait locus (QTL) mapping for sharp eyespot resistance using the adult plant response data from the field of five consecutive growing seasons and one greenhouse test. Two stable QTL on chromosomes 2B and 7D that were identified in the previous study were confirmed, and three novel, stable QTL, explaining 4.0 to 17.5% phenotypic variation, were mapped on 1D, 6D, and 7A, which were independent of QTL for phenology and plant height. The QTL on 1D, 2B, 6D, and 7A showed low frequencies in 384 landraces (0 to 10%) and 269 elite cultivars (5 to 23%) from the southern winter wheat region and the Yellow and Huai River Valley facultative wheat region in China, respectively. These identified QTL could be used in wheat breeding programs for improving sharp eyespot resistance through marker-assisted selection.

Multi-Trait Genomic Prediction of Yield-Related Traits in US Soft Wheat under Variable Water Regimes.

The performance of genomic prediction (GP) on genetically correlated traits can be improved through an interdependence multi-trait model under a multi-environment context. In this study, a panel of 237 soft facultative wheat (Triticum aestivum L.) lines was evaluated to compare single- and multi-trait models for predicting grain yield (GY), harvest index (HI), spike fertility (SF), and thousand grain weight (TGW). The panel was phenotyped in two locations and two years in Florida under drought and moderately drought stress conditions, while the genotyping was performed using 27,957 genotyping-by-sequencing (GBS) single nucleotide polymorphism (SNP) makers. Five predictive models including Multi-environment Genomic Best Linear Unbiased Predictor (MGBLUP), Bayesian Multi-trait Multi-environment (BMTME), Bayesian Multi-output Regressor Stacking (BMORS), Single-trait Multi-environment Deep Learning (SMDL), and Multi-trait Multi-environment Deep Learning (MMDL) were compared. Across environments, the multi-trait statistical model (BMTME) was superior to the multi-trait DL model for prediction accuracy in most scenarios, but the DL models were comparable to the statistical models for response to selection. The multi-trait model also showed 5 to 22% more genetic gain compared to the single-trait model across environment reflected by the response to selection. Overall, these results suggest that multi-trait genomic prediction can be an efficient strategy for economically important yield component related traits in soft wheat.

Yield and Profitability of Crop Production in Mountain Less Favoured Areas

Agricultural production is a crucial part of policy issue in preventing depopulation of mountainous areas across Europe. However, soil and climate conditions are limiting yields and profitability of crop production in these regions. The European Union (EU) subsidizes agriculture in mountains by special payments (Less Favoured Area (LFA) subsidy) when areas match law-specified natural handicaps. This study aims to assess whether LFA subsidy in Poland is sufficient to cover losses caused by lower yields of crops cultivated in a mountainous region of Poland (Low Beskid Mountains in Carpathians) compared to lowland regions (non-LFA areas). The results indicated that LFA subsidy was adequate for crops (facultative wheat, winter wheat, field bean and spring barley) grown in the years 2015–2018.

SEARCH FOR THE CORRELATION BETWEEN ALLELIC POLYMORPHISM OF THE PPD AND VRN GENES WITH THE VARIABILITY OF THE MAIN ECONOMICALLY VALUABLE TRAITS OF WINTER BARLEY

Winter barley is an important agricultural crop whose grain is used for fodder and food purposes. The main advantage of winter barley over spring barley is in an earlier ripening period, the ability to use winter and early spring moisture reserves, due to which winter barley produces a yield in 1.5–2 times higher than spring barley. Because of increasing climate aridity in the south of the country, the development of early ripening winter barley varieties, as well as varieties with an alternative type of development (facultative wheat) is of great importance. The length of the growing period (especially ‘sprouts-earing’ phase) and responsiveness to barley vernalization is controlled by the Ppd and Vrn genetic systems. It is known that the Ppd and Vrn genes have a pleiotropic effect, that is, they affect many traits, including the general adaptability and seed productivity of plants. Therefore, among the analyzed traits, the dependence of which on the allelic diversity of the genes is required to be established, there should be present not only the starting time of earing and responsiveness to vernalization, but also other economically valuable traits (productivity parameters, lodging degree, etc.). The purpose of the study was to establish the influence of allelic polymorphism of the studied genes on the variability of the main economically valuable traits. The object of the research was 94 varieties of local (Zernograd, Rostov region, Russia) and other district breeding. It has been identified that the research tests were successful for only one of the five tested marker systems. It was the marker system for the Vrn-H2 gene, which determines the type of barley development (winter, spring, facultative). The polymorphism of the Vrn-H2 gene significantly influences on the protein percentage in the kernels and on the resistance of varieties to lodging.

Characterization of Pm65, a new powdery mildew resistance gene on chromosome 2AL of a facultative wheat cultivar.

A new powdery mildew resistance gene that can be readily used in wheat breeding, Pm65, was identified in the facultative wheat cultivar Xinmai 208 and mapped to the terminal region of chromosome 2AL. Wheat powdery mildew, a widely occurring disease caused by the biotrophic fungus Blumeriagraminis f. sp. tritici (Bgt), poses a serious threat to wheat production. A high breeding priority is to identify powdery mildew resistance genes that can be readily used either alone or in gene complexes involving other disease resistance genes. An F2 population and 227 F2:3 families derived from the cross Xinmai 208 × Stardust were generated to map a powdery mildew resistance gene in Xinmai 208, a high-yielding Chinese wheat cultivar. Genetic analysis indicated that Xinmai 208 carries a single dominant powdery mildew resistance gene, designated herein Pm65, and linkage analysis delimited Pm65 to a 0.5cM interval covering 531.8Kb (763,289,667-763,821,463bp) on chromosome 2AL in the Chinese Spring reference sequence. An allelism test indicated that Pm65 is a new gene about 10.3cM distal to the Pm4 locus. Pm65 was 0.3cM proximal to Xstars355 and 0.2cM distal to Xstars356. It conferred near-immunity to 19 of 20 Bgt isolates collected from different wheat-growing regions of the USA. Coming from a high-yield potential cultivar, Pm65 can be directly used to enhance powdery mildew resistance in wheat. The newly developed SSR markers Xstars355 and Xstars356 have the potential to tag Pm65 for wheat improvement.

Genome-wide association mapping of root system architecture traits in common wheat (Triticum aestivum L.)

Uncovering the genetic basis and optimization of root system architecture (RSA) traits are crucial for modern wheat breeding. Genome-wide association mapping has become a powerful approach to dissect the genetic architecture of complex quantitative traits. In the present study, RSA traits, viz. total root length (TRL), total root area, average root diameter and number of root tips in a diverse panel of 165 elite wheat cultivars from the Yellow and Huai River Valley Facultative Wheat Region of China were evaluated as seedlings in hydroponic culture and in the field to identify loci significantly associated with those traits. The diverse panel was genotyped using the wheat 90 K and 660 K SNP arrays, and a genome-wide association study using a mixed linear model identified 28 and 4 loci significantly associated with RSA traits in hydroponic culture and in the field, explaining 8.8–15.6% and 8.9–12.6% of phenotypic variances, respectively. Seven loci for RSA traits co-located with known genes or quantitative trait loci (QTL), whereas the other 22 were potentially new. Linear regression between favorable alleles and RSA traits suggested that QTL pyramiding should be effective in optimizing root systems. Two candidate genes for RSA traits were identified, including genes encoding calcium dependent protein kinase and E3-Ubiquitin protein ligase. This study provides novel insights into the genetic architecture of RSA traits.

Dual-purpose cereals offer increased productivity across diverse regions of Australia’s high rainfall zone

Dual-purpose (DP) cereals provide an opportunity to graze vegetative crops in autumn and winter when pasture forage levels are low, and then harvested for grain after the exclusion of stock. The dual use provides significant increases in mixed farm returns and the area of DP crops is expanding from traditional areas in south-eastern Australia. DP crops have particular potential in the 9 M ha high rainfall zones (HRZ, >500–600 mm annual rainfall) where the crop growing season is longer, increasing the potential grazing period and the capacity to recover high grain yield. To capitalise on this potential, management packages that combine the most suitable varieties and sowing times to maximise forage and grain production are required. We conducted six experiments across the south-eastern, north-eastern and south-western regions of Australia’s HRZ to assess potential forage and grain production of DP cereal species (wheat, barley and triticale) and phenology types. In the south-eastern HRZ, slow winter cultivars out-performed spring types due the increased forage production in the ‘safe’ grazing period (stem elongation, DC30) providing up to 2600 DSE.days/ha and 7.5 t/ha grain yield from a mid-March sowing. Early-sown spring cultivars provided a shorter period of ‘safe’ grazing as the lack of vernalisation requirement hastened development and reduced grain yield potential. In the south-western HRZ, early sowing opportunities (March) are rare and the season much shorter. The best results were achieved with mid-April sowing of barley and longer season spring and facultative wheat, providing 640 DSE.days/ha and grain yields of 3.0 t/ha and 3.4 t/ha, respectively. In the north-eastern HRZ, grain recovery was more sensitive to grazing, however 2000 DSE.days/ha and 6.5 t/ha grain yield were achieved with winter cereals sown in early April. Grazing in the safe phenological window had no effect on grain yield in the south-west region, but reduced yield of some cultivars in the eastern regions. The reduction in grain yield of early-sown winter wheat cultivars due to grazing (17–28%) was greatest when yield potential was high (>6.8 t/ha). Overall, the experiments confirm the predicted potential for dual-purpose production of cereals across the Australian HRZ region provided appropriate cultivar and sowing dates are combined with careful grazing management. Further work is required to refine grazing management to reduce reductions in grain yield in well-managed DP crops grazed prior to stem elongation.

The influence of non-starch polysaccharide on thermodynamic properties of starches from facultative wheat varieties

The effect of sowing time of three facultative wheat varieties (late autumn or spring) on the content and properties of arabinoxylans (AX) adsorbed on the surface of starch granules in the process of washing out from flour, and the impact of AX on physicochemical properties of starch and filtration performance of enzymatic starch hydrolysates were determined in this study. The differential scanning calorimetry (DSC) was used to assess the susceptibility of native starches and starches deprived of AX to gelatinization and hydrolysis by α-amylase (under conditions used in industry). Processes of amylose–lipid complexes (AML) dissociation and re-association were monitored to determine values of transition enthalpy (ΔH), temperatures of the onset (To), peak (Tp) and completion (Tc) of the transition as well as to calculate ΔTr (Tc − To). The time of wheat sowing affected properties of AX associated with starch granules that in turn influenced the characteristics of starch and its enzymatic hydrolysates. The presence of AX in starch granules negatively affected filtration of glucose syrups obtained under the same conditions as in industry.

Genetic potential and variability for phenological and yield attributes in facultative winter wheat

To feed ever growing world population, development of high yielding and disease resistant wheat varieties are of utmost importance. A set of 20 genotypes including 18 facultative winter wheat lines and two checks (Pirsabak-2005 & Pirsabak-2013) cultivar were evaluated at Cereal Crops Research Institute (CCRI), Pirsabak Nowshera Khyber Pakhtunkhwa-Pakistan during 2014-15 cropping season. Highly significant differences (P ≤ 0.01) were found among the facultative lines for all traits except biological yield. Days to heading, maturity, plant height, biological yield, grain yield and harvest index varied from 116 to 133 days, 152 to 168 days and 87 to 128 cm, 11805.56 to 16666.67 kg ha-1, 1627.78 to 4713.89 kg ha-1 and 15.11 to 36.00% respectively. Based on mean performance, FWWL-6 was found best for days to heading and maturity as it headed and matured earlier than other lines. For reduced height, FWWL-7 was found best. Comparison of mean for grain yield showed that FWWL-14 produced the highest grain yield (4713.89 kg ha-1) as compared to other genotypes. Heritability estimates in broad sense for days to heading, maturity, plant height, grain yield, biological yield and harvest index was 0.81, 0.59, 0.86, 0.26, 0.70 and 0.83 respectively. Genetic advance (%) for days to heading, days to maturity, plant height, biological yield, grain yield and harvest index was 3.69, 2.61, 10.98, 4.83, 19.67 and 22.93 respectively. High heritability estimates for all the traits except biological yield, suggested that selection would be more effective to develop superior lines that could be used in future wheat improvement programs. Keywords: Correlation; Heritability (Broad sense); Wheat Potential; Winter wheat http://dx.doi.org/10.19045/bspab.2017.60064

Allelic variations and differential expressions detected at quantitative trait loci for salt stress tolerance in wheat

The increasing salinization of agricultural lands is a threat to global wheat production. Understanding of the mechanistic basis of salt tolerance (ST) is essential for developing breeding and selection strategies that would allow for increased wheat production under saline conditions to meet the increasing global demand. We used a set that consists of 150 internationally derived winter and facultative wheat cultivars genotyped with a 90K SNP chip and phenotyped for ST across three growth stages and for ionic (leaf K+ and Na+ contents) traits to dissect the genetic architecture regulating ST in wheat. Genome-wide association mapping revealed 187 Single Nucleotide Polymorphism (SNPs) (R2 = 3.00-30.67%), representing 37 quantitative trait loci (QTL), significantly associated with the ST traits. Of these, four QTL on 1BS, 2AL, 2BS and 3AL were associated with ST across the three growth stages and with the ionic traits. Novel QTL were also detected on 1BS and 1DL. Candidate genes linked to these polymorphisms were uncovered, and expression analyses were performed and validated on them under saline and non-saline conditions using transcriptomics and qRT-PCR data. Expressed sequence comparisons in contrasting ST wheat genotypes identified several non-synonymous/missense mutation sites that are contributory to the ST trait variations, indicating the biological relevance of these polymorphisms that can be exploited in breeding for ST in wheat.

Influence of bioactive compounds on elements of winter hardiness of bread winter wheat

Aim. To investigate the effect of bioactive compounds regulating different ways of metabolism on elements of winter hardiness in bread winter wheat varieties with different levels of this trait.Material and methods. The influence of bioactive compounds detergent Triton X-100 that causes deproteinization of cell membranes and therefore reduces their resistance to ice crystals at low temperatures and antioxidant AOK-M promoting cell survival under stressful conditions of stress on frost resistance was studied.Winter wheat varieties of different winter hardiness: Myronivska 808 (frost resistant), Myrliena (mid frost resistant), Monotyp (low frost resistant), Zymoiarka (facultative wheat) and standard variety Podolianka were studied. The seeds were treated with solutions of Triton X-100 (30 mg/l) and AOK-M (2 ml/l) before sowing.Results. With freezing temperature-20°C the antioxidant caused increase plant viability only in the least frost-resistant variety Zymoiarka. When treating seeds with detergent, reduction of this feature was noted only in some cases. Detergent processing resulted in reduction of soluble carbohydrate content in tillering nodes (prior to overwintering) in variety Myronivska 808. For Myrliena and Zymoiarka varieties same effect was caused with the antioxidant. Effect of antioxidant contributed to stable levels of carbohydrate content during wintering in all varieties studied. Action of detergent caused a deceleration of growing point elongation in plants of bread winter wheat varieties during winter.Conclusion. The studies have shown diverse trends in action character of metabolic backgrounds in varieties differing in frost resistance. Such differences are related to the physiological characteristics of varieties and formation in them various metabolic cycles being critical for their survival in winter.