Field trials were conducted to evaluate the effect of nitrogen level on wheat protein content and composition in 16 cultivars over two years at three locations. The nitrogen treatment comprised two ...nitrogen levels, 0 kg ha−1 as low and 100 kg ha−1 as high nitrogen, applied as top dressings of 50 kg nitrogen per ha at tillering and stem extension growth stages. Increased nitrogen level generally enhanced grain protein by 11.3% (11.5% vs. 12.8%). Considering protein composition determined by reversed phase–high-pressure liquid chromatography, higher nitrogen supply generally enhanced the proportion of total gliadins, α-gliadins, γ-gliadins and high-molecular-weight glutenin subunits by 1.1%, 2.0%, 3.7%, 0.6% and 0.9%, respectively, and reduced albumins and globulins, ω-gliadins, total glutenins and low-molecular-weight glutenin subunits by 1.1%, 1.7%, 1.9% and 3.2%. Under a high nitrogen level, the historical cultivars Libellula, San Pastore and U-1 had a higher protein content (13.1–15.2%) with significantly higher total gliadins, which resulted in a significantly higher gliadin/glutenin ratio (1.68–1.92). In the modern cultivars, protein content varied between 11.4% and 14.6% with a well-balanced gliadin/glutenin ratio (1.08–1.50), except for cultivar MV Nemere which had a high gliadin/glutenin ratio at both nitrogen levels (1.81 vs. 1.87). In summary, increasing nitrogen level enhanced grain protein content while the composition of gliadin and glutenin fractions was changed to a lesser extent and was largely cultivar specific and therefore should be considered for wheat baking quality assessment and breeding purposes.
Breeding for end-use quality traits is often challenging since their assessment requires larger quantities of grain and flour samples, which are usually not available early in the breeding process. ...Using the mixograph as a fast and effective method of evaluating dough quality together with genomic selection (GS) can help in pre-selecting high-performing progenies earlier in the breeding process and achieve a higher gain per unit of time and cost. In the present study, the potential of GS to predict seven end-use quality traits, including mixograph traits, in two biparental wheat populations was investigated. Field trials with both populations were conducted at two locations in Croatia (Osijek and Slavonski Brod) over three years. Results showed that the size of the training population (TP) plays an important role in achieving higher prediction accuracies, while marker density is not a major limitation. Additionally, results of the present study did not support the optimization of TP based on phenotypic variance as a tool to increase prediction accuracy. The performance of eight prediction models was compared and among them elastic net showed the lowest prediction accuracy for all traits. Bayesian models provided slightly higher prediction accuracy than the ridge regression best linear unbiased prediction (RR-BLUP) model, which is negligible considering the time required to perform an analysis. Although RR-BLUP was not the best performing model in all cases, no advantage of using any other model studied here was observed. Furthermore, strong differences between environments in terms of the prediction accuracy achieved were observed, suggesting that environments that are less predictive should be removed from the dataset used to train the prediction model. The prediction accuracies obtained in this study support implementation of GS in wheat breeding for end-use quality, including some mixograph traits.
Genotype-by-environment interaction (GEI) is often a great challenge for breeders since it makes the selection of stable or superior genotypes more difficult. In order to reduce drawbacks caused by ...GEI and make the selection for wheat quality more effective, it is important to properly assess the effects of genotype, environment, and GEI on the trait of interest. In the present study, GEI patterns for the selected quality and mixograph traits were studied using the Additive Main Effects and Multiplicative Interaction (AMMI) model. Two biparental wheat populations consisting of 145 and 175 RILs were evaluated in six environments. The environment was the dominant source of variation for grain protein content (GPC), wet gluten content (WGC), and test weight (TW), accounting for approximately 40% to 85% of the total variation. The pattern was less consistent for mixograph traits for which the dominant source of variation has been shown to be trait and population-dependent. Overall, GEI has been shown to play a more important role for mixograph traits compared to other quality traits. Inspection of the AMMI2 biplot revealed some broadly adapted RILs, among which, MG124 is the most interesting, being the prevalent “winner” for GPC and WGC, but also the “winner” for non-correlated trait TW in environment SB10.
Extended drought affects the production and quality of wheat (
L.), one of the world's most important food crops. Breeding for increased drought resistance is becoming increasingly important due to ...the rising demand for food production. Four old traditional Croatian wheat cultivars were used in the present study to examine the early antioxidant response of flag leaves to desiccant-stimulated drought stress and to identify drought-tolerant cultivars accordingly. The results indicate that the enzymatic antioxidant system plays the most significant role in the early response of adult wheat plants to drought stress and the removal of excessive H
O
, particularly GPOD and APX. Nada and Dubrava cultivars revealed the strongest activation of the enzymatic defense mechanism, which prevented H
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accumulation and lipid peroxidation. Additionally, the Nada cultivar also showed increased synthesis of proline and specific phenolic compounds, which both contribute to the increased stress tolerance. Among the cultivars investigated, cultivar Nada has the broadest genetic base, which may explain why it possesses the ability to activate both enzymatic and non-enzymatic defense mechanisms in an early response to drought stress. This suggests that old traditional wheat cultivars with broad genetic bases can be a valuable source of drought tolerance, which is especially important given the current climate change.
Field experiments were conducted, aiming to evaluate whether the late-season foliar urea application (35 kg N ha−1) is effective in improving grain yield and protein-related quality in ten common ...wheat cultivars during two consecutive growing seasons. On average, late urea application significantly (p < 0.05) increased grain yields, thousand kernel, and hectolitre weight. The total grain protein significantly (p < 0.05) increased by 17.5% under urea application, while dough mixing behaviour was improved by increasing flour water absorption and reducing the degree of softening. Considering dough elastic properties, the changes in dough energy and maximum resistance under urea application were strongly cultivar dependent and their values compared to control varying from −12.7% to +42.4% and −25.1% to +7.7%, respectively. The distribution of grain storage proteins was significantly influenced by late urea application, but to a lesser extent than the total grain proteins. The proportion of total gliadins, α- and γ-gliadins increased by 5.3%, 5.8%, and 6.5%, respectively, while total glutenins and high-molecular weight glutenins decreased by 4.5% and 7.4%, respectively. In summary, the late-season application of urea has greatly improved the protein-related quality without considerable disruption of the storage proteins composition.
An increased awareness of environmental protection and sustainable production raise the necessity of incorporating the selection of low nitrogen-tolerant winter wheat cultivars for high yield and ...quality in the breeding process. This selection can be assisted by using stress screening indices. Our study aimed to evaluate and compare a number of stress screening indices and to determine and select the most nitrogen deficiency-tolerant winter wheat cultivars for further breeding. The experiment included forty-eight winter wheat cultivars from eight different countries that were grown for two consecutive years at three different locations under low-nitrogen (LN) and high-nitrogen (HN) conditions. The results emphasized the importance of applying the appropriate stress screening indices in evaluating and selecting nitrogen deficiency-tolerant wheat cultivars. The promising stress screening indices were the mean productivity index (MP), geometric mean productivity index (GMP), harmonic mean index (HM), stress tolerance index (STI) and yield index (YI). They identified cultivars Sofru, BC Opsesija and MV-Nemere as the most tolerant cultivars to LN conditions for grain yield. The same indices classified U-1, OS-Olimpija, Forcali, Viktoria and BC Tena cultivars as the most tolerant to LN conditions for the grain protein content. Using the tolerance index (TOL), yield stability index (YSI) and relative stress index (RSI), the Katarina and Ficko cultivars were denoted as LN-tolerant cultivars in terms of the grain yield and Isengrain, Tosunbey, Vulkan and BC Darija in terms of the grain protein content.
Selection for wheat (
L.) grain quality is often costly and time-consuming since it requires extensive phenotyping in the last phases of development of new lines and cultivars. The development of ...high-throughput genotyping in the last decade enabled reliable and rapid predictions of breeding values based only on marker information. Genomic selection (GS) is a method that enables the prediction of breeding values of individuals by simultaneously incorporating all available marker information into a model. The success of GS depends on the obtained prediction accuracy, which is influenced by various molecular, genetic, and phenotypic factors, as well as the factors of the selected statistical model. The objectives of this article are to review research on GS for wheat quality done so far and to highlight the key factors affecting prediction accuracy, in order to suggest the most applicable approach in GS for wheat quality traits.
Fusarium head blight and inadequate nitrogen fertilization can cause numerous biochemical changes in wheat. The main aim of this study was to determine the effects of Fusarium inoculation and a ...broader range of different nitrogen fertilization on the defense response in the spikes of four wheat varieties, varying in FHB susceptibility. Total soluble phenolics content, activities of enzymes involved in phenol metabolism (PAL and PPO), and total antioxidant capacity were determined as indicators of defense response. In both growing seasons, Fusarium inoculation altered PHE content in wheat spikes, indicating involvement of PHE in the defense response to Fusarium attack. Increased PHE content in the partially resistant varieties (Apache and Graindor) indicates involvement of PHE in the defense response and better disease tolerance in the more resistant varieties. Breeding wheat varieties with enhanced PHE synthesis could be a promising strategy to control FHB. To the best of our knowledge, this is the first study that emphasizes the effects of Fusarium infection and a broader range of different nitrogen fertilization on PHE and enzymes involved in PHE metabolism. In addition, this is the first study using the FRAP method to determine the antioxidant capacity of wheat tissues under the influence of Fusarium infection and different nitrogen fertilization.
Fuzarijska palež klasova (FHB) pšenice ekonomski je značajna bolest koja može imati nepovoljne posljedice na prinos i kvalitetu pšenice. Do danas ne postoji mjera zaštite koja osigurava potpunu ...zaštitu usjeva pšenice, ali kombinacija više mjera može dati dobre rezultate. Učinkovitost svake pojedine mjere pod utjecajem je okolišnih uvjeta koji prevladavaju tijekom vegetacijske sezone, a učinkovitost će ovisiti i o osjetljivosti pojedine sorte na FHB. Sve veći broj istraživanja potvrđuje kako je integrirana zaštita bilja (IZB) ključ za što uspješniju borbu protiv FHB-a. Kako bi primijenjene mjere zaštite bile što uspješnije, od iznimne je važnosti dobro poznavati uzročnika bolesti, njegov životni ciklus i ekologiju. Budući da je F. graminearum dominantni uzročnik FHB-a na području Republike Hrvatske, osobiti naglasak je stavljen na sve dostupne mjere zaštite u njegovu suzbijanju.
Fusarium head blight (FHB) is an economically devastating disease that may exert an adverse impact on the wheat yield and quality. To date, no measure ensures a complete protection of wheat crops, but the combination of multiple protection measures may produce the promising results. The effectiveness of each measure is influenced by environmental conditions during the growing season and cultivar susceptibility to the FHB. The Integrated Pest Management (IPM) is the most effective approach to the management of FHB. For a successful control, it is essential to acquire a good knowledge of the pathogen, its life cycle, and its ecology. Since the F. graminearum is a predominant species causing the FHB on the wheat in Croatia, this paper aims to describe all available measures for its control.
During cultivation, wheat is exposed to several abiotic and/or biotic stress conditions that may adversely impact the wheat yield and quality. The impact of abiotic stress caused by nitrogen ...deficiency and biotic stress caused by phytopathogenic fungus Fusarium culmorum on biomarkers of oxidative stress in the flag leaf of nine winter wheat varieties (Ficko, U-1, Galloper, BC Mandica, BC Opsesija, Ingenio, Isengrain, Felix, and Bezostaya-1) was analyzed in this study. Hydrogen peroxide concentration and lipid peroxidation level were measured as indicators of oxidative stress, while the antioxidant response was determined by measuring the concentration of phenolic compounds and activities of antioxidant enzymes. Wheat variety and nitrogen treatment had a significant effect on all examined biomarkers of oxidative stress in the flag leaf, while the impact of Fusarium treatment was less pronounced. The most significant impact on the measured stress biomarkers had a low nitrogen level, which mainly increased hydrogen peroxide concentration and lipid peroxidation level and decreased activities of antioxidant enzymes in most varieties. The obtained results were discussed and compared with the previous study in which biochemical analyzes were performed on the wheat spike. There was no significant strong correlation between flag leaf and spike response in the measured parameters, which, in addition to the variety-specific response, also indicates a tissue-specific antioxidant response.
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