Durum Wheat Grain Yield and Quality under Low and High Nitrogen Conditions: Insights into Natural Variation in Low- and High-Yielding Genotypes

Starch and storage protein dynamics in the developing and matured grains of durum wheat and diploid progenitor species

Durum wheat, less immunogenically intolerant than bread wheat, originates from diploid progenitors known for nutritional quality and stress tolerance. Present study involves the analysis of major grain parameters, viz. size, weight, sugar, starch, and protein content of Triticum durum (AABB genome) and its diploid progenitors, Triticum monococcum (AA genome) and Aegilops speltoides (BB genome). Samples were collected during 2-5 weeks after anthesis (WAA), and at maturity. The investigation revealed that T. durum displayed the maximum grain size and weight. Expression analysis of Grain Weight 2 (GW2) and Glutamine Synthase (GS2), negative and positive regulators of grain weight and size, respectively, revealed higher GW2 expression in Ae. speltoides and higher GS2 expression in T. durum. Further we explored total starch, sugar and protein content, observing higher levels of starch and sugar in durum wheat while AA genome species exhibited higher protein content dominated by the fractions of albumin/globulin. HPLC profiling revealed unique sub-fractions in all three genome species. Additionally, a comparative transcriptome analysis also corroborated with the starch and protein content in the grains. This study provides valuable insights into the genetic and biochemical distinctions among durum wheat and its diploid progenitors, offering a foundation for their nutritional composition.

Effect of Fertilization Regime of Common Wheat (Triticum aestivum) on Flour Quality and Shelf-Life of PDO Tuscan Bread

The shelf-life of bread is influenced by flour components, such as starch, composed of amylose and amylopectin. The aim was to test the effect of different balances of N (45, 90, 135 kg/ha) and P (48, 96 kg/ha) fertilizers on the flour characteristics and consequently the shelf-life of PDO Tuscan bread, stored in different modified atmosphere packaging (Ar, N₂, Air). The amylose and phytochemical compounds were increased by N and decreased by the addition of P, but excessive doses of N (135 kg/ha) had a negative effect on flour quality. In the bread, the study highlighted the tendency of N₂ and Ar, as storage filler gases, to reduce water loss, slow down the staling process, and prolong shelf-life. However, the most significant influence on shelf-life was related to the different fertilizations of wheat. In fact, when N was present in equal dose to P (90/96 or 45/48 kg/ha) or slightly higher (90/48 kg/ha), the bread tended to last longer over time. Instead, when these ratios were unbalanced in favor of N (135/48 or 135/96 kg/ha) and in favor of P (45/96 kg/ha), the shelf-life decreased considerably.

Factors Affecting the Nutritional, Health, and Technological Quality of Durum Wheat for Pasta-Making: A Systematic Literature Review

Durum wheat is one of the most important food sources in the world, playing a key role in human nutrition, as well as in the economy of the different countries in which its production areas are concentrated. Its grain also represents a staple and highly versatile ingredient in the development of health foods. Nonetheless, the aspects determining durum wheat's health quality and their interactions are many, complex, and not entirely known. Therefore, the present systematic literature review aims at advancing the understanding of the relationships among nutritional, health, and technological properties of durum wheat grain, semolina, and pasta, by evaluating the factors that, either positively or negatively, can affect the quality of the products. Scopus, Science Direct, and Web of Science databases were systematically searched utilising sets of keywords following the PRISMA guidelines, and the relevant results of the definitive 154 eligible studies were presented and discussed. Thus, the review identified the most promising strategies to improve durum wheat quality and highlighted the importance of adopting multidisciplinary approaches for such purposes.

Effect of Production Technology Intensity on the Grain Yield, Protein Content and Amino Acid Profile in Common and Durum Wheat Grain

Products derived from wheat grains are an important source of protein in the daily diet of people in many parts of the world. The biological value of protein is determined by its amino acid composition and the proportions of the individual amino acids. Synthesis of these compounds in wheat grains is influenced by genetic factors, as well as habitat conditions and the agrotechnology applied in cultivation. The aim of this study was to assess the effect of production technology (integrated, intensive) on the grain yield and the content amino acid profile of protein in common and durum wheat grain. Field research was conducted at the Experimental Station IUNG-PIB in Osiny (Poland) in two growing seasons. It was found that grain yield significantly depended on the weather conditions in the years of harvesting and genotype, but did not depend on the production technology. On the other hand, the protein content and their amino acid composition depended significantly on the production technology and genotype. A significantly higher content of protein substances was found in durum wheat grain. Increasing the intensity of production technology had a positive effect on the total protein content and the content of individual amino acids, both exogenous and endogenous. The amino acid limiting the biological value of protein contained in grains of both wheat species was lysine, and the deficiency of this amino acid was significantly lower in grain protein from intensive than integrated cultivation technology.

Genotypic and Environmental Effects on Morpho-Physiological and Agronomic Performances of a Tomato Diversity Panel in Relation to Nitrogen and Water Stress Under Organic Farming

The agricultural scenario of the upcoming decades will face major challenges for the increased and sustainable agricultural production and the optimization of the efficiency of water and fertilizer inputs. Considering the current and foreseen water scarcity in several marginal and arid areas and the need for a more sustainable farming production, the selection and development of cultivars suitable to grow under low-input conditions is an urgent need. In this study, we assayed 42 tomato genotypes for thirty-two morpho-physiological and agronomic traits related to plant, fruit, and root characteristics under standard (control) and no-nitrogen fertilization or water deficit (30% of the amount given to non-stressed trials) treatments in two sites (environments), which corresponded to organic farms located in Italy and Spain. A broad range of variation was found for all traits, with significant differences between the applied treatments and the cultivation sites. Dissection of genotypic (G), environmental (E), and treatment (T) factors revealed that the three main factors were highly significant for many traits, although G was the main source of variation in most cases. G × E interactions were also important, while G × T and E × T were less relevant. Only fruit weight and blossom end rot were highly significant for the triple interaction (G × E × T). Reduction of water supply significantly increased the soluble solid content in both locations, whereas both nitrogen and water stress led to a general decrease in fruit weight and total yield. Despite so, several accessions exhibited better performances than the control when cultivated under stress. Among the accessions evaluated, hybrids were promising in terms of yield performance, while overall landraces and heirlooms exhibited a better quality. This suggests the possibility of exploiting both the variation within ancient varieties and the heterosis for yield of hybrids to select and breed new varieties with better adaptation to organic farming conditions, both under optimal and suboptimal conditions. The results shed light on the strategies to develop novel varieties for organic farming, giving hints into the management of inputs to adopt for a more sustainable tomato cultivation.

Preharvest phenotypic prediction of grain quality and yield of durum wheat using multispectral imaging

Durum wheat is an important cereal that is widely grown in the Mediterranean basin. In addition to high yield, grain quality traits are of high importance for farmers. The strong influence of climatic conditions makes the improvement of grain quality traits, like protein content, vitreousness, and test weight, a challenging task. Evaluation of quality traits post-harvest is time- and labor-intensive and requires expensive equipment, such as near-infrared spectroscopes or hyperspectral imagers. Predicting not only yield but also important quality traits in the field before harvest is of high value for breeders aiming to optimize resource allocation. Implementation of efficient approaches for trait prediction, such as the use of high-resolution spectral data acquired by a multispectral camera mounted on unmanned aerial vehicles (UAVs), needs to be explored. In this study, we have acquired multispectral image data with an 11-band multispectral camera mounted on a UAV and analyzed the data with machine learning (ML) models to predict grain yield and important quality traits in breeding micro-plots. Combining 11-band multispectral data for 34 cultivars and 16 environments allowed to develop ML models with good prediction capability. Applying the trained models to test sets explained a considerable degree of phenotypic variance with good accuracy showing r squared values of 0.84, 0.69, 0.64, and 0.61 and normalized root mean squared errors of 0.17, 0.07, 0.14, and 0.03 for grain yield, protein content, vitreousness, and test weight, respectively.

Source-Sink Dynamics in Field-Grown Durum Wheat Under Contrasting Nitrogen Supplies: Key Role of Non-Foliar Organs During Grain Filling

The integration of high-throughput phenotyping and metabolic approaches is a suitable strategy to study the genotype-by-environment interaction and identify novel traits for crop improvement from canopy to an organ level. Our aims were to study the phenotypic and metabolic traits that are related to grain yield and quality at canopy and organ levels, with a special focus on source-sink coordination under contrasting N supplies. Four modern durum wheat varieties with contrasting grain yield were grown in field conditions under two N fertilization levels in north-eastern Spain. We evaluated canopy vegetation indices taken throughout the growing season, physiological and metabolic traits in different photosynthetic organs (flag leaf blade, sheath, peduncle, awn, glume, and lemma) at anthesis and mid-grain filling stages, and agronomic and grain quality traits at harvest. Low N supply triggered an imbalance of C and N coordination at the whole plant level, leading to a reduction of grain yield and nutrient composition. The activities of key enzymes in C and N metabolism as well as the levels of photoassimilates showed that each organ plays an important role during grain filling, some with a higher photosynthetic capacity, others for nutrient storage for later stages of grain filling, or N assimilation and recycling. Interestingly, the enzyme activities and sucrose content of the ear organs were positively associated with grain yield and quality, suggesting, together with the regression models using isotope signatures, the potential contribution of these organs during grain filling. This study highlights the use of holistic approaches to the identification of novel targets to improve grain yield and quality in C₃ cereals and the key role of non-foliar organs at late-growth stages.

Normalized Difference Vegetation Index and Chlorophyll Content for Precision Nitrogen Management in Durum Wheat Cultivars under Semi-Arid Conditions

To impart sustainability to modern intensive farming systems, environmental pollution caused by nitrogenous fertilizers in needs to be reduced by optimizing their doses. To estimate the grain yield and nutrtional quallity of wheat, the normalized difference vegetation index (NDVI) and chlorophyll content (SPAD) are potential screening tools to identify the N deficiency and screen out the promising cultivars. The two-year field study was comprised with five levels of nitrogen (N) (control, 50, 100, 150 and 200 kg N ha−1) and two durum wheat genotypes (Sena and Svevo). The experimental design was split-plot, in which N levels were placed in the main plots, while wheat genotypes were arranged in sub-plots. To predict the yield and quality traits, the NDVI and SPAD values recorded at heading, anthesis and milky growth stages were taken as response variables. The results revealed that N fertilization significantly influenced the SPAD and NDVI attributed traits of durum wheat, except NDVI at milky stage (NDVI-M) during the first year. The maximum value of NDVI was recorded by 150 kg N ha−1, while control treatment gave the minimum value. The grain yield was increased with the increasing dose of the N up to 100 kg N ha−1 (4121 kg ha−1), and thereafter, it was declined with further increased of N levels. However, the variation between the genotypes was not significant, except NDVI and SPAD values at the milky stage. The genotype Svevo had the highest NDVI values at all growth stages, while the genotype Sena recorded the maximum SPAD values during both years. Similarly, the N levels significantly influenced the quality traits (protein, wet gluten, starch test weight and Zeleny sedimentation) of both genotypes. The highly significant relationship of SPAD and NDVI with the grain yield and yield attributes showed their reliability as indicators for determining the N deficiency and selection of superior wheat genotypes for ensuring food security under climate change scenario.