N Partitioning between Gluten Fractions in a Set of Italian Durum Wheat Cultivars: Role of the Grain N Content

Abstract

Grain protein content constitutes a key quality trait for durum wheat end-products and may also impact grain protein composition. A total of sixteen durum wheat cultivars were analyzed in a field trial during two seasons at two nitrogen (N) levels to evaluate whether and to what extent the variation in total grain N was associated with variation in the quantity of the various protein fractions and grain quality parameters. Genotypic variation in grain N content correlated with the variation in the content of all three protein fractions, although the strength of the correlation with gliadin and albumin-globulin was higher than that with glutenins. Genotypic variation in gliadin and glutenin content was more tightly correlated with the variation in the sulfur (S)-rich protein groups than with the S-poor protein groups and subunits. The variation in the percentage of unextractable polymeric proteins (UPP%) among genotypes was independent of their glutenin allelic composition. The significant genotypic differences in UPP% and in the ratios between protein groups and subunits were not influenced by the corresponding variation in grain N content. The final grain N content can only account for part of the variation in quality parameters and in the partitioning of total grain N between protein fractions since genotypic differences other than grain N content also contribute to these variations.

Suitability of Improved and Ancient Italian Wheat for Bread-Making: A Holistic Approach

“…This can be useful in future breeding programs for selecting genotypes with high glutenin contents. The values of the GLIGLU are much higher than those found in Tunisian old durum wheat genotypes (0.4–1.16) [ 37 ] and lower than in old Italian durum wheat varieties [ 6 ]. TheGLIGLU ratio is directly associated with bread quality.…”

“…The values of protein content were found within the same range of a study focusing on a set of old Italian durum [ 4 ] but were lower than the values found in a previous study focused on einkorn wheat [ 34 ]. This variability could be due to differences in the conditions of the environment [ 6 , 35 ]. The carbohydrate content was within the same range as the previous study [ 36 , 37 ].…”

“…Our results of glutenin are lower than the ones found in the old, intermediate, and modern durum varieties of the previous study [ 42 ]. The discrepancy in the results could be associated with genetic (a different set of cultivars) and environmental (rainfall and temperature) differences [ 6 ]. Cappelli, Khorasan, and Padre Pio had a high gliadin content and a low glutenin content, leading to a high GLIGLU, while Giovanni Paolo and Garfagnana had a low gliadin content and high glutenin content, leading to a low GLIGLU.…”

“…Breeders are reusing the heterogeneous ancient grains, landraces, and old genotypes to exploit them as a source of genetic diversity for the identification of favorable alleles and to preserve natural agrobiodiversity [ 1 , 3 , 4 , 5 ]. Ancient grains are also known for their high adaptability to harsh conditions, such as marginal areas, low agronomic input, and organic farming [ 2 , 6 , 7 ]. These grains were reported to be sources of proteins, minerals, carotenoids, and polyphenols [ 8 , 9 , 10 ].…”

The end-use quality of wheat can be enhanced by optimal water management without incurring yield loss

“…GN is a reliable indicator of dough elasticity and can be used to determine the proportional composition of grain proteins ( Martre et al., 2003 ; Ferrise et al., 2015 ; Mefleh et al., 2020 ; Snowdon et al., 2021 ). Consequently, changing GN will inevitably modify the proportional composition of grain proteins, which is determined by the “allometric scaling” relationships among the protein compositions.…”