Prospects of GWAS and predictive breeding for European winter wheat’s grain protein content, grain starch content, and grain hardness

Abstract

Grain quality traits determine the classification of registered wheat ( Triticum aestivum L.) varieties. Although environmental factors and crop management practices exert a considerable influence on wheat quality traits, a significant proportion of the variance is attributed to the genetic factors. To identify the underlying genetic factors of wheat quality parameters viz., grain protein content (GPC), grain starch content (GSC), and grain hardness (GH), we evaluated 372 diverse European wheat varieties in replicated field trials in up to eight environments. We observed that all of the investigated traits hold a wide and significant genetic variation, and a significant negative correlation exists between GPC and GSC plus grain yield. Our association analyses based on 26,694 high-quality single nucleotide polymorphic markers revealed a strong quantitative genetic nature of GPC and GSC with associations on groups 2, 3, and 6 chromosomes. The identification of known Puroindoline-b gene for GH provided a positive analytic proof for our studies. We report that a locus QGpc.ipk-6A controls both GPC and GSC with opposite allelic effects. Based on wheat's reference and pan-genome sequences, the physical characterization of two loci viz., QGpc.ipk-2B and QGpc.ipk-6A facilitated the identification of the candidate genes for GPC. Furthermore, by exploiting additive and epistatic interactions of loci, we evaluated the prospects of predictive breeding for the investigated traits that suggested its efficient use in the breeding programs.

Characterization of 150 Wheat Cultivars by LC-MS-Based Label-Free Quantitative Proteomics Unravels Possibilities to Design Wheat Better for Baking Quality and Human Health

“…Protein contents in wheat grains depend on the chosen cultivar due to significant genetic variations [1], to contrasting fertilizer management and to environmental factors such as soil, rainfall and temperature, all affecting the nutrients uptake [2][3][4]. Furthermore, the grain protein content is negatively correlated with grain yield and grain starch content [5]. On average, wheat grain has a protein content of 8-13% [6], which is contributed by water/salt-soluble albumins and globulins (15-20%) and gluten proteins (80-85%), the latter serving as storage proteins and endowing wheat products with the desired viscoelastic and gustatory properties [7][8][9].…”

Novel Loci for Kernel Hardness Appeared as a Response to Heat and Combined Heat-Drought Conditions in Wheat Harboring Aegilops tauschii Diversity

“…The world wheat trade is largely carried out based on hardness grades. Wheat hardness is a quantitative trait with classes ranging from soft to hard [1]. Two genes mainly determine hardness, puroindoline a and b (Pina and Pinb), which are located on the short arm of chromosome 5D (5DS) and form the molecular basis of wheat hardness [2].…”

“…In addition to the puroindoline genes, several studies have identified alleles that contribute to hardness; these were located on most of the 21 wheat chromosomes, but especially on chromosomes 1B, 2A, 4B, 5A, 5B, 5D, and 7D [1,[13][14][15]. Several researchers studied the hardness of plants grown under stress condition [16,17].…”

Protein turnover in the developing Triticum aestivum grain

“…Protein turnover rates and ATP energy cost calculation. Protein synthesis rates and degradation rates were calculated using formulas as follows equation ( 4) equation (5) Where A is the protein starting abundance at the beginning of the labelling programme (7DPA).…”

“…Although global wheat production continues to grow steadily, it is not sufficient to meet predicted demand, especially when the global population is projected to exceed 9 billion by 2050 requiring an increase of wheat production by about 70% 2,3 . To cope with such a challenge, researchers, breeders and wheat-processing industries have been working collaboratively to enhance yield while still maintaining grain-quality attributes such as grain protein content 4,5 .…”