The impact of Septoria tritici blotch in bread making quality among argentinean wheat cultivars

Abstract

Septoria tritici blotch (STB), caused by Zymoseptoria tritici is a relevant foliar wheat disease worldwide. Several reports show the importance of STB on grain yield, their components and grain protein while little is known about its effect on the rheological properties of the wheat flour. The scarce literature found, only mentions the effect of the complex of foliar diseases on wheat quality, without individualizing the effect of the different pathogens separately. This study analyze the influence of increasing doses of inoculum of Zymoseptoria tritici, on the bread making quality of ten Argentinean wheat cultivars and its possible variation according to their quality group. The increase of inoculum concentration augmented the area under disease progress curve, decreased green flag leaf area duration and green leaf area duration. Cultivars K. Flecha and B.75 Aniversario had the lowest green flag leaf area duration causing higher reduction in grain filling period and higher reductions in P, indicating a lower gliadin/ glutenin ratio. STB decreased P/L and E while L, W, D, SV and bread volume increased. Cultivars differed in rheological parameters according to their quality group. Gluten/protein relationship was significant in quality group 1 and non-significant in cultivars belonging to quality group 2 and 3.

How Foliar Fungal Diseases Affect Nitrogen Dynamics, Milling, and End-Use Quality of Wheat

“…As other pathogens Z. tritici infections reduce the grain-filling development (Dimmock and Gooding, 2002b;Pepler et al, 2006); hence there might be proportionally more gliadins, as glutenins are the most affected and the gliadin/glutenin ratio increases, affecting the rheological properties (Stone and Savin, 1999). Related to this, Castro and Simón (2017) found that cultivars with the lowest flag leaf green area duration showed the highest decrease in AlvP and the highest AlvL, AlvW, and loaf volume values when affected by Z. tritici, which can be associated with a high gliadin/glutenin ratio.…”

“…Aside from the effects on the GPC, the gliadin/glutenin ratio could affect the impact of the diseases on the rheological properties. Cultivars with the lowest flag leaf green area duration showed the highest decrease of AlvP and the highest AlvL, AlvW, and loaf volume values (Castro and Simón, 2017) when affected by Z. tritici, which can be related to the gliadin/glutenin ratio. As mentioned previously, these proteins accumulate in the grain asynchronously influencing dough rheological properties (Stone and Savin, 1999) and ultimately bread-making quality.…”

“…This allows expanding the control of pathogens and reducing the possibility of resistance development. In recent years more experiments have been carried out using ecophysiological approaches to analyze the impact of foliar diseases on wheat growth according to its nutritional habit (Serrago et al, 2009;Schierenbeck et al, 2016) and its consequences in yield and/or N dynamics and enduse quality (Castro and Simón, 2017;Fleitas et al, 2018a,b;Schierenbeck et al, 2019a).…”

“…Thus, increases or no effect of Z. tritici in AlvW with the use of fungicides containing triazole-strobilurin have been reported. Discrepancies were also found for the AlvL and the AlvP/L ratio (Cátedra-Cerón and Solís Martel, 2003;Castro and Simón, 2017). Differences between experiments may be partly due to the effect of several pathogens affecting breadmaking quality at the same time under natural infections, in addition to the different bread-making aptitude of the genotypes.…”

“…Differences between experiments may be partly due to the effect of several pathogens affecting breadmaking quality at the same time under natural infections, in addition to the different bread-making aptitude of the genotypes. It has been reported that GPC increases in those cultivars with high bread-making quality (i.e., suitable for leavenedbread production) but tends to decrease in those cultivars with poor bread-making quality (Dimmock and Gooding, 2002c;Castro and Simón, 2017). The protein quality (gliadin/glutenin ratio) is essentially determined by the genotype.…”