The quality of grain means a set of technologico-biochemical, baking and food properties determining the economic value of a grain variety. When choosing source material for selection, the degree of grain preservation in adverse environmental conditions is taken into account as well as the genotypic potential of grain yield and quality. It is believed that in the arid conditions of the Volga region, the main limiting factor in the formation of high-quality grain is the amount of precipitation during the growing season of wheat and the uniformity of its distribution, so more than 25 indices of the winter wheat quality are evaluated annually, including the quantitative expression of indices of the rheological properties of dough. Experimental data indicate that such indices as water absorption capacity (WAC, %); energy absorbed by dough during mixing (W·h/kg); dough stability, (min); dough dilution (C2, N·m); and starch retrogradation index (C5, N·m) provide sufficient information for selection. The dough formation time seems the least promising indicator: genotype-environmental interactions on this index were manifested in 100% of cases. In the process of studying the ball-shaped forms of winter soft wheat it has been revealed that they have a high crop yield and excellent grain quality, namely the dough stability, which is 10.3, 9.9, 9.7, and 8.4 min in the studied samples Nos. 209–212, respectively. They also exceed the Saratov 90 variety by C2 , which characterizes dough dilution, having values of 0.57, 0.52, and 0.47 N·m, while having excellent baking qualities. The variation limits of the index of flour whiteness were 60.5–71.9 in the red-grain group of winter wheat and 57.5–69.6 in the white-grain one. The average value of this index is 66.3 and 57.5, respectively. Extra-quality flour can be obtained from the Smuglianka variety and lines with breeding numbers 17-17, 34-17, 1081-17, 1096-17, and 1093-17. Of all the others, we can get highest-grade flour without exception. The correlation between the indicators of meal whiteness and flour whiteness in the red-grain and white-grain forms of winter wheat is 0.7660 at the 1% significance level and 0.9311, respectively. This means that it is possible to assess the whiteness of flour from the color of whole-milled grain with a high probability.

The purpose of the current work was to study the development of tan spot, the causative agent of yellow leaf spot Pyrenophora tritici-repentis (Died) Drechsler on winter bread wheat in the conditions of the Saratov region of Russia. In 2018–2019 there was carried out an estimation of the resistance of 33 winter bread wheat samples to the causative agent of yellow leaf spot. It was established that the varieties “Gostianum 237” and “Levoberezhnaya 1” were characterized by a high level of resistance in the fields. There were identified such weak susceptible varieties as “Victoria 95”, “Gubernia”, “Mironovskaya 808”, “Donskaya bezostaya”, “Smuglyanka”, “Kalach 60”, “111-96 / Zhemchuzhina Povolzhiya”, “L 329 / Urozhaynaya”, “Gubernia / Zhemchuzhina Povolzhiya”, “Saratovskaya 90/ Ukraina”, “L 503 / M Freeman”, “81-93 / (Saratovskaya 11 / Kharkov 82)”. There was identified a moderate damage in the varieties “Lutenscens 230”, “Saratovskaya 80”, “Saratovskaya 90 / 14431 M”, “Sozvesdie”, “Anastasia”, “Saratovskaya 8 / Yubilyar”. The varieties “Zhemchuzhina Povolzhiya”, “Saratovskaya 17”, “Elvira”, “Saratovskaya 8 / B.Z.D.”, “(26-72 / N 49)/(L 15 / Pia)/Sar. 8)”, “Saratovskaya 8 / Yubilyar”, “L 503 / M Freeman”, “30-99/(Saratovskaya 11 / Kharkovskaya 82)”, “Sharada / L 31-98”, “346-06 / L 1334-5”, “Saratovskaya 90”, “L 329 / Saratovskaya ubileynaya”, “Istok/(Saratovskaya 90 / L 503)”, “Brigantina / Don 74” were found susceptible to the pathogen. It was identified that the proportion of winter soft wheat samples resistant to Pyrenophora tritici-repentis was 42% of the total number of varieties studied. There was studied dynamics of Pyrenophora tritici-repentis development in the winter soft wheat variety “Saratovskaya90”. It was found out that the damage degree of the winter bread wheat variety “Saratovskaya90” greatly depended upon the remoteness of the sowings from the source of infection.

The current paper has presented the study results of collection winter bread wheat samples. The purpose of the study was to screen the world collection of winter bread wheat for disease resistance in the Nizhnevolzhsky region. The study was carried out on the basis of the FSBSI “Federal Agricultural Research Center of the South-East” (Saratov). In 2017–2021 there was conducted an estimation of the resistance of 152 winter bread wheat samples to the main pathogens. The samples were sown at the optimal time with the SSFC-8 seeder on plots of 3 m2 in a single repetition. The seeding rate was 450 germinating seeds per m2 . There have been studied the world collection varietal samples of winter bread wheat VIR (from breeding centers of the USA, Canada, Ukraine, Slovakia, Latvia, Hungary, etc.), as well as the samples of domestic breeding (FANC of the South-East, NTsZ named after P.P. Lukyanenko, Severokavkazsky FNATS, etc.). There have been identified the most harmful leaf-stem diseases, such as brown rust (Puccinia triticina Erikss.) and stem rust (Puccinia graminis f. sp. Tritici), septoria (Septoria tritici Rob. et Desm.) and yellow leaf blotch (Pyrenophora tritici-repentis (Died) Drechsler). There has been characterized the resistance of the winter bread wheat collection to the complex of leaf-stem diseases. There have been identified two samples with group resistance to brown and stem rusts, septoria and pyrenophorosis; one sample resistant to leaf rust and stem rust; three samples resistant to stem rust and septoria; one sample resistant to leaf and stem rust and septoria; six samples resistant to septoria and pyrenophorosis.