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Due to climate change, multiple heat events are expected to be an additional limiting factor that will adversely affect wheat production. The study aimed to analyze the physiological response to heat stress in four winter wheat cultivars at different physiological stages under greenhouse conditions during 2019. The net photosynthetic rate, stomatal conductance, chlorophyll index, maximum quantum efficiency of photosystem II, fructose, glucose and sucrose content, grain yield per plant, grain weight and number of grains per plant were analyzed in wheat cultivars under short periods of heat stress at anthesis and mid‐grain filling, and combined stress at anthesis and mid‐grain filling. The results of the study indicated that heat stress modified the photosynthesis‐related and grain yield–related traits. Moreover, heat stress caused a decrease of sucrose content, while fructose and glucose content increased. Heat stress had more pronounced effects on the photosynthetic parameters and grain yield during grain filling than during anthesis. A significant variation observed among cultivar responses to the negative impact of heat stress highlighted the fact that cultivars Pobeda and Gladius were more tolerant than Renesansa and Simonida. Different cultivar reactions to heat stress during anthesis and grain filling indicated the need to conduct further studies with wheat cultivars of different origin in order to identify additional sources of tolerance.

Analyzing 167 non-processed seed samples of wheat, it was found that 145 samples (86.8 %) were contaminated with Tilletia species, while 22 (13.2 %) samples were not contaminated. By using rep-PCR fingerprinting technique, it was found that DNA isolates of T. tritici originated from Serbian wheat samples had 80 % similarity with positive control for T. tritici. One isolate shared similarity of 60% with T. tritici, T. controversa and T. laevis. It was supposed that this isolate belongs to T. bromi. Isolate of T. laevis shared a similarity of 70 % with isolates of T. tritici and T. controversa, while T. walkeri was more than 10 % similar with T. tritici, T. controversa and T. laevis. Although T. controversa and T. tritici had high percent of genetic similarity, they were clustered separately. Our results suggest that rep-PCR fingerprinting could be a useful tool for monitoring presence of morphologically similar Tilletia species in wheat production areas

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The importance of uniform germination and field emergence for achieving high yields, while ensuring good seed quality, raises the question of the influence of fungicide and insecticide preparations for seed treatment. The aim of this study was to determine the effect of the combination of five insecticides and fungicide preparations on germination energy and germination of four maize inbred lines. The impact of applied preparations on seed quality may vary, depending on the genetic composition of maize inbred lines. Inbred line L-1 was distinguished as the most tolerant, considering the fact that significant differences were not observed in all tested preparations, while the most sensitive genotype, inbred line L-4, showed a significant decrease in germination energy and seed germination when treated with fludioxonil+metalaxyl-M (M), fludioxonil+metalaxyl-M and imidacloprid (M+G), fludioxonil+metalaxyl-M and thiametoxam (M+Cr) and fludioxonil+metalaxyl-M and tefluthrin+thiametoxam (M+FZ). Results of this study indicate the importance of choosing the best combination of pesticides for certain genotypes, in order to ensure full protection of crops and at the same time obtain the high yields.

Advantages or disadvantages of intercropping system can estimate through expression of components of yield on the base of values of productive organs (spike, pod). The aim of this work was study of variation of spike index in cereals species and pods index in pea of spring intercropping. For investigation included spring species of small grains: wheat, triticale, oat and spring legume pea. The investigation was carried out in field condition in experiment with randomised block design of 5m 2 plots, with 4 replications. Each species (cereals and pea) were sown sole and in intercrops wheat+pea, triticale+pea and oat+pea. At the maturity stage used 40

Monitoring changes in the prevalence of Fusarium species and toxin production is an important tool for the integrated control of Fusarium head blight (FHB). However, methods for the high-throughput screening of Fusarium populations have been developed using isolates with limited geographic origins. In this study, we used species- and trichothecene-specific primers to monitor the F. graminearum species complex (FGSC) originating from Serbia. We also tested the applicability of the primers to the surveillance of FHB. We analyzed two hundred and ten isolates collected from thirty two locations and five winter wheat varieties over a three-year period. Using multiple correspondence analysis (MCA), we investigated associations between Fusarium-damaged kernels (FDK) and location, variety, members of the FGSC, and their predisposition for mycotoxin production. The results revealed that the species-specific primers were not specific for 11% of the F. graminearum population. The primer sets were 98.5%, 95.2%, and 92.4% effective in the multilocus genotyping of Tri7, Tri3, and Tri5 genes, respectively. We found that individual wheat varieties were associated with isolates that could not be characterized using species- and trichothecene-specific primers. Alternaria spp. had a significant influence (p < 0.001) on grain infection with F. graminearum, indicating the necessity to further investigate its impact on the pathogenesis of the F. graminearum clade.

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