Genetic analyses and association mapping were performed on a winter wheat core collection of 96 accessions sampled from a variety of geographic origins. Twenty-four agronomic traits were evaluated over 3 years under fully irrigated, rainfed and drought treatments. Grain yield was the most sensitive trait to water deficit and was highly correlated with above-ground biomass per plant and number of kernels per m2. The germplasm was structured into four subpopulations. The association of 46 SSR loci distributed throughout the wheat genome with yield and agronomic traits was analyzed using a general linear model, where subpopulation information was used to control false-positive or spurious marker-trait associations (MTAs). A total of 26, 21 and 29 significant (P < 0.001) MTAs were identified in irrigated, rainfed and drought treatments, respectively. The marker effects ranged from 14.0 to 50.8%. Combined across all treatments, 34 significant (P < 0.001) MTAs were identified with nine markers, and R2 ranged from 14.5 to 50.2%. Marker psp3200 (6DS) and particularly gwm484 (2DS) were associated with many significant MTAs in each treatment and explained the greatest proportion of phenotypic variation. Although we were not able to recognize any marker related to grain yield under drought stress, a number of MTAs associated with developmental and agronomic traits highly correlated with grain yield under drought were identified.

Landraces of wheat (Triticum aestivum L.), collected from the Western Balkans, were considered as a potential genetic resource of drought resistance for wheat breeding. A group of 20 landraces with 80 wheat accessions of worldwide origin were tested in 4-year field trials under two watering regimes: fully irrigated and under a rain-out plot shelter. Fourteen agronomic traits were evaluated for their responses to drought stress, and four selection indices were calculated: mean productivity (MP), stress tolerance (TOL), stress susceptibility index (SSI) and stress tolerance index (STI). The average yield of landraces was significantly lower than that of accessions under both regimes, and there was no evidence that yield stability of landraces was better than that of accessions. However, TOL was better in landraces than in accessions, and several traits related to yield were shown to suffer less under water deficit (i.e. kernels per spike). Amongst landraces, relatively wide diversity (CV 10.2-18.9%) was found for most of the traits that can be exploited for improving drought tolerance of new varieties for the variable rainfed conditions of south-eastern Europe.

The correlation analysis and the path coefficient analysis were applied to wheat data set with the objective to determine the effect of five physiological traits (early vigor, early maturity, leaf senescence, flag leaf area and total biomass per plant) on grain yield under irrigation and drought stress conditions. The data set consisted of 100 divergent genotypes tested in four-year field trials. Highly significant correlations were found between grain yield, early vigor and total biomass per plant in both treatments. A highly negative correlation was detected between grain yield and days to flowering, as well as, between grain yield and leaf senescence in both treatments. The path analysis revealed a highly significant direct effect of days to anthesis and total biomass per plant on grain yield. Early vigor, leaf senescence and the flag leaf area had a significant indirect effect on grain yield via days to anthesis and total biomass per plant. Early vigor, early maturity and leaf senescence were found to be suitable for wheat breeding under different moisture regimes. These traits can be evaluated quickly and easily, and thus they can be used for the evaluation of large populations

Improving resistance to water and osmotic stresses at the seedling stage is becoming a much more important target for wheat breeders due to an increase in the frequency and severity of drought occurrences at the crop establishment and tillering phases in many wheat growing areas of the world. Ninety-six diverse wheat genotypes were laboratory tested for germination and growth response under osmotic stress induced by polyethylene glycol (PEG). Germination percentage, mean germination time, coleoptile length, shoot length and shoot growth rate were compared under stress (− 0·4 MPa) and control (0·0 MPa) conditions. The same genotypes were previously grown in field trials exposed to drought stress during the anthesis and/or grain filling growth stage along with control (optimum) conditions. Grain yield (GY) and 19 other traits of agronomic importance (earliness, stemrelated traits, number of kernels, mass of 1000 grains, etc.) were recorded. All seedling traits under PEG-induced water stress showed the highest relationship with the stem and stem-related traits of adult plants. To study the correlation between stress tolerance in the seedling and reproductive stages, three stress indices (tolerance index (TOL), stress susceptibility index (SSI) and stress tolerance index (STI)) for the seedling traits and GY under pre-and post-anthesis drought stress were calculated, based on a mean trait value obtained under stress and the corresponding trait value under control conditions. The ranking of the genotypes based on TOL and STI from seedling traits was found in most cases to be significantly correlated with the ranking of genotypes based on TOL and STI from GY, respectively.

When water stress develops post-anthesis, wheat (Triticum aestivum L.) plants have to rely increasingly on remobilization of previously stored assimilates to maintain grain filling. In two-year field trials, we studied more than 20 agronomic and developmental traits in 61 wheat genotypes (27 F4:5 families, 17 parents used for the crosses and 17 standards), comparing plants that were defoliated (DP) by cutting off all leaf blades 10 days after anthesis with intact control plants (CP). Estimated contributions of stem and sheath assimilate reserves to grain weight/spike were from 10-54% and from 24-84% in CP and DP plants, respectively. Stem-related traits were among key traits determining stem reserve contribution (SRC). The most important genetic variables in differentiating genotypes for stress tolerance were biomass/stem, stem reserves mobilization efficiency and grain filling rate (GFR). Balance among traits related to yield maintenance in DP were more important than their high values. In general F4:5 families (FAM), that had been crossed to combine typical breeding traits such as biomass and yield components, showed better tolerance under moderate stress than standards and parents.

Proteins are important in determining the nutritional value of wheat, and among them gluten determines the baking quality of bread wheat and pasta-making technological properties of wheat. By assessing genetic parameters of wheat quality traits, it is possible to elucidate potential for improvement. The plant material consisted of 30 genotypes of bread and durum wheat of worldwide origin. The trials were sown at three locations in Serbia during two vegetation seasons 2010-2011 and 2011-2012. Protein content, wet gluten content, Zeleny sedimentation volume and deformation energy were determined by near infrared spectrometry. The objectives of this investigation were to assess: i) variability, components of variance, heritability in a broad sense , expected genetic advance for protein content, wet gluten content, Zeleny sedimentation volume and deformation energy; ii) associations between agronomic characteristics and protein content, wet gluten content, Zeleny sedimentation volume and deformation energy in order to determine indirect selection feasibility. In durum wheat, the highest coefficients of genetic and phenotypic variation (CV g and CV ph ) were recorded for deformation energy in bread wheat (18% and 18.4%, respectively), whereas the lowest values of 4.1% and 4.6% were shown for protein content. The relation genetic component of variance ( ) / component of variance due to genotype × environment interaction ( ) > 1 was observed for protein content (3.2), wet gluten content (2.9) and deformation energy (3.9), and equal to one for Zeleny sedimentation volume, in bread wheat. In durum wheat, / > 1 was detected for protein content (1.4), wet gluten content (1.5), Zeleny sedimentation volume (2.1) and deformation energy (1.4). Considering very high and high observed for deformation energy and Zeleny sedimentation volume (95.8% and 86.2%, respectively) in bread wheat, coupled with high genetic advance (36.3% and 28.1%, respectively), success from classical breeding can be anticipated. Grain thickness was strongly associated with Zeleny sedimentation volume, and to a lesser extent with protein content, wet gluten content and deformation energy in bread and durum wheat, and along with grain vitreousness in durum wheat, can serve for indirect selection.Key words: common wheat and durum wheat, expected genetic advance, gluten strength, proteins, wet gluten, Zeleny sedimentation volume.Please use the following format when citing the article: Branković G., Dodig D

Small grain cereals in lower latitude areas usually mature under terminal drought conditions that affect their agronomic performance. An experiment was conducted to compare agronomic traits, grain yield, and protein content under control and terminal drought conditions of 15 two-row and 10 six-row barley (Hordeum vulgare L.) genotypes. The experiment was set up at two locations for two growing seasons (2011, 2012) and two treatments. One treatment was terminal drought (D) simulated by the mechanical removal of all leaf blades 7 d after the heading of each genotype, and a control (C) treatment in which plants were left intact. On average, defoliation caused a greater reduction in grain yield and protein content of the six-row genotypes (37.6% and 12.3%, respectively) than the two-row genotypes (28.8% and 7.1%, respectively). On the other hand, test weight of six-row genotypes showed better tolerance to terminal drought. According to the multivariate function analysis, the genotypes of both types of barley with a high test weight, a longer uppermost internode, and a longer grain filling period had high protein content under terminal drought stress. In contrast to six-row genotypes, it is possible to breed two-row genotypes that not only have high grain yield but also high protein content under both optimal and drought stress conditions.

Summary The aim of this study was to compare five bread and five durum wheat genotypes for gliadins and glutenins profiles, the concentration of free sulphhydryl groups and disulphide bonds, antioxidant capacity of gluten proteins and their bread‐making performance. On average, bread wheat had significantly higher concentration of total sulphur‐rich (S‐rich) and sulphur‐poor (S‐poor) subunits of gliadins, as well as total low molecular weight (LMW) and high molecular weight (HMW) subunits of glutenins than durum wheat. However, durum wheat had higher concentration of S‐rich γ‐gliadins and S‐poor D‐LMW‐glutenins, but did not possess S‐poor ω‐gliadins. The concentration of disulphide bonds and total cysteine was higher in the durum gluten than that in the bread gluten, as well as antioxidant capacity (on average 90.6 vs. 85.9 mmol Trolox Eq kg−1, respectively). In contrast to the bread wheat, the concentration of HMW‐glutenins was negatively associated with extensibility, as well as resistance to extension in durum wheat flour dough.