Barley and oat have been promoted for years as good sources of dietary fiber, especially ?-glucan. Studies have shown a positive effect of barley and oat ?-glucan on human health and as a result, there has been an increasing demand for ?-glucans in the past decade. Thus, the variability of the ?-glucan content was investigated in the grain of 10 barley and 10 oat varieties. The ?-glucan contents were determined by the ICC Standard Method No 168. The content of ?-glucan in the analyzed barley varieties were within the range 3.52?7.81% and in analyzed oat varieties, the content of ?-glucan were within the range of 3.15?7.28%. Among analyzed barley varieties, Novosadski 314 contained the highest content of ?-glucan (7.81%), while Tomba had the highest content of ?-glucan (7.28%) in the analyzed oat varieties. Based on the results, it could be concluded that there is genetic diversity of oat and barley varieties with respect to their ?-glucan content. This fact enables varieties with a high a nutritional capacity to be selected.

Proline is one of the organic osmolytes that accumulates in plants in response to stressful environmental conditions. The aim of this study was to determine the concentration of proline in the grain filling phase in ten winter wheat cultivars under conditions of prolonged periods of air temperatures above 30?C and to assess the variability of wheat variety responses. The correlation between proline accumulation and photosynthetic pigments, accumulated starch and yield was also determined. In the experimental field, flag leaves were sampled for each variety in the grain filling phase. Statistical data analysis and parameter correlation were performed using the SPSS program. The results showed that there is a statistically significant difference between proline values in moderate and high air temperature conditions when proline accumulation occurs. The significant correlation of accumulated starch content and yield with proline concentration showed that in addition to higher proline values under heat stress, wheat varieties Apac, Talas and Futura also have higher yield and starch content. A correlation was also found between proline concentration and photosynthetic pigment contents, where the Apac wheat variety showed the best adaptive response to the investigated traits and was characterized by a smaller reduction in photosynthetic pigment content under heat stress. The interrelation of proline with the photosynthetic pigment content and wheat quality parameters may be important in breeding technologies aimed at improving wheat stress tolerance.

Heat stress has a significant effect on the growth and development of cereals and affects cereals production by reducing the total yield. High temperatures in plants lead to oxidative stress, which creates reactive oxygen species that are specific to cause damage to the cell membrane. Due to the action of reactive oxygen species, lipid peroxidation can occur. For that reason, it is important to find cultivars that are more resistant to the harmful effects of heat stress and thus enable higher productivity. The aim of this study was to determine the effect of heat stress on the degree of lipid peroxidation and yield elements in leaves of 10 wheat cultivars, in order to select cultivars more resistant to heat stress. The degree of lipid peroxidation was determined spectrophotometrically by measuring the concentration of reactive substances of thiobarbiturate acid (mainly malondialdehyde - MDA). The cultivar Renesansa with the largest increase in MDA in conditions of high air temperature (2.848 µmol/g fw) was also characterized by the lowest yield (2870 kg/ha). On the other hand, the cultivar Talas with the smallest increase in MDA content (1800 µmol/g fw) in conditions of high air temperature showed significantly higher yield (3830 kg/ha). In this paper was shown that lipid peroxidation has a significant effect on yield reduction in the investigated wheat cultivars. Cultivars Talas, Apač, Hyfi, Mila and Salasar were characterized as cultivars more resistant to heat stress with higher yields. These results suggest that wheat cultivars were significantly different in their ability to respond to heat stress, which could be useful for the development of tolerant wheat cultivars in the breeding programs.

Barley is an important source of b-glucans because they have a positive influence on human health and potential application in the food industry. The aim of this manuscript was to determine the variability of ten barley cultivars based on b-glucan content. The percentage of b-glucan varied in the range of 4.44% to 8.17%, with a mean value of 6.57%. Based on b-glucan content, the degree of cultivar similarity was determined by the dendrogram. Among analyzed barley cultivars, the highest concentration of b-glucan was found in the cultivar Lav and Ukras, while the lowest concentration was observed in the cultivar Vihor (4.44%). Compared with all the other cultivars mentioned, a pair of cultivars expressed the greatest distance. Statistical analysis showed that there is a significant difference between analyzed barley cultivars. The analysis of b-glucans in varieties of barley in two growing seasons aims to develop an agricultural strategy and develop barley varieties with higher b-glucans content.