Both spring and winter barley were sown after a forecrop of winter rape. Three registered model varieties of six row and two row winter barley reached in the period 1999-2001 significantly higher yield than three model varieties of spring barley. Two row spring and winter varieties produced significantly higher thousand grain weight (TGW) than six row winter barley. The resistance to diseases and lodging (correlation coefficient with resistance to powdery mildew represent 0.68 ** , rust 0.72 ** , lodging 0.61 ** ) was the most important factor determining the yield. Resistance to rust has influenced sieving on 2.5 mm, correlation coefficient reached value 0.88 ** . No significant differences were determined in any malting quality parameter when varieties of two row winter barley variety (Tiffany), and spring barley varieties (Akcent and Tolar) were compared. Variety Tolar reached higher parameters for friability and a beta glucan content. Between years, significant differences were found in following parameters: protein content and apparent degree of attenuation. Due to reduction of area sown with spring barley and reduced yield potential, two row winter barley varieties with comparable malting parameters are recommended to be cultivated as the reserve crop for malting barley industry demands.

485Fusarium head blight (FHB) is a worldwide distributed cereal disease that is caused by fungi of the Fusarium genus. Infection of plants can result in yield reduction and accumulation of toxic secondary fungal metabolites, mycotoxins in kernels (Windels 2000, Takeda 2004). The number of papers dealing with FHB on barley is generally much lower than that of research studies on wheat. It is due to a much greater economic importance of wheat as a cereal crop, but as well as to the fact that FHB causes larger economic losses in wheat than in barley. Though the two crops are attacked by identical FHB pathogens, there are differences in their infection responses. In general, barley is less susceptible to FHB than wheat. Grain yield is affected by FHB more in wheat than in barley, however a higher mycotoxin concentration is observed in the latter due to outer cover layers (lemma and palea) that are parts of the kernel from harvest to end use (Steffenson 2003). Produced toxins are harmful to human health and can induce serious diseases. The mycotoxins are deactivated neither in malting nor in brewing processes. Moreover, they can influence beer flavour and cause gushEvaluation of spring barley genotypes with different susceptibility to Fusarium head blight using molecular markers ABSTRACTOne of cereal diseases that has gained a greater importance for growers, processing industry as well as for breeders in many regions of the world is Fusarium head blight (FHB) caused by fungi of the Fusarium genus. The objectives of this study were to test diversity among spring barley breeding lines exhibiting various sensitivity to FHB and to find RAPD markers and AFLP markers that will distinguish between susceptible and resistant and/or moderately resistant genotypes. A test of a set of spring barley genotypes artificially infected by fusaria in field trials was carried out. Based on the results from field and laboratory evaluation and deoxynivalenol (DON) content assessment, barley genotypes with different responses to FHB were selected. The genotypes were hybridized and doubled haploid (DH) lines were derived in F 1 generation using the in vitro androgenesis method. Initial parental components and derived DH lines were tested for FHB infection and DON content. A set of parental genotypes of spring barley was tested with 80 RAPD markers. A RAPD marker (H30) was detected which enabled to distinguish between very susceptible parental genotypes and other resistant or moderately resistant spring barley genotypes based on the fragment of about 1300 bp. This specific product was screened in 23 DH lines derived from crosses of parental genotypes of spring barley and detected in 10 DH lines. During the study, some DH lines were selected that exhibited improved resistance to Fusarium infection. A low infection level and low DON content was found in the line DH 4/2 derived from CI 4196 × Foster. The AFLP technique was used to analyse parental genotypes of spring barley. The detected markers can be further evaluated and employed to select ...

Rice straw is potentially an appropriate feedstock material for biofuel production, since a huge amount of this postharvest residue is generated every year. The transformation of such agricultural biomass into densified products with a higher energy value and their subsequent combustion is associated with several questions. One of them is that rice straw exhibits a large formation of ash during combustion; thus, it is essential to know the nature of its ash melting behavior. Generally, during the combustion of straw biomass, ash sintering occurs in relatively low temperatures, resulting in the damaging of heating equipment. This negative aspect can be overcome by the addition of calcium-based additives. This paper aimed to study the ash melting behavior at a laboratory scale and to determine the ash melting points of rice straw mixed with calcium carbonate (CaCO3) and calcium hydroxide (Ca(OH)2) in different proportional ratios. The standardly produced ash samples from the rice straw obtained from Cambodia were constantly heated up in a muffle furnace, and characteristic temperatures of ash melting, i.e., shrinkage, deformation, hemisphere, and flow temperature, were recorded. The results showed that increasing the additive ratio did not bring linear growth of the melting temperatures. The addition of 1% CaCO3 showed an optimal positive impact of higher ash melting temperatures, and thus a better ability to abate the sintering of the rice straw ash.

Fusarium head blight (FHB) is a barley disease, which occurs every year in various areas of barley cultivation all over the world and the increasing incidence has been confirmed in the Czech Republic also during the last years. We aimed to emply AFLP (Amplified fragment length polymorphism) and SSR (Single sequence repeats) markers to describe diversity among breeding lines with a sufficient level of resistance towards FHB and to find marker(s) associated with the analysed traits. The number of eight accessions including five expected resistance donors and three sensitive lines were tested in the field and laboratory. The field values and the amount of deoxynivalenol were positively correlated (r = 0.92). The laboratory test and content DON manifested also a high correlation (r = 0.73). Several DH lines developed from androgenetic barley progenies of the F1 hybrids between the susceptible line PI 383933 and resistant line PEC 210 or the susceptible line PI 383933 and resistant cultivar Chevron were found resistant towards Fusarium infection in both the field and laboratory tests. Low infestation was found at line DH 37 from combination Chevron × PI 383933 and lines DH48, DH49, DH50 and DH55 from the combination PEC 210 × PI 383933. Cluster analyses based on 68 AFLP and 18 SSR markers demonstrate a genetic relationship among parental genotypes and DH lines. Some DH lines combined a sufficient degree of resistance against FHB and extract content (basic parameters malting quality). Statistically significant differences in malt-extract values were observed between groups of the DH lines possessing and not possessing the AFLP marker CAA/AGC 341bp. The markers will be further evaluated and optionally used for MAS.

Abstract:The success in hybridization of two-rowed spring barley genotypes of various origins was verified using the codominant SSR (Simple Sequence Repeat) marker HVWAXY which is located in the coding sequence of the waxy gene. The primer pair F 5' AAG ACG TGG TGT TCG TGT G 3' and R 5' ATG GTT CCA GGG GTA AGT TC 3' generated the PCR product of approximately 200 bp in the varieties/breeding lines Maridol, Bojos, Malz, Xanadu, Isotta, Josefin, Native, Sebastian, Conrad, KM 2436, KM 2439, KM 2629, KM-H-1320, whereas the product of about 250 bp was amplified in the lines KM 2416 and Br 7571h33. The parental genotypes possessing different alleles of the marker were crossed and the segregating lines of the F 3 generation were characterized employing molecular methods (marker-assisted selection). This prescreening enabled to work with a lower number of individuals (selfed individuals were excluded) at the initial stages of the breeding process leading to the acceleration of selection as a particular phase of breeding.