Authors:A. Mesterházy, B. Tóth, T. Bartók, and M. Varga
Type I resistance is a significant and powerful resistance component. Spraying inoculation covers reactions to both Type I and Type II. A significant synergetic effect was detected between Type I and Type II QTLs. It seems that Type I resistance at present cannot be directly measured, only as a difference between point and spraying inoculation. However, this does not influence the success of the selection. For breeding the spraying methodology is more suitable as it considers much wider genetic background than the point inoculation does. The highest resistance in the Szeged program was achieved by the use of exotic spring wheat sources in winter wheat, but excellent agronomy types were identified at a relative low ratio. Good or excellent resistance can be identified at a low rate in breeding material without exotic FHB resistance sources, but their agronomy value is much better. Ratio of high resistance is frequent in winter wheat lines created form winter and spring wheat resistance sources. An efficient phenotypic selection is inevitable. Repeatability of the test is generally good or excellent; LSD values are normally less than 10 % of the variation width. FDK and toxin measurements are integrant part of the program since 35 and 20 years, respectively. Several methodical considerations are discussed.
Authors:J. Varga, S. Kocsubé, Gy. Szigeti, V. Man, B. Tóth, Cs. Vágvölgyi, and T. Bartók
Black mould rot caused by black Aspergilli is an important post-harvest disease of onion worldwide. Usually Aspergillus niger is cited as the causative agent based on morphological criteria. In this study, the mycobiota and fumonisin contamination of mouldy onion bulbs purchased in Hungary were examined. All except one of the examined mouldy samples were found to be contaminated with black Aspergilli, which could be isolated both from the outer dry and the inner fleshy scales of onion bulbs. Species assignment of the isolates was carried out using sequence analysis of part of the calmodulin gene. Sequence data revealed that all 35 black Aspergilli isolated from onions belong to the Aspergillus awamori species. The range of fumonisin isomers present in the onion samples was also examined using reversed-phase high-performance liquid chromatography/electrospray ionization-ion trap mass spectrometry. Two of the examined onion samples were found to be contaminated with fumonisins at a rate of about 0.3 mg kg−1. This is the first report on fumonisin contamination of onion bulbs. The fumonisin isomers observed include fumonisins B2–4, 3-epi-FB4, iso-FB1 (FB6) and an iso-FB2,3 form. The range of fumonisin isomers detected in the onion bulbs indicates that probably A. awamori is responsible both for mould rot and fumonisin contamination of onions in Hungary.
Authors:A. Majzik, V. Hornok, D. Sebők, T. Bartók, L. Szente, K. Tuza, and I. Dékány
Due to the warm and favourably humid climate of Southern Hungary, the maize is one of the most important crops. The protection against crop damage caused by fusarium and Aspergillus species is essential. Detection of aflatoxin B1 (AFB1) molecules in cereal crops by selective sensors is important, while they can cause serious diseases in humans and animals if they enter the food chain. Our main objective was to develop selective AFB1 sensor with increased sensitivity applying βCD-functionalized gold nanoparticles (AuβCD NPs) in surface plasmon resonance (SPR) measuring apparatus. The nanoparticles ca. 10 nm in diameter were prepared in the presence of thiol-modified cyclodextrin. The adsorption isotherms of AFB1 on bare, thiol-modified cyclodextrin and AuβCD NPs covered Au film surface were calculated using SPR platform. The AFB1 concentration can be quantitatively determined in the 0.001–23.68 ng/mL range. The AuβCD NPs were found to be highly sensitive and exhibited a remarkably low limit of detection (LOD; 1 pg/mL) without using other analytical reagents.
Authors:Zs. Varanka, K. Aranka Deér, I. Rojik, I. Varanka, Kinga László, T. Bartók, J. Nemcsók, and Magdolna Ábrahám
Humics and pesticides are present in aquatic environment and the toxicological consequences of their chemical interaction is well studied. However, data concerning the mechanism of the biochemical action of humic-pesticide combinations are scarce, especially in vertebrates. Thus we have chosen to study the in vivo effects of the plant polyphenolic tannic acid and the pyrethroid insecticide deltamethrin [Decis] alone or in combination on hepatic xenobiotic-metabolizing enzyme activities and the associated redox-parameters in carp, as the complex assessment of these systems are regarded to serve as a relevant biomarker of environmental pollution. Stress effects and tissue damage were followed by determination of the plasma glucose level, the activities of plasma transaminases, and by electron microscopy. Tannic acid alone exerted weak prooxidant effect due to its marked antioxidant enzyme inhibitory activity. Deltamethrin, applied in a very low dose, induced oxyradical production in fish via activation of cytochrome P450 isozymes. This effect was promoted by the antioxidant enzyme inhibitory action of tannic acid, when the two chemicals were combined; however, the ultrastructural damage of the hepatocytes was reduced by the common cytoprotective capacity of the phenolic. Numerous humics are known to alter the toxicity of pesticides and their influence depends on their type and concentration. Therefore, our work taken together with other comparative studies may contribute to the assessment of the impact of humics in nature, especially in case of environmental pollution.