Authors:Tihana Marček, Marija Viljevac Vuletić, and Valentina Španić
In wheat, Fusarium fungus promotes the appearance of destructive disease named as Fusarium head blight (FHB) that can cause grain yield reduction and mycotoxin accumulation. The focus of this research was to verify the influence of Fusarium graminearum and F. culmorum on wheat genotypes with different susceptibility to FHB: “Super Žitarka” (susceptible), “Lucija” (moderately resistant) and “Apache” (resistant). The experiment was performed under field conditions by artificial spore inoculation of ears at the flowering stage. The effectiveness of antioxidative enzymes, hydrogen peroxide (H2O2) content and malondialdehyde (MDA) content were observed at several sampling points after Fusarium inoculation (3, 15 and 24 hours). “Lucija” responded to pathogen by increase of guaiacol peroxidase (POD) activity, high H2O2 and MDA content in the early post-inoculation times (3 and 15 hours), compared to control. “Super Žitarka” displayed inhibition of catalase (CAT) activity throughout the whole time course of the experiment. Infected plants of “Apache” showed notable decline in MDA content over time. Moreover, in “Apache” increased H2O2 accumulation was observed immediately after Fusarium exposure (3 and 15 hours), compared to 24 hours. Rapid overproduction of H2O2 under Fusarium stress marked “Apache” as FHB-resistant.
Authors:S. Popovski, K. Kos, B. Jakovac Strajn, and F.A. Celar
The genus Fusarium consists of multiple diverse species, which, as a result of their frequency in nature and pathogenicity, are significant in agriculture, as well as in human and veterinary medicine. In the course of field trials, by using standard phytopathological methods, and performing analyses of 19 different varieties of wheat and a portion of infected grains gathered from two distinct locations in Slovenia, we have determined the presence of various phytopathogenic species of the genus Fusarium. Because of the reliability, the experiment was performed in two consecutive years, 2012 and 2013. A laboratory analysis was conducted with an ELISA test on all grain samples for the determination of deoxynivalenol (DON) concentration. The results show that the main differences in the infection levels (F. culmorum + F. graminearum; FC + FG) of wheat samples were found in Jable (humid area), at the same time showing higher levels of DON content than Rakičan (dry area). Such a statement is supported by correlation test, where correlation is evident between FC + FG and DON in every variation. The data for both wheat types (awned and awnless) together showed that the grain in Jable is statistically significant more infected by FC + FG when compared to that in Rakičan. Moreover, our descriptive analysis confirms that the infection rate of grain with FC and FG shows a strong correlation with the emergence of DON.
Authors:Y. Gherbawy, M. El-Tayeb, T. Maghraby, Y. Shebany, and B. El-Deeb
Inoculating wheat (cv. Giza 164) with various Fusarium species had different effects on the catalase (CAT), peroxidase (POX) and ascorbate peroxidase (APX) activity in different plant tissues. The CAT activity induced in the shoots of wheat plants by some pathogens (F. merismoides, F. moniliforme, F. poae and F. sambucinum) was relatively higher than that induced by other pathogens. The results showed an increase in POX activity in infected shoots except those inoculated with F. sambucinum, where the POX activity decreased. Inoculating wheat plants with individual Fusarium species or with a mixture of pathogens caused an increase in APX in the shoots, except for those treated with F. poae, where the APX activity decreased. The activity of these antioxidant enzymes thus increased in most cases in the shoot system of wheat plants under Fusarium infection. Investigations on the metabolic activity of wheat plants inouculated with individual Fusarium species or with a mixture of pathogens showed higher contents of all the protein fractions, soluble sugars, total free amino acids and proline. The K+ and Ca2+ concentrations decreased to various extents in different cases. The Na+ content increased in wheat shoots, especially after inoculation with F. merismoides. The results signify that the most serious infection was caused by F. culmorum, F. graminearum and F. oxysporum and by a mixture of all the Fusarium species.
Authors:Zs. Koncz, D. Magyar, Z. Naár, A. Kiss, and Á. Szécsi
The species-specific PCR assays correctly identified pure cultures of
(13 isolates), and
(6 isolates) originated from Hungarian wheat grain.The PCR-based assays described in this study can be used for the routine detection and identification of above-mentioned Fusaria without morphological determination.
The aim of the study was to evaluate the effect of the artificial inoculation of barley kernels and leaves with a suspension of spores and mycelium of species belonging to the genera Ascochyta, Bipolaris, Drechslera and Fusarium. The following procedures were applied: inoculation of kernels germinating on blotting paper, inoculation of kernels germinating in the soil and spraying of young barley plants. Intensity of the occurring disease symptoms depended on the fungal species used and the method of inoculation. All genera of fungi used for inoculation of kernels on blotting paper statistically significantly reduced the percentage of germinated kernels. In the case of inoculation of kernels sown in the soil, emergence rates of barley plants were statistically significantly reduced only by B. sorokiniana (22.5–70%) and Fusarium sp. (5–55%), the control 92.5–95%. The use of B. sorokiniana in the inoculation of young barley plants caused spots (30–60% of infected plants), which were not observed in species from the other genera.