Authors:C.C. Dweba, H. Shimelis, T. Tapera, and T.J. Tsilo
Fusarium head blight (FHB) is an important disease of wheat causing significant yield and quality losses globally. Breeding for host plant resistance is an economic approach to FHB control and management. The aim of this study was to identify potential sources of resistance from newly developed recombinant inbred lines (RILs) of wheat. A total of 778 RILs were developed through a bi-parental mating design followed by continuous selfing and selection. The RILs along with their eight parental lines (Baviaans, Buffels, Duzi, #910, #936, #937, #942 and #1036) and FHB resistant check cultivar ‘Sumai 3’ and susceptible check ‘SST 806’ were field evaluated across four environments in South Africa. Fusarium graminearum isolates were artificially inoculated to initiate infection and disease development. The percentage of wheat spikes showing FHB symptoms were scored. The research identified six percent of the RILs with disease resistance. Heritability for FHB resistance was the highest (64%) indicating the possibility of achieving higher selection gains for FHB resistance across the selected environments. The following five RILs were identified as potential sources of resistance: 681 (Buffels/1036-71), 134 (Duzi/910-8), 22 (Baviaans/910-22), 717 (Baviaans/937-8) and 133 (Duzi/910-7) with mean FHB scores of 6.8%, 7.8%, 9.5%, 9.8% and 10%, respectively. The selected lines expressed comparatively similar levels of resistance compared with that of Sumai 3. The identified RILs are useful genetic resources for resistance breeding against FHB disease of wheat. Since the presence of the F. graminearum is associated with deoxynivalenol (DON) accumulation, the DON levels amongst the selected lines should be determined to ensure the release of improved wheat cultivars with reduced levels of DON accumulation.
Mycotoxins are natural compounds that may cause various adverse toxicological manifestations in humans and animals. The nature, the severity and scope of their adverse activity are varied and in general, even in small amount they have potent carcinogenic, genotoxic effect and injure the immune system. In order to provide high level of health protection for consumers, the European Union has established strict regulatory limits, whose implementation is enforced.The EC (2001) Commission Regulation sets maximum levels for some mycotoxins in foodstuffs: for aflatoxins, ochratoxin A, patulin, deoxynivalenol, zearalenone, fumonisins, T-2 and HT-2 toxins. Particular product categories are regulated under specific decisions ordaining control of imported consignments at the point of entry. Due to the fact that only aflatoxins are addressed in the specific decisions, they are the mostly detected and notified mycotoxins in the EU Rapid Alert System for Food and Feed (RASFF). The second most frequent group, Ochratoxin A is typically detected during internal EU market controls. Most RASFF notifications concern product categories falling under specific EU decisions, especially the Aflatoxin content of nuts and nut products. Significant amount of aflatoxins can be found also in dried fruits, spices and herbs.The article reviews and analyses the data available in rapid alert system concerning mycotoxins notification, and evaluates the usefulness of this information for risk assessment. The value of RASFF system is unquestionable and it fulfils its intended function included in its name. The system is a significant source of valuable information, but for risk assessment purposes, other additional information is needed. It could be used most effectively for risk assessment, if it was to provide data on the ratio of all/tested/positive lots and if the authorities provided not only the positive results, but also the exact mycotoxins level of every analysed sample.
Authors:Szabolcs Lechoczki-Krsjak, Beáta Tóth, Csaba Kótai, Imre Martonosi, László Farády, László Kondrák, Ágnes Szabó-Hevér, and Ákos Mesterházy
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