Fungal and mycotoxin contamination of maize hybrids in different maturity groups

Abstract

In the present study, the frequency of toxigenic fungi and occurrence of aflatoxin B1 (AFB1), deoxynivalenol (DON) and total fumonisins (FBs) in the kernels of six maize hybrids from different FAO maturity groups (ZP 341, ZP 427, ZP 434, ZP 560, ZP 606, ZP 666) in three localities (Belosavci, Lađevci and Divci) in Serbia, during the harvest in 2013, was investigated. Using standard mycological tests of maize kernels, the presence of potentially toxigenic fungi species from the genera Aspergillus, Fusarium and Penicillium was found. In the studied localities, species Fusarium verticillioides was the most frequently isolated from the most hybrids, with a maximum frequency of 30%, while the presence of Aspergillus spp. ranged from 0 to 16%, and Penicillium spp. from 0 to 20%. By applying Immunoadsorbent enzymatic assay (ELISA) the concentrations of AFB1, DON and FBs were determined in maize. The differences between tested hybrids in the level of mycotoxins in kernels were statistically significant (P≤0.01) for DON and FBs, but not for the content of AFB1. Also, the interaction between the hybrid and location was significant (P≤0.01) for the level of DON and FBs, while there was no statistical significance for the level of AFB1. Maximum values of AFB1, DON and FBs level were 1.02 μg kg-1 (ZP 427), 12 μg kg-1 (ZP 341) and 1528.56 μg kg-1 (ZP 427). The concentrations of the tested mycotoxins in kernels did not exceed the maximum allowed limits stipulated by Serbian regulations (Službeni glasnik RS, 2014). Given that agro-ecological conditions in Serbia are favourable for the occurrence of toxigenic fungi and their mycotoxins, it is necessary to exert the control of maize kernels annually, in harvest and postharvest periods.

U radu je ispitivana učestalost potencijalno toksigenih vrsta gljiva i prirodna pojava aflatoksina B1 (AFB1), deoksinivalenola (DON) i ukupnih fumonizina (FBs) u zrnu šest hibrida kukuruza iz različitih FAO grupa zrenja (ZP 341, ZP 427, ZP 434, ZP 560, ZP 606, ZP 666) u tri lokaliteta (Belosavci, Lađevci i Divci) u Srbiji, tokom berbe u 2013. godini. Primenom standardnih mikoloških ispitivanja zrna kukuruza ustanovljeno je prisustvo potencijalno toksigenih vrsta gljiva iz tri roda: Aspergillus, Fusarium i Penicillium. U ispitivanim lokalitetima, vrsta Fusarium verticillioides je bila najčešće izolovana kod većine hibrida, sa maksimalnom učestalošću od 30%, dok je prisustvo Aspergillus spp. bilo od 0 do 16%, a Penicillium spp. od 0 do 20%. Primenom imunoadsorpcione enzimske metode (ELISA) određen je sadržaj AFB1, DON i FBs u zrnu kukuruza. Razlike između ispitivanih hibrida u sadržaju mikotoksina u zrnu bile su statistički značajne (P≤0,01) za DON i FBs, ali ne i za sadržaj AFB1. Isto tako, interakcija između hibrida i lokaliteta je bila značajna (P≤0,01) za sadržaj DON i FBs, dok nije bilo statističke značajnosti za sadržaj AFB1. Maksimalne koncentracije AFB1, DON i FBs bile su 1,02 μg kg-1 (ZP 427), 12 μg kg-1 (ZP 341) i 1528,56 μg kg-1 (ZP 427). U zrnu kukuruza sadržaj ispitivanih mikotoksina nije premašio maksimalno dozvoljene vrednosti propisane Pravilnikom o maksimalno dozvoljenim količinama ostataka sredstava za zaštitu bilja u hrani i hrani za životinje i o hrani i hrani za životinje za koju se utvrđuju maksimalno dozvoljene količine ostataka sredstava za zaštitu bilja (Službeni glasnik RS, 2014). S obzirom da su agroekološki uslovi u Srbiji povoljni za pojavu toksigenih gljiva i njihovih mikotoksina, neophodno je svake godine vršiti kontrolu zrna kukuruza, kako u žetvenom, tako i u postžetvenom periodu.