Visual, instrumental, mycological and mycotoxicological characterization of wheat inoculated with and protected against Alternaria spp/Vizuelna, instrumentalna, mikoloska i mikotoksikoloska karakterizacija psenice gajene u uslovima stimulacije i inhibicije zarazenosti sa Alternaria spp

The aim of this work was to characterize visual properties, instrumentally measured colour properties, field fungi presence and Alternaria toxins levels in wheat samples grown under conditions aimed at inhibition and stimulation of wheat infection with fungi from the Alternaria genus. Experiment was carried out on the wheat treated by fungicide and wheat inoculated by Alternaria spp., while non treated wheat was used as a control. Statistically significant difference was observed between all three treatments using visual scale. Protected wheat samples were significantly different from other samples in terms of all measured colour parameters while inoculated and control wheat samples were significantly different in terms of lightness and dominant wavelength. Identification of field fungi in the all examined wheat samples showed that the dominant mycotoxigenic fungus was Alternaria spp., followed by Fusarium spp. The content of Alternaria toxins in samples of wheat hulls and dehulled kernels point out at higher concentrations of Alternaria toxins in hulls than in dehulled kernels. Keywords: colour, wheat ears, wheat kernels, field fungi, Alternaria toxins Zita predstavljaju primarni izvor energije u ljudskoj ishrani, pri cemu u svetskoj proizvodnji psenica zauzima trece mesto po proizvedenoj kolicini. Skorasnja istrazivanja su pokazala da su pored Fusarium spp. gljive iz roda Alternaria postale dominantni zagadivaci psenicnog zrna. Pored patogenosti i narusavanja kvaliteta psenicnog zrna, pojedine vrste roda Alternaria su poznate kao proizvodaci sekundarnih toksicnih metabolita, Alternaria toksina, koji mogu biti stetni po zdravlje ljudi i zivotinja. Cilj ovog rada je bio karakterizacija vizuelno i instrumentalno merenih svojstava boje, prisustva i zastupljenosti poljskih fitopatogenih gljiva i Alternaria toksina u uzorcima psenice gajenih u uslovima usmerenim na inhibiciju i stimulaciju razvoja gljiva iz roda Alternaria. Eksperiment je izveden na uzorcima psenice tretirane fungicidom i na uzorcima psenice inokulisane sa Alternaria spp., dok je netretirana psenica koriscena kao kontrola. Boja klasova psenice koji su predstavljali vizuelnu skalu je instrumentalno izmerena radi utvrdivanja korelacije izmedu ove dve metode. Grupisanje psenicnih klasova po vrednostima svetloce (L*) bilo je u skladu sa koriscenom skalom za vizuelnu ocenu boje. Stavise, vrednosti svetloce su bile u najvecoj negativnoj korelaciji (20 0,97, p < 0,001) sa vizuelnom skalom. Pri vizuel