**2. Materials and methods**

trichothecene mycotoxins having a common chemical structure and a similar mode of action [1]. Among them, T-2 toxin (3α-hydroxy-4β,15-diacetoxy-8α-(3-methylbutoxy)-12,13 epoxytrichothec-9-ene), and its major metabolite HT-2 toxin (3α,4β-dihydroxy-15-acetoxy-8α-(3-methylbutoxy)-12,13-epoxy-trichothecene), represent not only type A trichothecene mycotoxins produced mainly by the *Fusarium langsethiae*, but also the *Fusarium poae* and the *Fusarium sporotrichioides* [2, 3]. These toxins are produced at temperatures ranging from −2 to 35°C and with water activities above 0.88 [4, 5], and are frequently responsible for the contamination of different grains such as maize, oat, barley, wheat, rice and soya beans. Weather conditions, varieties and the sowing time are the most important factors influencing the T-2

42 Fusarium - Plant Diseases, Pathogen Diversity, Genetic Diversity, Resistance and Molecular Markers

Type A trichothecenes, T-2 and HT-2 toxins included, are generally more toxic than type B trichothecenes (e.g. deoxynivalenol and nivalenol). Structure/activity-relationship studies revealed that 12,13-epoxide group and C9-C10-double bond are essential for their toxicity [7]. Toxicological studies show that T-2 toxin is a very potent cytotoxic and immunosuppressive agent, which can cause acute intoxication and chronic diseases in both humans and animals [6]. Given that T-2 toxin is metabolised into HT-2 toxin after ingestion, they are considered to be equally toxic [8]. The symptoms of acute T-2 intoxication of different mammalian species include skin necrosis, asthenia, lack of appetite, panting, vomiting, diarrhoea, anorexia, myocardial damage, lethargy, as well as haemorrhages and necrosis of the epithelium of the stomach and intestines, bone marrow, spleen, testis and ovary [1, 8–10]. The International Agency for Research on Cancer (IARC) classified T-2 toxin into Group 3 carcinogens because of the lack of data on its carcinogenicity in humans and only limited evidence on its carcino-

Data collected in a number of European countries have shown substantial variations in *Fusarium* mycotoxin levels across various cereal types, various countries and various investigated periods [12, 13]. Croatia, as a Central European country, falls into the group of countries in which contamination with *Fusarium* mycotoxins is a frequent occurrence [14, 15]. Since data on the occurrence of T-2 and HT-2 toxins in cereals and cereal by-products are still very limited, the European Commission recommended the member states to gather reliable data on year-to-year variations of these mycotoxins in order to be able to establish their maximal levels (MLs) in different food and feed in the near future [6, 16, 17]. In 2013, the European Commission gave recommendations (Commission Recommendation 2013/165/EU) regarding indicative levels of T-2 and HT-2 toxin in cereals and cereal-based products intended for food and feed. In this document, the Commission also recommended further investigations into the effects of food processing and agronomic factors on the presence of T-2 and HT-2 toxin and different factors favouring high level-contaminations with these toxins, so as to be able to identify measures to be taken to avoid or reduce the above [18]. In view of the evidenced toxicity of T-2 and HT-2 toxin, there exists the need for further collection of data on their presence in different cereals intended for food and feed production. In their recent study, Pleadin et al. [17] stated that further studies shall also be performed in Croatia in order to investigate into the conditions favouring T-2 and HT-2 production and to identify measures that are to

and HT-2 toxin production [6].

genicity in experimental animals [11].
