The complex of mycotoxins in oilseed rape and turnip rape during spring and summer seasons

Oilseed rape and turnip rape crops are widely used to produce seeds and green mass (T.A. Egorova et al., 2015; A.V. Valitov et al., 2018; V.T. Volovik, 2020). The plants are also considered promising siderates that saturate the soil with potassium, phosphorus and nitrogen, and their introduction into crop rotation has a positive effect on grain yields. Recently, the composition and content of mycotoxins were studied in vegetating white mustard and meadow grasses of the Cruciferous family with an assessment of seasonal variability and organotropy (A.A. Burkin et al., 2019; A.A. Burkin, G.P. Kononenko, 2022). In this study, it was established for the first time that cyclopiazonic acid. ergot alkaloids, alternariol and emodin are included in the group of the main contaminants of oilseed rape and turnip rape before flowering, as well as data on the expansion of the composition of the mycotoxin complex during budding and the heterogeneous distribution of these substances by plant organs has been received. The aim of this work was mycotoxicological examination of winter turnip rape Brassica campestris fr. biennis and winter and spring oilseed rape Brassica napus L. ssp. oleifera (Metzg.) Sinsk in the spring-summer growth period - from the rosette phase to the completion of budding, as well as in vegetative and generative organs of plants during flowering and formation of siliques. Vegetating plants were collected from the experimental plots of the Williams Federal Research Center VIC. Winter oilseed rape and turnip rape (sown on September 8, 2020) were collected starting from April 23, 2021, spring rapeseed (sown on May 21, 2021) - from June 25, 2021 weekly. The aboveground parts of whole plants were cut at a height of 3-5 cm from the soil surface, in the phases of flowering and silique formation, the plants were divided into leaves, stems, flowers and siliques. After drying and grinding in a laboratory mill, 349 samples were analyzed. The content of T-2 toxin (T-2), deoxynivalenol (DON), zearalenone (ZEN), fumonisins of group B (FUM), ergot alkaloids (EA), alternariol (AOL), roridin A (ROA), aflatoxin B1 (AB1), sterigmatocystin (STE), cyclopiazonic acid (CPA), emodin (EMO), ochratoxin A (OA), citrinin (CIT), mycophenolic acid (MPA), PR-toxin (PR) were determined according to a unified methodology (GOST 31653-2012. Feed. Method of enzyme immunoassay of mycotoxins. M., 2012) using a panel of 15 certified commercial and research enzyme immunoassay systems. The ground samples were extracted with a mixture of acetonitrile and water, 84:16 v/v, at 10 ml per 1 g sample. Indirect competitive enzyme-linked immunosorbent assay (ELISA) was performed after tenfold dilution of extracts with phosphate-salt buffer solution (pH 7.4) with Tween 20. In the entire sample of samples, 14 analytes out of 15 were detected (no POA was found). In winter crops in the rosette-stemming phases, EA, AOL, CPA and EMO were detected in part of the samples with the values located near the limits of the method definition, in the budding phase, an increase in the accumulation of EA, AOL, CPA was observed with cases of detection of EMO, AB1, STE, OA, MPA and the appearance of fusariotoxins ZEN, FUM. Spring oilseed rape was less contaminated than winter form. During flowering and maturation of siliques, plants showed common patterns of the distribution of mycotoxins by organs, i,e., a greater accumulation in leaves compared to stems and a decrease in the content in ripening siliques. In the flowers of all crops, frequent contamination of MPA was detected, and, as a rule, in combination with EMO, and mycotoxins were found in winter crops that were absent during the initial growth period (CIT, PR, T-2, and DON). The possibility is discussed of participation of potentially toxigenic micromycetes of the genera Fusarium , Alternaria , Penicillium , Aspergillus , Mucor in plant contamination.