In order to find out the contamination of mycotoxins in Triticeae crops of Qinghai-Tibet Plateau, a total of 153 Triticeae crop fruits were collected as target samples, and 22 mycotoxins were tested. High detection rate was found in the Alternaria mycotoxins, including tentoxin (TEN), tenuazonic acid (TEA) and alternariol (AOH) toxins. To further clarify the production rules of Alternaria mycotoxins. A number of 9 high yield toxic strains were selected from 65 bacterial strains and the gene sequences of each were determined. The nine selected Alternaria alternate were cultured under specific pH of the culture medium, temperature and ultraviolet (UV) irradiation, and their growth and toxicity were analyzed. The results showed that the toxic capacity of most A. alternate increased with the increase of culture environment temperature and decreased with the increase of UV irradiation. However, the production of some toxins did not meet this principle, or even met the principle of relativity. In the culture experiments, a total of five Alternaria toxins were detected as positive, which were TEN, AOH, alternariol monomethyl ether (AME), TEA, and Alternaria (ALT). The altenusin (ALS) toxin was not detected in the metabolites of the nine Alternaria strains. It indicated that the TEN, AOH, AME, TEA, and ALT toxins should be particularly valued in the future risk assessments. This finding provided comprehensive information of mycotoxins contamination in the Tibetan Plateau Triticeae crops, it pointed out a direction to the Tibetan Plateau food crops’ quality control.

The present study was performed to evaluate the effect of crop rotation on Fusarium mycotoxins and species in cereals in Sichuan Province. A total of 311 cereal samples were randomly collected and analyzed from 2018 to 2019 in Sichuan Province. The results of mycotoxin analysis showed that the major trichothecene mycotoxins in Sichuan Province were nivalenol (NIV) and deoxynivalenol (DON), and the mean concentration of total trichothecenes (including NIV, fusarenone X [4ANIV], DON, 3-acetyldeoxynivalenol [3ADON], and 15-acetyldeoxynivalenol [15ADON]) in wheat was significantly higher than that in maize and rice. The concentration of total trichothecenes in the succeeding crops was significantly higher than that in the previous crops. In addition, wheat grown after maize had reduced incidence and concentration of trichothecene mycotoxins compared with that grown after rice, and ratooning rice grown after rice had increased incidence and concentration of trichothecene mycotoxins. Our data indicated that Fusarium asiaticum with the NIV chemotype was predominant in wheat and rice samples, while the number of the NIV chemotypes of F. asiaticum and Fusarium meridionale and the 15ADON chemotype of Fusarium graminearum in maize were almost the same. Although the composition of Fusarium species was affected by crop rotations, there were no differences when comparing the same crop rotation except for the maize-wheat rotation. Moreover, the same species and chemotype of Fusarium strains originated from different crops in various rotations, but there were no significant differences in pathogenicity in wheat and rice. These results contribute to the knowledge of the effect of crop rotation on Fusarium mycotoxins and species affecting cereals in Sichuan Province, which may lead to improved strategies for control of Fusarium mycotoxins and fungal disease in China.