The occurrence of black aspergilli in onions has been reported as frequent, and this group of fungi harbors potentially toxigenic species. In addition, Aspergillus niger has been reported as the causative agent of black mold rot, an important postharvest disease that causes damage throughout the world. Brazil stands out as one of the world's largest onion producers. However, few studies have been conducted to investigate the mycobiota in Brazilian onions. For this reason, we investigated the mycobiota of 48 market (n = 25) and field (n = 23) onion bulb samples. Nineteen soil samples were collected from the same fields and evaluated. In field onions and soil samples, Penicillium spp. was the prevalent fungal group, whereas in market samples A. section Nigri was the most frequent group. Due to the taxonomic complexity of this group, species identification was supported by phylogenetic data (CaM gene). A. welwitschiae was the most prevalent species in market samples. Black aspergillus strains were evaluated for fumonisin B₂ (FB₂) and ochratoxin A (OTA) production. Overall, 53% and 2.2% of the strains produced FB₂ and OTA, respectively. The occurrence of FB₂ and OTA was also investigated in onion bulb samples but none showed contamination with these mycotoxins.

据报道，洋葱中黑曲霉的发生频率很高，而这一类真菌具有潜在的产毒物种。另外，据报道黑曲霉是黑霉病的病原体，黑霉病是一种重要的收获后疾病，在全世界范围内引起破坏。巴西是世界上最大的洋葱生产国之一。然而，很少有研究来调查巴西洋葱中的真菌群。因此，我们调查了48个市场 洋葱样品（n  = 25）和大田洋葱样品（n = 23）的分枝杆菌。从相同的田地收集了19个土壤样品并进行了评估。在田间洋葱和土壤样品中，青霉菌spp。是普遍的真菌群，而市场样品中一个。Nigri节是最常出现的小组。由于该组的分类复杂性，物种鉴定得到了系统发育数据（CaM基因）的支持。草是市场样品中最流行的物种。评价了黑曲霉菌株的伏马毒素B ₂（FB ₂）和曲霉毒素A（OTA）的产生。总体而言，53％和2.2％的菌株分别产生FB ₂和OTA。还对洋葱鳞茎样品中的FB ₂和OTA的存在进行了研究，但没有一个表明这些霉菌毒素污染了。