Gargouri Samia, Masiello Mario, Somma Stefania, Haidukowski Miriam, Khaterchi Rihab, Chekali Samira, Derouich Sonia, Balmas Virgilio, Moretti Antonio
Institut National de la Recherche Agronomique de Tunisie, rue HédiKarray, 2049, Tunisia.
Research National Council, Institute of Sciences of Food Production, CNR-ISPA, Via Amendola 122/O, 70126, Bari, Italy.
Fungal Biol. 2024 Dec;128(8 Pt B):2460-2470. doi: 10.1016/j.funbio.2024.07.002. Epub 2024 Jul 10.
Maize is a worldwide crop yet can be associated with mycotoxigenic fungi, much investigated in humid tropical and cooler, wet temperate regions. However, in hot, arid/semi-arid regions data on their occurrence are poor. In this paper, we focused on interactions between maize and Fusarium fungal species in Tunisia, which has a Mediterranean climate, with hot, dry summers and milder, damper winters. Maize kernels, stalks, and roots were sampled from 19 agricultural fields and 56, 72, and 88 % of samples, respectively, yielded Fusarium isolates. Based on molecular identifications, these were mainly F. verticillioides (67 %), and other species of Fusarium fujikuroi species complex and members of Fusarium incarnatum-equiseti-, oxysporum-, burgessii-, solani- and concolor species complexes. In addition, five isolates were identified as Clonostachys rosea. Fusarium verticilloides and Fusarium proliferatum, that produce fumonisins, suspected carcinogenic compounds, were isolated from all kinds of samples, whereas the other species were isolated only from root and stems. Fumonisin B was higher in kernels than in silage, while deoxynivalenol, potent protein synthesis inhibiting compound, was detected (at low levels) in grains and silage. A subset of selected strains, representative of all species identified, was also used to evaluate their ability to produce mycotoxins.Fusarium verticillioides, Fusariumproliferatum and Fusarium nygamai produced high levels of fumonisin Bin vitro, as well as beauvericin and enniatins. These findings confirm that, even in hot arid regions, which generally do not favour fungal growth, mycotoxin-producing fungi can be reason of concern for human and animal health.
玉米是一种全球性作物，但可能与产毒真菌有关，在潮湿的热带地区以及较凉爽、湿润的温带地区对此已有大量研究。然而，在炎热、干旱/半干旱地区，关于这些真菌的发生数据却很匮乏。在本文中，我们重点研究了突尼斯玉米与镰刀菌属真菌之间的相互作用。突尼斯属于地中海气候，夏季炎热干燥，冬季较为温和湿润。从19个农田采集了玉米籽粒、茎杆和根系样本，分别有56%、72%和88%的样本分离出了镰刀菌。基于分子鉴定，这些镰刀菌主要为轮枝镰孢菌（67%），以及藤仓镰孢菌复合种的其他物种，还有肉色镰孢菌-多主瘤梗孢菌复合种、尖孢镰孢菌、伯吉斯镰孢菌、茄病镰孢菌和同色镰孢菌复合种的成员。此外，有5个分离株被鉴定为粉红粘帚霉。从各类样本中均分离出了能产生伏马毒素（疑似致癌化合物）的轮枝镰孢菌和层出镰孢菌，而其他物种仅从根和茎中分离得到。籽粒中的伏马毒素B含量高于青贮饲料，而在谷物和青贮饲料中检测到了（低水平的）脱氧雪腐镰刀菌烯醇（一种强效的蛋白质合成抑制化合物）。还选取了代表所有已鉴定物种的一部分菌株来评估它们产生霉菌毒素的能力。轮枝镰孢菌、层出镰孢菌和尼日利亚镰孢菌在体外能产生高水平的伏马毒素，以及白僵菌素和恩镰孢菌素。这些研究结果证实，即使在通常不利于真菌生长的炎热干旱地区，产霉菌毒素的真菌也可能对人类和动物健康构成威胁。
