ABSTRACT Here, we report on the morphological, molecular, and chemical characterization of a novel Fusarium species recovered from the roots and rhizosphere of Macrochloa tenacissima (halfa, esparto, or needle grass) in central Tunisia. Formally described here as F. spartum, this species is a member of the Fusarium redolens species complex but differs from the other two species within the complex, F. redolens and F. hostae, by its endophytic association with M. tenacissima and its genealogical exclusivity based on multilocus phylogenetic analyses. To assess their sexual reproductive mode, a polymerase chain reaction (PCR) assay was designed and used to screen the three strains of F. spartum, 51 of F. redolens, and 14 of F. hostae for mating type (MAT) idiomorph. Genetic architecture of the MAT locus in the former two species suggests that if they reproduce sexually, it is via obligate outcrossing. By comparison, results of the PCR assay indicated that 13/14 of the F. hostae strains possessed MAT1-1 and MAT1-2 idiomorphs and thus might be self-fertile or homothallic. However, when the F. hostae strains were selfed, 11 failed to produce perithecia and one only produced several small abortive perithecia. Cirrhi with ascospores, however, were only produced by 8/28 and 4/84 of the variable size perithecia, respectively, of F. hostae NRRL 29888 and 29890. The potential for the three F. redolens clade species to produce mycotoxins, pigments, and phytohormones was assessed by screening whole genome sequence data and by analyzing extracts on cracked maize kernel cultures via liquid chromatography–mass spectrometry.

中文翻译：

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来自突尼斯的 Macrochloa tenacissima（esparto 或针草）的内生菌是 Fusarium redolens 物种复合体中的一个新物种

摘要 在这里，我们报告了从突尼斯中部 Macochloa tenacissima（半草、esparto 或针草）的根和根际回收的新型镰刀菌的形态、分子和化学特征。这里正式描述为 F. spartum，该物种是 Fusarium redolens 物种复合体的成员，但与复合体中的其他两个物种 F. redolens 和 F. hostae 不同，因为它与 M. tenacissima 的内生关联及其谱系排他性基于多位点系统发育分析。为了评估它们的有性生殖模式，设计并使用聚合酶链反应 (PCR) 测定法筛选 3 株 F. spartum、51 株 F. redolens 和 14 株 F. hostae 的交配型 (MAT) 特异型。前两个物种中 MAT 基因座的遗传结构表明，如果它们进行有性繁殖，则是通过专性异交进行的。相比之下，PCR 分析的结果表明，13/14 的宿主菌菌株具有 MAT1-1 和 MAT1-2 独特型，因此可能是自育的或同种的。然而，当 F. hostae 菌株进行自交时，11 个未能产生周囊壳，一个仅产生了几个小的流产的周囊壳。然而，具有子囊孢子的 Cirrhi 仅分别由 F. hostae NRRL 29888 和 29890 的 8/28 和 4/84 的可变大小的perithecia 产生。三种 F. redolens 进化枝物种产生霉菌毒素、色素、