Tuber aestivum, one of the most sought out and marketed truffle species in the world, is morphologically similar to Tuber mesentericum, which is only locally appreciated in south Italy and north-east France. Because T. aestivum and T. mesentericum have very similar ascocarp features, and collection may occur in similar environments and periods, these two species are frequently mistaken for one another. In this study, 43 T. aestivum and T. mesentericum ascocarps were collected in Italy for morphological and molecular characterization. The morphological and aromatic characteristics of the fresh ascocarps were compared with their spore morphology. Afterwards, we amplified and sequenced the elongation factor 1-α (EF1α) locus and built maximum likelihood trees to assess phylogenetic similarities between the two species. Tuber aestivum and T. mesentericum sequences cluster into different clades, with T. mesentericum sequences divided into three different sub-clades. According to their morphological features, three samples (T7, T8 and T12) were classified as T. mesentericum. However, when fresh, these ascocarps lacked the typical phenolic aromatic note. These specimens fall into the sub-clade III of the T. mesentericum phylogeny, which has the lowest genetic distance from the T. aestivum clade.

中文翻译：

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块根肠和块茎松露：基于形态学和系统发育分析的新见解

小麦块茎是世界上最受欢迎的松露品种之一，在形态上与块茎马铃薯类似，后者仅在意大利南部和法国东北部受到赞赏。由于普通小麦和中肠小麦的果皮具有非常相似的特征，并且收集可能在相似的环境和时期进行，因此这两个物种经常被误认为彼此。在这项研究中，有43粒小麦和棉球菌在意大利收集了椰果，以进行形态和分子表征。将新鲜椰果的形态和芳香特性与其孢子形态进行了比较。之后，我们对延伸因子1-α（EF1α）基因座进行了扩增和测序，并建立了最大似然树来评估两个物种之间的系统相似性。小麦块茎和肠球菌序列分为不同的进化枝，而肠球菌序列分为三个不同的子进化枝。根据它们的形态特征，将三个样品（T7，T8和T12）分类为肠球菌。然而，当新鲜时，这些椰果缺乏典型的酚类芳香气味。这些标本落入肠系膜球囊系统发育的III亚分支，该亚系与小麦球囊进化枝的遗传距离最低。