Four mycangium types and four genera of ambrosia fungi suggest a complex history of fungus farming in the ambrosia beetle tribe Xyloterini
Four mycangium types and four genera of ambrosia fungi suggest a complex history of fungus farming in the ambrosia beetle tribe Xyloterini
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DOI：
10.1080/00275514.2020.1755209
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发表时间：
2020-06-18
期刊：
影响因子：
2.8
通讯作者：
Bateman, Craig C.
中科院分区：
文献类型：
--
作者：
Mayers, Chase G.;Harrington, Thomas C.;Bateman, Craig C.
豚草甲虫培育真菌品种（豚草真菌），并在称为菌管的储存器官中携带真菌共生体的繁殖体，这种器官出现在身体的各个部位，大小和复杂性差异很大。豚草真菌的进化与携带它们的菌体的进化和发育密切相关。正在研究的豚草甲虫部落 Xyloterini 包括具有未表征的豚草真菌和菌丝的谱系，这提供了一个机会来测试单个豚草甲虫谱系中不同菌丝类型的发育是否与其真菌共生体的伴随多样性相对应。我们收集了所有三个 Xyloterini 属（Trypodendron、Indocryphalus 和 Xyloterinus politus）的代表，并通过纯培养和 DNA 测序对它们的豚草真菌进行了表征。 7个Trypodendron属物种的前胸mycangia均产生Phialophoropsis(Microascales) ambrosia真菌，其中包括3个新种，但这些亲缘关系并不都是物种特有的。Indocryphalusmycangia在亚洲I中首次得到表征。耻骨。它们的三角形前胸腔远小于锥体，并且意外地携带一种未描述的 Toshionella (Microascales) 物种，它们是亚洲小蠹 (Scolytoplatypodini) 的豚草真菌。Xyloterinus politushas 两种不同的菌管，每种都有不同的豚草真菌：Raffaeleacf.canadensisRNC5 (Ophiostomatales)雌性浅前胸蕈癌中存在 Kaarikia abrahamsonii（Sordariomycetes，未确定的属，与 Distoseptisporaceae 具有亲和力），这是一种与其他已知豚草真菌无关的新属和新种。除了它们高度适应的真菌共生体之外，还有Trypodendron和X。 politus 在他们的画廊中拥有令人惊讶的多样性的兼性共生体，包括拉斐尔 (Raffaelea)。豚草真菌和菌丝菌的多样性表明，Xyloterini 部落的历史上有多个祖先品种的捕获或转换，每个品种都与菌丝菌解剖学的独特适应有关。这进一步支持了这样的理论：新的真菌类型的发展是豚草甲虫及其共适应真菌互利共生进化中的关键事件。
Ambrosia beetles farm fungal cultivars (ambrosia fungi) and carry propagules of the fungal mutualists in storage organs called mycangia, which occur in various body parts and vary greatly in size and complexity. The evolution of ambrosia fungi is closely tied to the evolution and development of the mycangia that carry them. The understudied ambrosia beetle tribe Xyloterini included lineages with uncharacterized ambrosia fungi and mycangia, which presented an opportunity to test whether developments of different mycangium types in a single ambrosia beetle lineage correspond with concomitant diversity in their fungal mutualists. We collected representatives of all three Xyloterini genera (Trypodendron, Indocryphalus, andXyloterinus politus) and characterized their ambrosia fungi in pure culture and by DNA sequencing. The prothoracic mycangia of sevenTrypodendronspecies all yieldedPhialophoropsis(Microascales) ambrosia fungi, including three new species, although these relationships were not all species specific.Indocryphalusmycangia are characterized for the first time in the AsianI. pubipennis. They comprise triangular prothoracic cavities substantially smaller than those ofTrypodendronand unexpectedly carry an undescribed species ofToshionella(Microascales), which are otherwise ambrosia fungi of AsianScolytoplatypus(Scolytoplatypodini).Xyloterinus politushas two different mycangia, each with a different ambrosia fungus:Raffaeleacf.canadensisRNC5 (Ophiostomatales) in oral mycangia of both sexes andKaarikia abrahamsonii(Sordariomycetes, genus incertae sedis with affinity for Distoseptisporaceae), a new genus and species unrelated to other known ambrosia fungi, in shallow prothoracic mycangia of females. In addition to their highly adapted mycangial mutualists,TrypodendronandX. politusharbor a surprising diversity of facultative symbionts in their galleries, includingRaffaelea. A diversity of ambrosia fungi and mycangia suggest multiple ancestral cultivar captures or switches in the history of tribe Xyloterini, each associated with unique adaptations in mycangium anatomy. This further supports the theory that developments of novel mycangium types are critical events in the evolution of ambrosia beetles and their coadapted fungal mutualists.