Abstract:
Ectomycorrhizal fungi (ECM) sustain nutrient recycling in most terrestrial ecosystems, yet we know little about what major biogeographical events gave rise to present-day diversity and distribution patterns. Given the strict relationship between some ECM lineages and their hosts, geographically well-sampled phylogenies are central to understanding major evolutionary processes of fungal biodiversity patterns. Here, we focus on Amanita sect. Vaginatae to address global diversity and distribution patterns. Ancestral-state-reconstruction based on a 4-gene timetree with over 200 species supports an African origin between the late Paleocene and the early Eocene (ca. 56 Ma). Major biogeographic \"out-of-Africa\" events include multiple dispersal events to Southeast Asia (ca. 45-21 Ma), Madagascar (ca. 18 Ma), and the current Amazonian basin (ca. 45-36 Ma), the last two likely trans-oceanic. Later events originating in Southeast Asia involve Nearctic dispersal to North America (ca. 20-5 Ma), Oceania (Australia and New Zealand; ca. 15 Ma), and Europe (ca. 10-5 Ma). Subsequent dispersals were also inferred from Southeast Asia to East Asia (ca. 4 Ma); from North America to East Asia (ca. 11-8 Ma), Southeast Asia (ca. 19-2 Ma), Northern Andes (ca. 15 Ma), and Europe (ca. 15-2 Ma), respectively; and from the Amazon to the Caribbean region (ca. 25-20 Ma). Finally, we detected a significant increase in the net diversification rates in the branch leading to most northern temperate species in addition to higher state-dependent diversification rates in temperate lineages, consistent with previous findings. These results suggest that species of sect. Vaginatae likely have higher dispersal ability and higher adaptability to new environments, in particular compared to those of its sister clade, sect. Caesareae. Overall, the much wider distribution of A. sect. Vaginatae, from pan-tropical to pan-arctic, provides a unique window to understanding niche conservatism across a species-rich clade of ECM fungi.
摘要:
外生菌根真菌(ECM)在大多数陆地生态系统中维持养分循环,然而,我们对哪些主要的生物地理事件导致了当今的多样性和分布模式知之甚少。鉴于某些ECM谱系与其宿主之间的严格关系,地理上良好采样的系统发育对于理解真菌生物多样性模式的主要进化过程至关重要。这里,我们关注的是Amanita教派.阴道科以解决全球多样性和分布模式。基于具有200多种物种的4基因时间表的祖先状态重建支持了古新世晚期和始新世早期之间的非洲起源(约56Ma)。主要的生物地理“非洲以外”事件包括向东南亚的多次扩散事件(约45-21Ma),马达加斯加(约18Ma),和当前的亚马逊盆地(约45-36Ma),最后两次可能的跨洋航行.后来起源于东南亚的事件涉及向北美传播的近距离传播(约20-5Ma),大洋洲(澳大利亚和新西兰;约15Ma),和欧洲(ca。10-5Ma)。随后的传播也从东南亚到东亚(约4Ma);从北美到东亚(约11-8Ma),东南亚(约19-2Ma),北安第斯山脉(约。15Ma),和欧洲(ca。15-2Ma),分别;以及从亚马逊河到加勒比地区(约25-20Ma)。最后,我们发现,除了温带谱系中更高的状态依赖性多样化率之外,导致大多数北温带物种的分支净多样化率显着增加,与以前的发现一致。这些结果表明该物种。阴道可能具有更高的扩散能力和对新环境的更高适应性,特别是与其姐妹进化枝相比,sect.剖腹产.总的来说,A.教派的分布范围更广。阴道科,从泛热带到泛北极,提供了一个独特的窗口来了解跨物种丰富的ECM真菌进化枝的生态位保守主义。