Molecular phylogeny of Camphorosmeae (Camphorosmoideae, Chenopodiaceae): Implications for biogeography, evolution of C4-photosynthesis and taxonomy
Molecular phylogeny of Camphorosmeae (Camphorosmoideae, Chenopodiaceae): Implications for biogeography, evolution of C4-photosynthesis and taxonomy
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DOI：
10.1002/tax.601006
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发表时间：
2011-02-01
期刊：
影响因子：
3.4
通讯作者：
Freitag, Helmut
中科院分区：
文献类型：
--
作者：
Kadereit, Gudrun;Freitag, Helmut
樟亚科是藜科-樟亚科的一个物种丰富的族，主要由亚灌木和一年生植物组成，分布于澳大利亚、欧亚大陆、北非、南部非洲和北美的草原和半沙漠。利用5个不同标记（rbcL基因、ndhF基因、atpB-rbcL、spacer、pshB-psbH spacer、ITS）的序列变异和形态学特征，研究了樟亚科与猪毛菜亚科亲缘关系近的主要谱系的关系以及樟族的多样性，重点是非澳大利亚成员。cpDNA分析揭示了樟树亚科/猪毛菜亚科（Camphorosmeae，Salsoleae s.str.，结果表明，香樟亚科与猪毛菜属所有分支的姐妹群关系（ndhF和atpB-rbcL，spacer）均与猪毛菜属所有分支的姐妹群关系相一致。樟亚科与猪毛菜科的区别。种子、柱头和花粉形态进一步支持了这一观点。分子钟估计指向一个更早的辐射在Salsoleae s.l.（早至中渐新世）比Camphorosmeae（早中新世）。在Salsoleae s.l.早期的辐射可能是由于C-4光合作用的多重进化而增强的，这促进了向欧亚大陆干燥生境的传播。在樟亚科，C-4-光合作用可能进化了两次，可能是在中新世中期。在中新世期间，樟属植物从欧亚大陆传播到澳大利亚、北美，并至少两次传播到南非。只有澳大利亚血统多样化，其他人仍然物种贫乏。分子树一致地解决了三个主要的分支不清楚的关系樟亚科，Chenolea分支（五个广泛分离和形态分歧的C-3-物种，可能残留的老谱系），Sclerolaena分支（约。中亚150种C-3种[3种]和澳大利亚[147种]，可能是上新世快速辐射的结果）和Bassia/Camphorosma分支（约。23种C-4种和1种C-3/C-4中间种，广泛分布于欧亚大陆和南部非洲）。该分类系统显示了目前欧亚、北美和南非樟亚科属和亚族分类的人为状态。所有非单型属，除了樟属和Neokochia被发现是复系。本文提出了一个新的族分类，包括恢复新定义的樟亚科，描述新属螺菌属（Spirobassia，1种），Eokochia（1 sp.），Grubovia（3种）和Sedobassia（1 sp.），以及几种新的组合和同义词。
Camphorosmeae constitute a species-rich tribe of Chenopodiaceae-Camphorosmoideae that consists mostly of sub-shrubs and annuals, distributed in steppes and semi-deserts of Australia, Eurasia, North Africa, southern Africa and North America. We study (1) the relationships of Camphorosmeae to major lineages of the closely related Salsoloideae and (2) the diversification of the tribe with focus on the non-Australian members using sequence variation of five different markers (rbcL gene, ndhF gene, atpB-rbcL, spacer, pshB-psbH spacer, ITS) and morphological characters. The cpDNA analyses revealed six early-branching lineages in Camphorosmoideae/Salsoloideae (Camphorosmeae, Salsoleae s.str., Caroxyloneae Salsola kali clade, Nanophyton clade, Salsola genistoides clade) and supported partly (ndhF and atpB-rbcL, spacer) the sister-group relationship of Camphorosmeae and all Salsolean clades. The distinctness of Camphorosmeae and Salsoleae s.l. is further supported by seed, stigma and pollen morphology. Molecular clock estimates point to an earlier radiation in Salsoleae s.l. (Early to Middle Oligocene) than in Camphorosmeae (Early Miocene). In Salsoleae s.l. early radiation might have been enhanced by multiple evolution of C-4-photosynthesis which facilitated the spread into drier habitats of Eurasia. In Camphorosmeae, C-4-photosynthesis likely evolved two times, probably in the Middle Miocene. During the Miocene Camphorosmeae spread from Eurasia to Australia, North America and at least two times to South Africa. Only the Australian lineage diversified, the others remained species-poor. The molecular trees congruently resolve three major clades of unclear relationship within Camphorosmeae, Chenolea clade (five widely disjunct and morphologically divergent C-3-species, possibly remnants of old lineages), Sclerolaena clade (ca. 150 C-3-species from Central Asia [3 spp.] and Australia [147 spp.], probably the results of a rapid radiation during the Pliocene) and Bassia/Camphorosma clade (ca. 23 C-4-species and one C-3/C-4-intermediate which are widely distributed in Eurasia and southern Africa). The phylogenies show the artificial state of the current generic and subtribal classifications of Eurasian, North American and South African Camphorosmeae. All non-monotypic genera except Camphorosma and Neokochia were found to be polyphyletic. A revised classification of the tribe is proposed including reinstatement of the newly defined subfamily Camphorosmoideae, description of the new genera Spirobassia (1 sp.), Eokochia (1 sp.), Grubovia (3 spp.) and Sedobassia (1 sp.), and several new combinations and synonymizations.