國際著名期刊美國《國家科學院院刊》（PNAS）2月19日在線發(fā)表了中國科學院武漢植物園王恒昌博士和美國佛羅里達大學合作研究的研究論文：Rosid radiation and the rapid rise of angiosperm-dominated forests,。
現(xiàn)存大約30萬種的被子植物,，分為約15,000屬和400多科。理解這些類群的親緣關系是一個艱巨的任務,。本項研究通過多取樣,、多基因的策略，并采用基因序列同時比對可信的化石記錄的方法開展研究,。結果表明,，現(xiàn)存約三十萬種顯花植物的1/3組成的一個譜系，即Rosids（薔薇類）在9千萬年前曾經(jīng)歷了一次爆發(fā)式分化,，同時又引發(fā)了兩棲類,、螞蟻、哺乳動物,、蕨類等類群的適應輻射式物種形成,。該研究利用現(xiàn)存生物的分子證據(jù)，首次揭示了這些植物的進化關系,，為它們的快速形成和分化提供了依據(jù),。文章揭示出在一次爆發(fā)式分化中顯花植物的分化，形成了以被子植物為主體的森林系統(tǒng),，這些森林系統(tǒng)后來成為了各種有機體的棲息地,。研究結果對認識地球上生物類群間的親緣關系，以及理解特定空間區(qū)域內(nèi)物種的相互競爭關系也具有十分重要的指導意義,。(生物谷Bioon.com)
生物谷推薦原始出處：
PNAS,，doi: 10.1073/pnas.0813376106,，Hengchang Wang，Douglas E. Soltis
Rosid radiation and the rapid rise of angiosperm-dominated forests
Hengchang Wanga,b, Michael J. Moorec, Pamela S. Soltisd, Charles D. Belle, Samuel F. Brockingtonb, Roolse Alexandreb, Charles C. Davisf, Maribeth Latvisb,f, Steven R. Manchesterd and Douglas E. Soltisb,1
aWuhan Botanical Garden, The Chinese Academy of Science, Wuhan, Hubei 430074 China;
bDepartment of Botany and
dFlorida Museum of Natural History, University of Florida, Gainesville, FL 32611;
cBiology Department, Oberlin College, Oberlin, OH 44074-1097;
eDepartment of Biological Sciences, University of New Orleans, New Orleans, LA 70148; and
fDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138
Abstract
The rosid clade (70,000 species) contains more than one-fourth of all angiosperm species and includes most lineages of extant temperate and tropical forest trees. Despite progress in elucidating relationships within the angiosperms, rosids remain the largest poorly resolved major clade; deep relationships within the rosids are particularly enigmatic. Based on parsimony and maximum likelihood (ML) analyses of separate and combined 12-gene (10 plastid genes, 2 nuclear; >18,000 bp) and plastid inverted repeat (IR; 24 genes and intervening spacers; >25,000 bp) datasets for >100 rosid species, we provide a greatly improved understanding of rosid phylogeny. Vitaceae are sister to all other rosids, which in turn form 2 large clades, each with a ML bootstrap value of 100%: (i) eurosids I (Fabidae) include the nitrogen-fixing clade, Celastrales, Huaceae, Zygophyllales, Malpighiales, and Oxalidales; and (ii) eurosids II (Malvidae) include Tapisciaceae, Brassicales, Malvales, Sapindales, Geraniales, Myrtales, Crossosomatales, and Picramniaceae. The rosid clade diversified rapidly into these major lineages, possibly over a period of <15 million years, and perhaps in as little as 4 to 5 million years. The timing of the inferred rapid radiation of rosids [108 to 91 million years ago (Mya) and 107–83 Mya for Fabidae and Malvidae, respectively] corresponds with the rapid rise of angiosperm-dominated forests and the concomitant diversification of other clades that inhabit these forests, including amphibians, ants, placental mammals, and ferns.
