| 1 | High universality of matK primers for barcoding gymnosperms显示文摘DNA barcoding is a tool to provide rapid and accurate taxonomic identification using a standard DNA region.A two-marker combination of matK+rbcL was formally proposed as the core barcode for land plants by the Consortium for the Barcode of Life Plant Working Group.However,there are currently no barcoding primers for matK showing high universality in gymnosperms.We used 57 gymnosperm species representing 40 genera,11 families and four subclasses to evaluate the universality of nine candidate matK primers and one rbcL primer in this study.Primer(1F/724R) of rbcL is proposed here as a universal primer for gymnosperms due to high universality.One of the nine candidate matK primers(Gym_F1A/Gym_R1A) is proposed as the best 'universal' matK primer for gymnosperms because of high polymerase chain reaction success and routine generation of high quality bidirectional sequences.A specific matK primer for Ephedra was newly designed in this study,which performed well on the sampled species.The primers proposed here for rbcL and matK can be easily and successfully amplified for most gymnosperms. | Yan LI Lian-Ming GAO Ram C. POUDEL De-Zhu Li Alan FORREST | 2011 | Journal of Systematics and Evolution2011，49，3： | 5 |
| 7 | Ecological and geological processes impacting speciation modes drive the formation of wide-range disjunctions within tribe Putorieae(Rubiaceae)显示文摘Abstract Wide-range geographically discontinuous distributions have long intrigued scientists.We explore the role of ecology,geology,and dispersal in the formation of these large-scale disjunctions,using the angiosperm tribe Putorieae(Rubiaceae)as a case study.From DNA sequences of nuclear ITS and six plastid markers,we inferred a phylogeny with 65%of all known Putorieae species.Divergence times,ancestral ranges,and diversification rate shifts were then estimated using Bayesian inference.We further explored species climatic tolerances and performed ancestral niche reconstruction to discriminate among alternative speciation modes,including geographical and ecological vicariance,and ecogeographical,ecological,and dispersal-mediated speciation.As a result,we identified seven major clades in Putorieae,some of which exhibit striking geographical disjunctions,matching the Rand Flora pattern,with sister species in the Canary Islands and eastern and southern Africa.Initial diversification within the tribe occurred in the early Miocene,coincident with a period of climate warming;however,most clades diverged within the last 10 Myr.Aridification and high extinction rates,coupled with ecological vicariance,explain the oldest disjunctions.Adaptation to new environmental conditions,after allopatry,is observed in several clades.Dispersal,either long-distance or via corridors made available by mountain uplift,is behind the most recent disjunctions.Some of these events were followed by ecological speciation and rapid diversification,with species becoming adapted to xeric or increasingly colder continental climates.We show that an integrative approach may help discriminate among speciation modes invoked to explain disjunctions at macroevolutionary time scales,even when extinction has erased the signature of past events. | Mario Rincon-Barrado Sanna Olsson Tamara Villaverde Belen Moncalvillo Lisa Pokorny Alan Forrest Ricarda Riina Isabel Sanmartin | 2021 | Journal of Systematics and Evolution2021，59，5： | 0 |
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