MOLECULAR PHYLOGENETIC ANALYSIS OF THE PERSEA GROUP (LAURACEAE) AND ITS BIOGEOGRAPHIC IMPLICATIONS ON THE EVOLUTION OF TROPICAL AND SUBTROPICAL AMPHI-PACIFIC DISJUNCTIONS
MOLECULAR PHYLOGENETIC ANALYSIS OF THE PERSEA GROUP (LAURACEAE) AND ITS BIOGEOGRAPHIC IMPLICATIONS ON THE EVOLUTION OF TROPICAL AND SUBTROPICAL AMPHI-PACIFIC DISJUNCTIONS
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DOI：
10.3732/ajb.1100006
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发表时间：
2011-09-01
影响因子：
3
通讯作者：
Li, Hsi-Wen
中科院分区：
文献类型：
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作者：
Li, Lang;Li, Jie;Li, Hsi-Wen
研究的前提:Persea集团(樟科)有一个热带和亚热带amphi-pacific分离的分布与大部分的成员,它包括两个Macaronesian物种。该群体内部的关系仍然存在争议，其洲际分离尚未通过广泛的抽样和精确的时间测定进行调查。方法：采用最大简约法和贝叶斯推理对78种紫杉属植物和9种樟科植物的ITS和LEAFY内含子II序列进行分析。散度时间估计采用松弛时钟下的贝叶斯马尔可夫链蒙特卡罗方法。关键结果：除Alseodaphne和Dehaasia外，Persea类群内的几个传统属或亚属形成了良好的单系类群。据估计，波斯群的分化时间与55.3亿年前（mya）相似（95%高后验密度[HPD] 4140 - 6990）。Persea组的两个主要差异估计为51.9 （95% HPD 38.9-63.9）兆年和48.5 （95% HPD 35.9-59.9）兆年。结论：波斯属可以保留为一个属，包括阿波罗尼亚巴布亚纳，并排除一些不适合建立亚属的种。建议对Alseodaphne， Dehaasia和Nothaphoebe之间的划分进行重大修订。我们认为Persea群起源于始新世早期Laurasia的Perseeae-Laureae辐射。始新世中后期气候变冷对北热带植物群的破坏是其两太平洋分离的结果。美洲-马卡罗尼西亚的分离可以用远距离分散来解释。
Premise of the study: The Persea group (Lauraceae) has a tropical and subtropical amphi-pacific disjunct distribution with most of its members, and it includes two Macaronesian species. The relationships within the group are still controversial, and its intercontinental disjunction has not been investigated with extensive sampling and precise time dating.Methods: ITS and LEAFY intron II sequences of 78 Persea group species and nine other Lauraceae species were analyzed with maximum parsimony and Bayesian inference. Divergence time estimation employed Bayesian Markov chain Monte Carlo method under a relaxed clock.Key results: Several traditional genera or subgenera within the Persea group form well-supported monophyletic groups except Alseodaphne and Dehaasia. The divergence time of the Persea group is estimated as similar to 55.3 (95% higher posterior densities [HPD] 41.4-69.9) million years ago (mya). Two major divergences within the Persea group are estimated as similar to 51.9 (95% HPD 38.9-63.9) mya and similar to 48.5 (95% HPD 35.9-59.9) mya.Conclusions: Persea can be retained as a genus by the inclusion of Apollonias barbujana and exclusion a few species that do not fit into the established subgenera. A major revision is recommended for the delimitation between Alseodaphne, Dehaasia, and Nothaphoebe. We suggest that the Persea group originated from the Perseeae-Laureae radiation in early Eocene Laurasia. Its amphi-pacific disjunction results from the disruption of boreotropical flora by climatic cooling during the mid-to late Eocene. The American-Macaronesian disjunction may be explained by the long-distance dispersal.