Limits...
Phylogeny and biogeography of Primula sect. Armerina: implications for plant evolution under climate change and the uplift of the Qinghai-Tibet Plateau.

Ren G, Conti E, Salamin N - BMC Evol. Biol. (2015)

Bottom Line: However, their effects on dispersal, differentiation and evolution of many groups of plants are still unknown.Our results support the hypothesis that geologic and climatic events play important roles in driving biological diversification of organisms in the QTP area.Armerina.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland. guangpeng.ren@unil.ch.

ABSTRACT

Background: The historical orogenesis and associated climatic changes of mountain areas have been suggested to partly account for the occurrence of high levels of biodiversity and endemism. However, their effects on dispersal, differentiation and evolution of many groups of plants are still unknown. In this study, we examined the detailed diversification history of Primula sect. Armerina, and used biogeographic analysis and macro-evolutionary modeling to investigate a series of different questions concerning the evolution of the geographical and ecological distribution of the species in this section.

Results: We sequenced five chloroplast and one nuclear genes for species of Primula sect. Armerina. Neither chloroplast nor nuclear trees support the monophyly of the section. The major incongruences between the two trees occur among closely related species and may be explained by hybridization. Our dating analyses based on the chloroplast dataset suggest that this section began to diverge from its relatives around 3.55 million years ago, largely coinciding with the last major uplift of the Qinghai-Tibet Plateau (QTP). Biogeographic analysis supports the origin of the section in the Himalayan Mountains and dispersal from the Himalayas to Northeastern QTP, Western QTP and Hengduan Mountains. Furthermore, evolutionary models of ecological niches show that the two P. fasciculata clades have significantly different climatic niche optima and rates of niche evolution, indicating niche evolution under climatic changes and further providing evidence for explaining their biogeographic patterns.

Conclusion: Our results support the hypothesis that geologic and climatic events play important roles in driving biological diversification of organisms in the QTP area. The Pliocene uplift of the QTP and following climatic changes most likely promoted both the inter- and intraspecific divergence of Primula sect. Armerina. This study also illustrates how niche evolution under climatic changes influences biogeographic patterns.

Show MeSH
The maximum clade credibility (MCC) tree derived from MrBayes analyses of the nuclear dataset. Maximum likelihood (ML) bootstrap values and Bayesian posterior probabilities (PP) are indicated at major nodes. Bootstrap values ≥ 80 and PP ≥ 0.95 are indicated with thicker branches. Outgroup species are shown in bold. Two nuclear gene copies for some samples are indicated with “-1” or “-2”
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4537560&req=5

Fig3: The maximum clade credibility (MCC) tree derived from MrBayes analyses of the nuclear dataset. Maximum likelihood (ML) bootstrap values and Bayesian posterior probabilities (PP) are indicated at major nodes. Bootstrap values ≥ 80 and PP ≥ 0.95 are indicated with thicker branches. Outgroup species are shown in bold. Two nuclear gene copies for some samples are indicated with “-1” or “-2”

Mentions: In contrast to the plastid dataset, Primula sect. Armerina and two nested outgroup species received very high node support (PP 1.0, ML 100 %) in the nrDNA phylogenetic tree, but the relationships between species were less well supported (Fig. 3). Three main clades within the section identified in the chloroplast tree were also inferred in the nuclear tree (Fig. 3). The clade involucrata was well-supported (PP 1.0, ML 86 %), while the clades conspersa (except for P. farinosa, P. mistassinica and P. egaliksensis) and pumilio received very weak nodal support in both types of analyses. The relationships within each clade were further incongruent between the trees obtained by the two datasets. Primula fasciculata was divided into three clades in the nrDNA tree (Fig. 3). One clade included samples from P. fasciculata that cluster with a moderately supported clade representing P. involucrata. A second clade included all samples of P. tibetica and P. fasciculata and one copy of P. fasciculata. Finally, the third clade included all samples of P. nutans and P. pamirica, one copy of P. egaliksensis and the remaining samples of P. fasciculata (Fig. 3). Similarly, P. gemmifera separated into two groups, either with P. zambalensis or in a clade including all samples of P. conspersa (Fig. 3). Two copies of P. egaliksensis were clustered with either P. nutans or P. mistassinica, corroborating the hypothesis of the allopolyploid origin of this species [35–37].Fig. 3


Phylogeny and biogeography of Primula sect. Armerina: implications for plant evolution under climate change and the uplift of the Qinghai-Tibet Plateau.

Ren G, Conti E, Salamin N - BMC Evol. Biol. (2015)

The maximum clade credibility (MCC) tree derived from MrBayes analyses of the nuclear dataset. Maximum likelihood (ML) bootstrap values and Bayesian posterior probabilities (PP) are indicated at major nodes. Bootstrap values ≥ 80 and PP ≥ 0.95 are indicated with thicker branches. Outgroup species are shown in bold. Two nuclear gene copies for some samples are indicated with “-1” or “-2”
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4537560&req=5

Fig3: The maximum clade credibility (MCC) tree derived from MrBayes analyses of the nuclear dataset. Maximum likelihood (ML) bootstrap values and Bayesian posterior probabilities (PP) are indicated at major nodes. Bootstrap values ≥ 80 and PP ≥ 0.95 are indicated with thicker branches. Outgroup species are shown in bold. Two nuclear gene copies for some samples are indicated with “-1” or “-2”
Mentions: In contrast to the plastid dataset, Primula sect. Armerina and two nested outgroup species received very high node support (PP 1.0, ML 100 %) in the nrDNA phylogenetic tree, but the relationships between species were less well supported (Fig. 3). Three main clades within the section identified in the chloroplast tree were also inferred in the nuclear tree (Fig. 3). The clade involucrata was well-supported (PP 1.0, ML 86 %), while the clades conspersa (except for P. farinosa, P. mistassinica and P. egaliksensis) and pumilio received very weak nodal support in both types of analyses. The relationships within each clade were further incongruent between the trees obtained by the two datasets. Primula fasciculata was divided into three clades in the nrDNA tree (Fig. 3). One clade included samples from P. fasciculata that cluster with a moderately supported clade representing P. involucrata. A second clade included all samples of P. tibetica and P. fasciculata and one copy of P. fasciculata. Finally, the third clade included all samples of P. nutans and P. pamirica, one copy of P. egaliksensis and the remaining samples of P. fasciculata (Fig. 3). Similarly, P. gemmifera separated into two groups, either with P. zambalensis or in a clade including all samples of P. conspersa (Fig. 3). Two copies of P. egaliksensis were clustered with either P. nutans or P. mistassinica, corroborating the hypothesis of the allopolyploid origin of this species [35–37].Fig. 3

Bottom Line: However, their effects on dispersal, differentiation and evolution of many groups of plants are still unknown.Our results support the hypothesis that geologic and climatic events play important roles in driving biological diversification of organisms in the QTP area.Armerina.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology and Evolution, Biophore, University of Lausanne, 1015, Lausanne, Switzerland. guangpeng.ren@unil.ch.

ABSTRACT

Background: The historical orogenesis and associated climatic changes of mountain areas have been suggested to partly account for the occurrence of high levels of biodiversity and endemism. However, their effects on dispersal, differentiation and evolution of many groups of plants are still unknown. In this study, we examined the detailed diversification history of Primula sect. Armerina, and used biogeographic analysis and macro-evolutionary modeling to investigate a series of different questions concerning the evolution of the geographical and ecological distribution of the species in this section.

Results: We sequenced five chloroplast and one nuclear genes for species of Primula sect. Armerina. Neither chloroplast nor nuclear trees support the monophyly of the section. The major incongruences between the two trees occur among closely related species and may be explained by hybridization. Our dating analyses based on the chloroplast dataset suggest that this section began to diverge from its relatives around 3.55 million years ago, largely coinciding with the last major uplift of the Qinghai-Tibet Plateau (QTP). Biogeographic analysis supports the origin of the section in the Himalayan Mountains and dispersal from the Himalayas to Northeastern QTP, Western QTP and Hengduan Mountains. Furthermore, evolutionary models of ecological niches show that the two P. fasciculata clades have significantly different climatic niche optima and rates of niche evolution, indicating niche evolution under climatic changes and further providing evidence for explaining their biogeographic patterns.

Conclusion: Our results support the hypothesis that geologic and climatic events play important roles in driving biological diversification of organisms in the QTP area. The Pliocene uplift of the QTP and following climatic changes most likely promoted both the inter- and intraspecific divergence of Primula sect. Armerina. This study also illustrates how niche evolution under climatic changes influences biogeographic patterns.

Show MeSH