Strong phylogenetic signals and phylogenetic niche conservatism in ecophysiological traits across divergent lineages of Magnoliaceae.

Hui Liu,Qing Ye,Keming Yang,Qiuyuan Xu,Pengcheng He,Louis S Santiago

doi:10.1038/srep12246

Abstract

The early diverged Magnoliaceae shows a historical temperate-tropical distribution among lineages indicating divergent evolution, yet which ecophysiological traits are phylogenetically conserved, and whether these traits are involved in correlated evolution remain unclear. Integrating phylogeny and 20 ecophysiological traits of 27 species, from the four largest sections of Magnoliaceae, we tested the phylogenetic signals of these traits and the correlated evolution between trait pairs. Phylogenetic niche conservatism (PNC) in water-conducting and nutrient-use related traits was identified, and correlated evolution of several key functional traits was demonstrated. Among the three evergreen sections of tropical origin, Gwillimia had the lowest hydraulic-photosynthetic capacity and the highest drought tolerance compared with Manglietia and Michelia. Contrastingly, the temperate centred deciduous section, Yulania, showed high rates of hydraulic conductivity and photosynthesis at the cost of drought tolerance. This study elucidated the regulation of hydraulic and photosynthetic processes in the temperate-tropical adaptations for Magnoliaceae species, which led to strong phylogenetic signals and PNC in ecophysiological traits across divergent lineages of Magnoliaceae.

Highlights

Trait evolution model, it is difficult to infer the underlying evolutionary processes through analysis of phylogenetic signal[5,6,9]
Previous phylogenetic work suggested that the divergence time between two closely related lineages of Magnoliaceae separating into temperate (Yulania) and tropical (Michelia) areas was before the Oligocene[30,34]
The majority of plant traits tested in this study showed strong phylogenetic signals based on Pagel’s λ (λ > 0.50 and P < 0.05 for λ = 0), except Ψtlp, Aarea, gs, E, WUEi, leaf P and N/P; and Blomberg’s K of each trait showed congruent patterns as Pagel’s λ, except the lower absolute magnitude of K (Table 1)

Summary

Introduction

Trait evolution model, it is difficult to infer the underlying evolutionary processes through analysis of phylogenetic signal[5,6,9]. Considering the temperate-tropical distributions, we measured 20 ecophysiological traits related to resource use (mainly hydraulics and photosynthesis), and tested their phylogenetic signals and correlated evolution between trait pairs.

Results

Conclusion