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The diverse and pantropical genus Ctenitis, in the Dryopteridaceae, has been largely ignored in phylogenetic studies until now. In this study, we fill in this gap by reconstructing the first comprehensive phylogeny of the genus including 53 species currently recognized in the genus Ctenitis, among which seven species formerly were assigned to the genus Pseudotectaria and one to Heterogonium. Special emphasis was given to the sampling of species occurring in the African-Indian Ocean region. The presented results include reconstruction of a biogeographic scenario based on estimated divergence times and ancestral area reconstruction. Our findings confirm the inclusion, within Ctenitis, of the Indian Ocean species formerly placed in Pseudotectaria and Heterogonium. The crown group divergence was estimated to date back to the Oligocene or Early Miocene. The biogeographical scenario indicates an initial divergence of the Asian-Pacific ranges and the neotropical ranges, and a subsequent colonization of the Afro-Madagascan region by a lineage with neotropical ancestors. The Afro-Madagascan lineage splits into a lineage endemic to the Mascarene islands and a lineage occurring in Madagascar, the Comoros and Africa. The range expansion towards Africa and Madagascar was estimated to date back to the late Miocene, whereas the estimated ages for the onset of the diversification of the Mascarene diversity is consistent with the ages of these young, volcanic islands. The absence of any extant species of Ctenitis with a multi-continental distribution range and the rarity of inter-island dispersal and speciation in the Indian Ocean region suggest a limited contribution of long distance dispersal to the biogeographical history of this fern genus, versus a high contribution of local speciation., (Copyright © 2017. Published by Elsevier Inc.)

Cerasus serrulata (Rosaceae) is an important flowering cherry resource which is valuable for developing new cultivars of flowering cherries. It is broadly distributed and possesses abundant variations. In this study, phylogeographic analysis was conducted to reveal the evolutionary history to better understand the genetic diversity and genetic structure of C. serrulata so as to provide more accurate molecular insights into better conservation and utilization of the germplasm resources. A total of 327 individuals from 18 wild populations were collected. Three chloroplast DNA (cpDNA) fragments (matK, trnD‐E, and trnS‐G) and the nuclear internal transcribed spacer (ITS) were utilized. The results showed a high genetic diversity at both species level and population level of C. serrulata. High genetic differentiation and the existence of the phylogeographic structure were detected. No significant expansion events were discovered. Two geographic lineages were inferred. One was confined to the Qinling Mountains and the Taihang Mountains. The other was from the Wuling Mountains to the Jiangnan Hilly Regions and then went northeast to the coast of Asia. In addition, some taxonomic treatments of the C. serrulata complex are discussed and reconsidered. Conservation and utilization strategies of wild C. serrulata germplasm resources were recommended. [ABSTRACT FROM AUTHOR]

Cerasus dielsiana (Rosaceae) is one of the most characteristic wild flowering cherry species endemic to subtropical China, with high conservation value from ornamental, economic, and ecological perspectives. To verify its spatial genetic structure and phylogeographic history, evaluation of nuclear (ITS) sequence variation in 203 individuals from 25 wild populations across its natural distribution ranges was conducted. High levels of ribotypes and nuclear diversity (Hd = 0.879 ± 0.012, π = 3.56 ± 0.16) were detected at the species level. Spatial analysis of molecular variation (SAMOVA), median-joining network and phylogenetic Neighbour-joining tree assigned the populations into four genetically distinct groups. Meanwhile, high levels of genetic differentiation among populations and strong phylogeographic patterns (Nst = 0.837 > Gst = 0.585; P < 0.05) were revealed based on the analysis of molecular variance (AMOVA). Results of neutrality tests, mismatch distribution analyses, Mantel test, barrier analyses, together with ecological niche modelling (ENM) simulation and BEAST analysis suggest a long-term demographic history (95% HPD: 3.64–8.83 Mya) of C. dielsiana, and at least three potential in situ glacial refugia as well as recent demographic expansion in eastern region have been detected. Collectively, we highlight that the combined effect of natural selection and random genetic drift under complex topography and palaeoclimatic oscillations since the Last Glacial Maximum (LGM) in subtropical China might have been the main driver to the species' allopatric differentiation. Scientific conservation and sustainable utilization for wild C. dielsiana germplasm resources were subsequently proposed. [ABSTRACT FROM AUTHOR]