Zhe-Kun Zhou

Systematics of Fagaceae: Phylogenetic Tests of Reproductive Trait Evolution

The family Fagaceae includes nine currently recognized genera and ca. 1000 species, making it one of the largest and most economically important groups within the order Fagales. In addition to wide variation in cupule and fruit morphology, polymorphism in pollination syndrome (wind vs. generalistic insect) also contributes to the uniqueness of the family. Phylogenetic relationships were examined using 179 accessions spanning the taxonomic breadth of the family, emphasizing tropical, subtropical, and relictual taxa. Nuclear ribosomal DNA sequences encoding the 5.8S rRNA gene and two flanking internal transcribed spacers (ITS) were used to evaluate phylogenetic hypotheses based on previous morphological cladistic analysis and intuitive schemes. Parsimony analyses rooted with Fagus supported two clades within the family, Trigonobalanus sensu lato and a large clade comprising Quercus and the castaneoid genera ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

LEAF MARGIN ANALYSIS: A NEW EQUATION FROM HUMID TO MESIC FORESTS IN CHINA

Castanea+Castanopsis

Integrating fossils in a molecular-based phylogeny and testing them as calibration points for divergence time estimates in Menispermaceae

\end{document} , Chrysolepis, Lithocarpus). Three DNA sequence data sets, 179‐taxon ITS, 60‐taxon ITS, and a 14‐taxon combined nuclear and chloroplast (matK), were used to test a priori hypotheses of reproductive character state evolution. We used Templeton’s (1983) test to assess alternative scenarios of single and multiple origins of derived and seemingly irreversible traits such as wind pollination, hypogeal cotyledons, and flower cupules. On the basis of previous exemplar‐based and current in‐depth analyses of Fagaceae, we suggest that wind pollination evolved at least three times and hypogeal cotyledons once. Although we could not reject the hypothesis that the acorn fruit type of Quercus is derived from a dichasium cupule, combined analysis provided some evidence for a relationship of Quercus to Lithocarpus and Chrysolepis, taxa with dichasially arranged pistillate flowers, where each flower is surrounded by cupular tissue. This indicates that a more broadly defined flower cupule, in which individual pistillate flowers seated within a separate cupule, may have a single origin.

Phylogeographic analysis reveals significant spatial genetic structure of Incarvillea sinensis as a product of mountain building

Incarvillea is a herbaceous and temperate member of Bignoniaceae, previously divided into four subgenera, Niedzwedzkia, Amphicome, Incarvillea, and Pteroscleris. Niedzwedzkia and Amphicome have in the past been treated as independent genera. Different relationships have been proposed for the four subgenera. Here, maximum parsimony analysis using ITS and trnL-F sequences resulted in similar trees and showed that the genus is monophyletic. Analysis of the combined data resulted in a single tree with five major clades highly supported and well resolved. The relationships of the five major clades are (subgenus Niedzwedzkia (Incarvillea olgae (subgenus Amphicome (subgenus Incarvillea, subgenus Pteroscleris)))). All four subgenera are well supported for monophyly, with the exception of subgenus Incarvillea, represented here by I. sinensis and I. olgae. Incarvillea olgae is not closely related to I. sinensis, a conclusion supported by morphology. The two basal monotypic subgenera are found in Central Asia. The most species-rich subgenus, Pteroscleris, has 10 species in the Himalaya-Hengduan Mountains and may have dispersed early from central Asia to eastern Asia. Short branch lengths on the molecular trees within Pteroscleris suggest a recent and rapid radiation of this rosette-forming subgenus, perhaps connected with the uplift of the Himalaya-Hengduan massif.

Taxonomic and ecological implications of leaf cuticular morphology in Castanopsis, Castanea, and Chrysolepis

Abstract Leaf margin analysis (LMA) is a widely used method that applies present-day linear correlation between the proportion of woody dicotyledonous species with untoothed leaves (P) and mean annual temperature (MAT) to estimate paleotemperatures from fossil leaf floras. Previous works demonstrate that LMA shows regional constraints and to date, no equation has been modeled directly from Chinese forests. Fifty humid to mesic Chinese forests were chosen to understand the relationship between percentage of untoothed leaf species and MAT in China. Consistent with previous studies, the Chinese data indicate that P shows a strong linear correlation with MAT, but the actual relationship is a little different from those recognized from other regions. Among the several currently used LMA equations, the one resulting from North and Central American and Japanese data, rather than the widely used East Asian LMA equation, yields the closest values to the actual MATs of the Chinese samples (mean absolute error = 1.9 °C). A new equation derived from the Chinese forests is therefore developed, where MAT = 1.038 + 27.6 × P. This study not only demonstrates the similarity of the relationship between P and MAT in the Northern Hemisphere, but also improves the reliability of LMA for paleoclimate reconstructions of Chinese paleofloras.

Parasitic loranthus from Loranthaceae rather than Viscaceae potently inhibits fatty acid synthase and reduces body weight in mice

The evolution of plant ecosystems during the Cenophytic was complex and influenced by both abiotic and biotic factors. Among abiotic forces were tectonics, the distribution of continents and seas, climate, and fires; of biotic factors were herbivores, pests, and intra- and interspecific competition. The genus Quercus L. (Quercoideae, Fagaceae) evolved in this context to become an established member of the plant communities of the Northern Hemisphere, commencing in the Paleogene and spreading to a diverse range of environments in the later Cenozoic. Its palaeontological record, dominated by leaves and pollen, but also including wood, fruits and flowers, is widespread in Eurasia and North America. Consequently, a great number of species have been described, from the 19th century to the present day. Although Quercus is currently an ecologically and economically important component of the forests in many places of the Northern Hemisphere and Southeastern Asia, no comprehensive summary of its fossil record exists. The present work, written by an international team of palaeobotanists, provides the first synthesis of the fossil history of the oaks from their appearance in the early Paleogene to the Quaternary.

First Fossil Fruits and Leaves of Burretiodendron s.l. (Malvaceae s.l.) in Southeast Asia: Implications for Taxonomy, Biogeography, and Paleoclimate

Abstract  The phylogeny of extant Menispermaceae (Ranunculales) is reconstructed based on DNA sequences of two chloroplast genes (rbcL and atpB) from 94 species belonging to 56 genera. Fossilized endocarps represent 34 genera. The positions of these are inferred using 30 morphological characters and the molecular phylogeny as a backbone constraint. Nine of the thirteen nodes that are each dated by a fossil are used as calibration points for the estimates of molecular divergence times. BEAST is used to estimate stem age (121.2 Myr) and crown age (105.4 Myr) for Menispermaceae. This method does not require an input tree topology and can also account for rate heterogeneity among lineages. The sensitivity of these estimates to fossil constraints is then evaluated by a cross‐validation procedure. The estimated origin for Menispermaceae is dated to the mid‐Jurassic if the customary maximum age of 125 Myr for eudicots is not implemented. All constraints when used alone failed to estimate node ages in some parts of the tree. Fossils from the Palaeocene and Eocene impose strict constraints. Likewise, the use of Prototinomiscium as a dating constraint for Menispermaceae appears to be a conservative approach.

Rates of Water Loss and Uptake in Recalcitrant Fruits of Quercus Species Are Determined by Pericarp Anatomy

BackgroundIncarvillea sinensis is widely distributed from Southwest China to Northeast China and in the Russian Far East. The distribution of this species was thought to be influenced by the uplift of the Qinghai-Tibet Plateau and Quaternary glaciation. To reveal the imprints of geological events on the spatial genetic structure of Incarvillea sinensis, we examined two cpDNA segments ( trnH- psbA and trnS- trnfM) in 705 individuals from 47 localities.ResultsA total of 16 haplotypes was identified, and significant genetic differentiation was revealed (GST =0.843, NST = 0.975, P < 0.05). The survey detected two highly divergent cpDNA lineages connected by a deep gap with allopatric distributions: the southern lineage with higher genetic diversity and differentiation in the eastern Qinghai-Tibet Plateau, and the northern lineage in the region outside the Qinghai-Tibet Plateau. The divergence between these two lineages was estimated at 4.4 MYA. A correlation between the genetic and the geographic distances indicates that genetic drift was more influential than gene flow in the northern clade with lower diversity and divergence. However, a scenario of regional equilibrium between gene flow and drift was shown for the southern clade. The feature of spatial distribution of the genetic diversity of the southern lineage possibly indicated that allopatric fragmentation was dominant in the collections from the eastern Qinghai-Tibet Plateau.ConclusionsThe results revealed that the uplift of the Qinghai-Tibet Plateau likely resulted in the significant divergence between the lineage in the eastern Qinghai-Tibet Plateau and the other one outside this area. The diverse niches in the eastern Qinghai-Tibet Plateau created a wide spectrum of habitats to accumulate and accommodate new mutations. The features of genetic diversity of populations outside the eastern Qinghai-Tibet Plateau seemed to reveal the imprints of extinction during the Glacial and the interglacial and postglacial recolonization. Our study is a typical case of the significance of the uplift of the Qinghai-Tibet Plateau and the Quaternary Glacial in spatial genetic structure of eastern Asian plants, and sheds new light on the evolution of biodiversity in the Qinghai-Tibet Plateau at the intraspecies level.