Histolocalization of chemotaxonomic markers in Brazilian Vernonieae (Asteraceae)

Vernonieae are well represented in South America by subtribe Lychnophorinae, with 104 Brazilian species, some of them rare and endangered. Lychnophorinae are well known for producing metabolites of high pharmaceutical and chemotaxonomic value. Despite the importance of secondary metabolites in Lychnophorinae, there is still little evidence regarding the secretory structures responsible for producing these compounds. Therefore, in this study we investigated 15 species representative of the main lineages of Lychnophorinae, with the following objectives: to identify where the chemotaxonomic markers of Lychnophorinae are secreted and stored and in which developmental stage of the organ these metabolites are found. Samples of stems and leaves were processed according to the usual techniques in plant anatomy. It was found that the main sites of secondary metabolite biosynthesis are glandular trichomes, epidermal cells and parenchyma tissues. Metabolites from glandular trichomes, especially sesquiterpene lactones (STL), are prevalent in the early developmental stages of organs. The metabolite compounds stored in parenchyma tissues are mainly terpenoids, flavonoids and other phenolic compounds; young and expanded leaves are equally rich in metabolites. Thus, the information obtained in this study is essential for conducting chemotaxonomic studies in this group, helping to promote selective collection and conservation of species.     

Evolution of Stem and Leaf Structural Diversity: a Case Study in Lychnophorinae (Asteraceae)

Lychnophorinae occurs mainly in campos rupestres and cerrados of the Cerrado Domain (Brazil) and are species subject to fire occurrences and intense solar radiation, occupying acid and well-drained soils. Informative characters on the taxonomy of this subtribe were studied considering the leaf and stem morphology and anatomy. In addition, putative synapomorphies and features that probably determined the success of these species in occupying these habitats were identified. Samples of leaves and stems of 52 species were analyzed using usual techniques in plant anatomy. The reconstruction of ancestral states of characters was made in parsimony analysis using the phylogeny established for Lychnophorinae. The analyses indicated two distinct types of stems and a wide variation in foliar features, with the possible occurrence of three synapomorphies for the stems and 11 for the leaves. Adaptive pressures of restricted environments, where most species live, probably directed the evolution of morphological and anatomical diversity in Lychnophorinae.     

Chemometric evaluation of the anti-cancer pro-drug podophyllotoxin and potential therapeutic analogues in Juniperus and Podophyllum species

Introduction – Podophyllotoxin, deoxypodophyllotoxin, demethylpodophyllotoxin and podophyllotoxone are four therapeutically potent secondary metabolites. There is a dearth of information on the holistic analysis of their distribution pattern in both phylogenetic and ecological contexts. Objectives – To analyse the continuum of the above metabolites in Juniperus and Podophyllum species collected from natural populations in Himalayan environments and the botanical gardens of Rombergpark and Haltern (Germany) using multi‐component LC‐ESI‐MS/MS, coupled with statistically relevant chemometric assessment. Methodology – We evaluated the individual and holistic metabolite profiles and chemometrically correlated the phytochemical loads between various species (infraspecific), organic and aqueous extracts, and populations of the same species from different locations, different species from same location, different species from different locations and infrageneric populations from same and different locations. Results – Multivariate analysis revealed Juniperus x‐media Pfitzeriana as a suitable alternative to Podophyllum hexandrum for commercial exploitation. A significant positive correlation of podophyllotoxone with both podophyllotoxin and demethylpodophyllotoxin, and a negative correlation of podophyllotoxin with both deoxypodophyllotoxin and demethylpodophyllotoxin (infraspecific among Podophyllum), were observed by Kruskal's multidimensional scaling and corroborated by principal component analysis, indicating probable similarity and/or difference between the biosynthetic pathways, and synergistic and/or antagonistic principles, respectively. Finally, linear discriminant analysis and hierarchical agglomerative cluster analysis revealed considerable infrageneric and infraspecific variability in secondary compound spectra and load of the different populations under study. Conclusion – Such holistic studies of plants and their therapeutic metabolites ought to assist in selecting plants, geographical areas and environmental conditions for bioprospecting and global‐scale phytochemical and phylogenetic diversity studies in the future. Copyright © 2010 John Wiley & Sons, Ltd.     

Rapid maximum likelihood ancestral state reconstruction of continuous characters: A rerooting‐free algorithm

Ancestral state reconstruction is a method used to study the evolutionary trajectories of quantitative characters on phylogenies. Although efficient methods for univariate ancestral state reconstruction under a Brownian motion model have been described for at least 25 years, to date no generalization has been described to allow more complex evolutionary models, such as multivariate trait evolution, non‐Brownian models, missing data, and within‐species variation. Furthermore, even for simple univariate Brownian motion models, most phylogenetic comparative R packages compute ancestral states via inefficient tree rerooting and full tree traversals at each tree node, making ancestral state reconstruction extremely time‐consuming for large phylogenies. Here, a computationally efficient method for fast maximum likelihood ancestral state reconstruction of continuous characters is described. The algorithm has linear complexity relative to the number of species and outperforms the fastest existing R implementations by several orders of magnitude. The described algorithm is capable of performing ancestral state reconstruction on a 1,000,000‐species phylogeny in fewer than 2 s using a standard laptop, whereas the next fastest R implementation would take several days to complete. The method is generalizable to more complex evolutionary models, such as phylogenetic regression, within‐species variation, non‐Brownian evolutionary models, and multivariate trait evolution. Because this method enables fast repeated computations on phylogenies of virtually any size, implementation of the described algorithm can drastically alleviate the computational burden of many otherwise prohibitively time‐consuming tasks requiring reconstruction of ancestral states, such as phylogenetic imputation of missing data, bootstrapping procedures, Expectation‐Maximization algorithms, and Bayesian estimation. The described ancestral state reconstruction algorithm is implemented in the Rphylopars functions anc.recon and phylopars.     

The Phenolics of the Ornithogalum umbellatum L. (Hyacinthaceae): Phytochemical and Ecological Characterization

Ornithogalum umbellatum L. is a widely distributed species in Europe, that exhibits considerable variability at ecological, morphological, anatomical, and karyological level. Previous reports of the chemical investigations among Ornithogalum species indicate significant diversity of the secondary metabolites, as well. Knowing that environment affects the phenolic composition in plants to a large extent, the main objective of the research was to define relationship between phytochemical and ecological characters. To estimate an environmental influence on these results, plant material was collected at four habitats that differ in ecological factors and belong to two biogeographical regions: the Balkan Peninsula and the Pannonian Plane. Measured phytochemical characters are yield of dry extract, total phenolic and flavonoid contents, the presence of selected phenolic compounds as well as free‐radical scavenging activity (neutralization of DPPH and OH radicals). Results revealed that all analyzed phytochemical parameters differ between investigated O. umbellatum samples. The moisture level of habitat has the highest correlation, either positive or negative, with most of phytochemical characters, and is followed by temperature and soil reaction. Light intensity and nitrogen level have mostly moderate correlation coefficient with phytochemical characters. More complex correlation is revealed between ecological factors and nine phenolic compounds, with three observed patterns of relationship.     

Phytochemical diversity impacts herbivory in a tropical rainforest tree community

Metabolomics provides an unprecedented window into diverse plant secondary metabolites that represent a potentially critical niche dimension in tropical forests underlying species coexistence. Here, we used untargeted metabolomics to evaluate chemical composition of 358 tree species and its relationship with phylogeny and variation in light environment, soil nutrients, and insect herbivore leaf damage in a tropical rainforest plot. We report no phylogenetic signal in most compound classes, indicating rapid diversification in tree metabolomes. We found that locally co-occurring species were more chemically dissimilar than random and that local chemical dispersion and metabolite diversity were associated with lower herbivory, especially that of specialist insect herbivores. Our results highlight the role of secondary metabolites in mediating plant–herbivore interactions and their potential to facilitate niche differentiation in a manner that contributes to species coexistence. Furthermore, our findings suggest that specialist herbivore pressure is an important mechanism promoting phytochemical diversity in tropical forests.     

Microbial metabolomics: essential definitions and the importance of cultivation conditions for utilizing Bacillus species as bionematicides

Root-knot nematodes are destructive phytopathogens that damage agricultural crops globally, and there is growing interest in the use of biocontrol based on rhizobacteria such as Bacillus to combat Meloidogyne species. It is hypothesized that nematicidal activity of Bacillus can be attributed to the production of secondary metabolites and hydrolytic enzymes. Yet, few studies have characterized these metabolites and their identities remain unknown. Others are speculative or fail to elaborate on how secondary metabolites were detected or distinguished from primary metabolites. Metabolites can be classified based on their origin as either intracellular or extracellular and based on their function, as either primary or secondary. Although this classification is in general use, the boundaries are not always well defined. An understanding of the secondary metabolite and hydrolytic enzyme classification of Bacillus species will facilitate investigations aimed at bionematicide development. This review summarizes the significance of Bacillus hydrolytic enzymes and secondary metabolites in bionematicide research and provides an overview of known classifications. The importance of appropriate cultivation conditions for optimum metabolite and enzyme production is also discussed. Finally, the use of metabolomics for the detection and identification of nematicidal compounds is considered.     

Medicinal plants used in Jeddah,Saudi Arabia: Phytochemical screening

Ethnobotanical and phytochemical studies are useful to discover new drugs. Phytochemical screening is an important step in the detection of the bioactive components existing in medicinal plants that are used in traditional medicine. Very few phytochemical studies investigating medicinal plants used in traditional medicine exist in Saudi Arabia. Eighty-five medicinal plants used in traditional medicine in Jeddah, Saudi Arabia are investigated here for the first time. This research aims to screen of 85 medicinal plants used in traditional medicine in Jeddah for the presence of secondary metabolites, and to answer the following question: Is the ethnomedicinal importance of medicinal plants used in Jeddah conform to their secondary metabolite content. Ethnobotanical fieldwork took place in Jeddah from August 2018 to September 2019. Eighty-five different plant species belonging to 37 families were identified. Screening of 85 medicinal plants was performed for the presence of alkaloids, glycosides, flavonoids, tannins, saponins and resins using standard methods. The most commonly distributed phytochemical compounds among medicinal plants used were glycosides (82%; 70 species), tannins (68%; 58 species), alkaloids (56%; 48 species), saponins (52%, 44 species) and flavonoids (35%; 30 species). On the other hand, the least commonly distributed compounds were resins (31%; 26 species). All the six groups of secondary metabolites were found in seeds of Cuminum cyminum L., Pimpinella anisum L. and Trigonella foenum-graecum L. It can be said that the ethnomedicinal importance of these 85 medicinal plants used in Jeddah conform to their secondary metabolite content. More research should be carried out on the quantitative analysis of phytochemicals in these 85 medicinal plants used in traditional medicine in Jeddah. Furthermore, there is a need to focus phytochemical screening on ethnobotanical studies to complete research into traditional medicine which leads to the discovery of new drugs.     

Dynamic colonization exchanges between continents and islands drive diversification in paradise‐flycatchers (Terpsiphone,Monarchidae)

Aim We use parametric biogeographical reconstruction based on an extensive DNA sequence dataset to characterize the spatio‐temporal pattern of colonization of the Old World monarch flycatchers (Monarchidae). We then use this framework to examine the role of dispersal and colonization in their evolutionary diversification and to compare plumages between island and continental Terpsiphone species. Location Africa, Asia and the Indian Ocean. Methods We generate a DNA sequence dataset of 2300 bp comprising one nuclear and three mitochondrial markers for 89% (17/19) of the Old World Monarchidae species and 70% of the Terpsiphone subspecies. By applying maximum likelihood and Bayesian phylogenetic methods and implementing a Bayesian molecular clock to provide a temporal framework, we reveal the evolutionary history of the group. Furthermore, we employ both Lagrange and Bayes‐ Lagrange analyses to assess ancestral areas at each node of the phylogeny. By combining the ancestral area reconstruction with information on plumage traits we are able to compare patterns of plumage evolution on islands and continents. Results We provide the first comprehensive molecular phylogenetic reconstruction for the Old World Monarchidae. Our phylogenetic results reveal a relatively recent diversification associated with several dispersal events within this group. Moreover, ancestral area analyses reveal an Asian origin of the Indian Ocean and African clades. Ancestral state reconstruction analyses of plumage characters provide an interpretation of the plumage differentiation on islands and continents. Ancestral plumage traits are inferred to be close to those of the Asian paradise‐flycatcher (Terpsiphone paradisi), and island species display a high degree of plumage autapomorphy compared with continental species. Main conclusions Terpsiphone paradisi is polyphyletic and comprises populations that have retained the ancestral plumage of the widespread Terpsiphone genus. The genus appears to have colonized south‐west Asia, the Indian Ocean and Africa from eastern Asia. The phylogeny and divergence time estimates indicate multiple simultaneous colonizations of the western Old World by Terpsiphone. These results reinforce a hypothesis of range expansions of a Terpsiphone paradisi‐like ancestor into eastern Asia and the western Old World.     

Diversity of non-glandular trichomes in subtribe Lychnophorinae (Asteraceae: Vernonieae) and taxonomic implications

Vernonieae is one of the major tribes in Asteraceae (subfamily Cichorioideae) with ca. 1,100 species placed into 129 genera. Currently, 21 subtribes are recognized in Vernonieae and one of them is Lychnophorinae, almost entirely endemic to Brazil, containing 11 genera and ca. 100 species. About 42 % of Lychnophorinae genera are monophyletic, reflecting the poorly understood relationships among the members of the group. Trichomes are one of the most useful anatomical characters to be used in angiosperm taxonomy; they are diverse, exist in many taxa and are not difficult to study. This work intends to illustrate non-glandular leaf trichome diversity in Lychnophorinae and discuss this diversity in the light of the subtribe’s taxonomy. Sampled material included 67 species of 11 genera. Macerations and free hand sections were performed to be analyzed in the light microscope and photographed. A phenogram was generated using a matrix with 67 terminals (species) and 18 characters coded as binary. The subtribe Lychnophorinae displays a great diversity of non-glandular trichomes (5 types and 18 subtypes). The present study reveals the great diversity of non-glandular trichomes in Lychnophorinae. While trichome complement is of little use to distinguish genera, it appears to be a valuable characteristic at a lower taxonomic level to identify closely morphologically related species.     

Origins of the secondary plastids of Euglenophyta and Chlorarachniophyta as revealed by an analysis of the plastid‐targeting,nuclear‐encoded gene psbO1

Because the secondary plastids of the Euglenophyta and Chlorarachniophyta are very similar to green plant plastids in their pigment composition, it is generally considered that ancestral green algae were engulfed by other eukaryotic host cells to become the plastids of these two algal divisions. Recent molecular phylogenetic studies have attempted to resolve the phylogenetic positions of these plastids; however, almost all of the studies analyzed only plastid‐encoded genes. This limitation may affect the results of comparisons between genes from primary and secondary plastids, because genes in endosymbionts have a higher mutation rate than the genes of their host cells. Thus, the phylogeny of these secondary plastids must be elucidated using other molecular markers. Here, we compared the plastid‐targeting, nuclear‐encoded, oxygen‐evolving enhancer (psbO) genes from various green plants, the Euglenophyta and Chlorarachniophyta. A phylogenetic analysis based on the PsbO amino acid sequences indicated that the chlorarachniophyte plastids are positioned within the Chlorophyta (including Ulvophyceae, Chlorophyceae, and Prasinophyceae, but excluding Mesostigma). In contrast, plastids of the Euglenophyta and Mesostigma are positioned outside the Chlorophyta and Streptophyta. The relationship of these three phylogenetic groups was consistent with the grouping of the primary structures of the thylakoid‐targeting domain and its adjacent amino acids in the PsbO N‐terminal sequences. Furthermore, the serine‐X‐alanine (SXA) motif of PsbO was exactly the same in the Chlorarachniophyta and the prasinophycean Tetraselmis. Therefore, the chlorarachniophyte secondary plastids likely evolved from the ancestral Tetraselmis‐like alga within the Chlorophyta, whereas the Euglenophyte plastids may have originated from the unknown basal lineage of green plants.     

Underestimated biodiversity as a major explanation for the perceived rich secondary metabolite capacity of the cyanobacterial genus Lyngbya

Marine cyanobacteria are prolific producers of bioactive secondary metabolites responsible for harmful algal blooms as well as rich sources of promising biomedical lead compounds. The current study focused on obtaining a clearer understanding of the remarkable chemical richness of the cyanobacterial genus Lyngbya. Specimens of Lyngbya from various environmental habitats around Curaçao were analysed for their capacity to produce secondary metabolites by genetic screening of their biosynthetic pathways. The presence of biosynthetic pathways was compared with the production of corresponding metabolites by LC‐ESI‐MS² and MALDI‐TOF‐MS. The comparison of biosynthetic capacity and actual metabolite production revealed no evidence of genetic silencing in response to environmental conditions. On a cellular level, the metabolic origin of the detected metabolites was pinpointed to the cyanobacteria, rather than the sheath‐associated heterotrophic bacteria, by MALDI‐TOF‐MS and multiple displacement amplification of single cells. Finally, the traditional morphology‐based taxonomic identifications of these Lyngbya populations were combined with their phylogenetic relationships. As a result, polyphyly of morphologically similar cyanobacteria was identified as the major explanation for the perceived chemical richness of the genus Lyngbya, a result which further underscores the need to revise the taxonomy of this group of biomedically important cyanobacteria.     

Generation gland morphology in cordylid lizards: An evolutionary perspective

To elucidate the functional significance of the three distinct types of generation glands that have been identified among cordylid lizards, we mapped gland type to the terminal taxa in the most recent phylogenetic tree for the Cordylidae. We used the phylogenetic programme Mesquite and applied the principle of parsimony to infer character states for the ancestral nodes in the tree. For those species where information on gland type was not available from the literature, we conducted a histological investigation of generation gland morphology, using standard histological techniques. We included two species of the sister family Gerrhosauridae in the analysis to serve as outgroups. In both Gerrhosaurus typicus and G. flavigularis, scales immediately anterior to the femoral pores displayed glandular activity, but differed from generation glands of cordylids in the absence of mature glandular generations. Among the cordylids investigated, we identified a fourth type of generation gland in Pseudocordylus subviridis, P. spinosus, and in the two Hemicordylus species, one where the glands consistently comprise of two mature glandular generations. In H. capensis, both single‐ and two‐layer type glands are present. Our reconstruction of ancestral character states suggests a minimum of six transformations from one gland type to another during the evolutionary history of the family. The reconstruction furthermore suggests that the single‐layer type gland reappeared at least once (in Hemicordylus) in the Cordylinae after having been lost. The reconstruction also unequivocally shows that the pit‐like multiple‐layer type gland evolved directly from the single‐layer type and not from the protruding multiple‐layer type. The two‐layer type gland appears to be an intermediary condition between the multiple‐layer and single‐layer types. The evolutionary transformation of generation gland type appears to be linked to changes in lifestyle and associated changes in degree of territoriality and the need for chemical communication. J. Morphol. 275:456–464, 2014. © 2013 Wiley Periodicals, Inc.     

Revision and phylogenetic assessment of the rove beetle genus Pseudohesperus Hayashi,with broad reference to the subtribe Philonthina (Coleoptera: Staphylinidae: Staphylinini)

This paper studies the phylogeny of the rove beetle subtribe Philonthina, to test its hypothetical monophyly and to unravel the evolutionary relationships of the subtribe and its included genus‐level taxa, with emphasis on the genus Pseudohesperus and its close‐allied relatives. The phylogenetic analyses are based on 105 adult morphological characters and 66 terminal taxa, i.e., all six members of Pseudohesperus, 51 species to represent 29 other genera of the subtribe Philonthina, seven species to represent the other six subtribes of Staphylinini, one species of the tribes Arrowinini, and one of the Platyprosopini. According to the phylogenetic results obtained, the genus Erichsonius should move out from the hitherto‐defined subtribe Philonthina and thus the monophyly of this taxon is challenged. The phylogenetic tree suggests that the genera Hesperus and Belonuchus might not be monophyletic, but the monophyly of Pseudohesperus and the sister relationship between it and Bisnius are well supported. The species‐level phylogenetic relationships of the genus Pseudohesperus reveal a clear pattern of species diversification that can be correlated well with the species' zoogeographical patterns. The paper also revises the taxonomy of Pseudohesperus and describes five new species from China: Pseudohesperus luteus Li & Zhou sp. nov. , Pseudohesperus pedatiformis Li & Zhou sp. nov. , Pseudohesperus tripartitus Li & Zhou sp. nov. , Pseudohesperus sparsipunctatus Li & Zhou sp. nov. , and Bisnius lubricus Li & Zhou sp. nov. An identification key to the species of Pseudohesperus is provided and their geographical distributions are mapped. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 679–722.     

PHYLOGENETIC CONSTRAINTS IN KEY FUNCTIONAL TRAITS BEHIND SPECIES’ CLIMATE NICHES: PATTERNS OF DESICCATION AND COLD RESISTANCE ACROSS 95 DROSOPHILA SPECIES

Species distributions are often constrained by climatic tolerances that are ultimately determined by evolutionary history and/or adaptive capacity, but these factors have rarely been partitioned. Here, we experimentally determined two key climatic niche traits (desiccation and cold resistance) for 92–95 Drosophila species and assessed their importance for geographic distributions, while controlling for acclimation, phylogeny, and spatial autocorrelation. Employing an array of phylogenetic analyses, we documented moderate‐to‐strong phylogenetic signal in both desiccation and cold resistance. Desiccation and cold resistance were clearly linked to species distributions because significant associations between traits and climatic variables persisted even after controlling for phylogeny. We used different methods to untangle whether phylogenetic signal reflected phylogenetically related species adapted to similar environments or alternatively phylogenetic inertia. For desiccation resistance, weak phylogenetic inertia was detected; ancestral trait reconstruction, however, revealed a deep divergence that could be traced back to the genus level. Despite drosophilids’ high evolutionary potential related to short generation times and high population sizes, cold resistance was found to have a moderate‐to‐high level of phylogenetic inertia, suggesting that evolutionary responses are likely to be slow. Together these findings suggest species distributions are governed by evolutionarily conservative climate responses, with limited scope for rapid adaptive responses to future climate change.     

EXAMINING TWO STANDARD ASSUMPTIONS OF ANCESTRAL RECONSTRUCTIONS: REPEATED LOSS OF DICHROMATISM IN DABBLING DUCKS (ANATINI)

Although phylogenetic reconstruction of ancestral character states is becoming an increasingly common technique for studying evolution, few researchers have assessed the reliability of these reconstructions. Here I test for congruence between a phylogenetic reconstruction and a widely accepted scenario based on independent lines of evidence. I used Livezey's (1991) phylogeny to reconstruct ancestral states of plumage dichromatism in dabbling ducks (Anatini). Character state mapping reconstructs monochromatic ancestors for the genus Anas as well as most of its main clades. This reconstruction differs strongly from the widely accepted scenario of speciation and plumage evolution in the group (e.g., Delacour and Mayr 1945; Sibley 1957). This incongruence may occur because two standard assumptions of character state reconstruction are probably not met in this case. Violating either of these two assumptions would be a source of error sufficient to create misleading reconstructions. The first assumption that probably does not apply to ducks is that terminal taxa, in this case species, are monophyletic. Many of the widespread dichromatic species of ducks may be paraphyletic and ancestral to isolated monochromatic species. Three lines of evidence support this scenario: population-level phylogenies, biogeography, and vestigial plumage patterns. The second assumption that probably does not apply to duck plumage color is that gains and losses of character states are equally likely. Four lines of evidence suggest that dichromatic plumage might be lost more easily than gained: weak female preferences for bright male plumage, biases toward the loss of sexually dichromatic characters, biases toward the loss of complex characters, and repeated loss of dichromatism in other groups of birds. These seven lines of evidence support the accepted scenario that widespread dichromatic species repeatedly budded off isolated monochromatic species. Drift and genetic biases probably caused the easy loss of dichromatism in ducks and other birds during peripatric speciation. In order to recover the accepted scenario using Livezey's tree, losses of dichromatism must be five times more likely than gains. The results of this study caution against the uncritical use of unordered parsimony as the sole criterion for inferring ancestral states. Detailed population-level sampling is needed and altered transformation weighting may be warranted in ducks and in many other groups and character types with similar attributes.     

Aristolochiaceae‐ and Asteraceae‐feeding by larvae of Papilio xuthus L. (Lepidoptera: Papilionidae) in Japan: A review

Our recent observations of Aristolochiaceae‐ and Asteraceae‐feeding by larvae of Papilio xuthus L. (Lepidoptera: Papilionidae), which is generally a typical Rutaceae‐feeding swallowtail, inspired us to survey published works describing its host range and aspects of its chemical ecology. Papilio xuthus larvae have been observed feeding on a total of 22 plant species other than members of Rutaceae, including those of Asarum (Aristolochiaceae) and Cosmos (Asteraceae). Most observation records and our current study indicated that Aristolochiaceae‐feeding by P. xuthus larvae was not due to oviposition error, but to larval movement to Asarum from adjacent rutaceous hosts after they had become unsustaining. Many larvae developed on Asarum to further stadia but we confirmed that some did not, indicating that Asarum was unsuitable for some individuals. According to previous and current observations, P. xuthus females oviposit directly on Cosmos and their larvae can develop to adults although, again, their performance on these plants is not always favorable. Host choice by swallowtail butterflies is determined both at the egg‐laying and larval‐feeding stages. Although adult P. xuthus use a mixture of unique secondary metabolites as their host‐location cue, larvae use primary nutrients as their major phagostimulants. Larval feeding on Asarum could suggest a reversion triggered by vestigial chemosensitivity to ancestral olfactory and/or gustatory cues, because several major clades of Papilionidae feed on Aristolochiaceae. Further studies on the phytochemical/chemosensory bases for these associations are needed if we are to understand the evolutionary pathway of host selection in P. xuthus, as indicated by these relatively unusual host‐seeking behaviors.     

Molecular evolution and diversification of the moss family Daltoniaceae (Hookeriales,Bryophyta) with emphasis on the unravelling of the phylogeny of Distichophyllum and its allies

Phylogenetic relationships in Daltoniaceae (～200 species in 14 genera) are inferred from nucleotide sequences from five genes, representing all genomic compartments, using parsimony, likelihood and Bayesian methods. Alternative classifications for Daltoniaceae have favoured traits from either sporophytes or gametophytes; phylogenetic transitions in gametophytic leaf limbidia and sporophytic exostome ornamentation were evaluated using ancestral state reconstruction to assess the levels of conflict between these generations. Elimbate leaves and the cross‐striate exostome are reconstructed as plesiomorphic states. Limbate leaves and papillose exostomes evolved at least two and six times, respectively, without reversals. The evolution of leaf limbidia is relatively conserved, but exostome ornamentation is highly homoplasious, indicating that superficial similarity in peristomes gives unreliable approximations of phylogenetic relatedness. Our phylogenetic analyses show that Achrophyllum and Calyptrochaeta are reciprocally monophyletic. Within core Daltoniaceae, relationships among taxa with elimbate leaves are generally well understood. However, taxa with limbate leaves form a monophyletic group, but resolved subclades correspond to biogeographical entities, rather than to traditional concepts of genera. Daltonia (～21 species), Distichophyllum (～100 species) and Leskeodon (～20 species) are polyphyletic. Seven nomenclatural changes are proposed here. As the current taxonomy of Daltoniaceae lacks phylogenetic consistency, critical generic revisions are needed. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ?? , ??–??.     

Chromosome studies in Orchidaceae: karyotype divergence in Neotropical genera in subtribe Maxillariinae

Here, we study karyotype divergence in the closely related genera Brasiliorchis, Christensonella and Trigonidium belonging to subtribe Maxillariinae of subfamily Epidendroideae (Orchidaceae). We compare karyotypes in 15 species by (1) measuring 1C genome sizes, (2) mapping the distribution of 4′,6‐diamidino‐2‐phenylindole and chromomycin A3 chromosome bands and (3) localizing 5S and 45S nuclear ribosomal DNA (rDNA) sequences using fluorescent in situ hybridization. Recently, phylogenetic studies have been conducted to resolve species and genera relationships in subtribe Maxillariinae. We used these phylogenetic trees to map the cytogenetic characters in an evolutionary framework. This has enabled a better understanding of the patterns of genomic divergence in the group. Genome sizes range from 1C = 1.85 to 4.1 pg. The largest, B. schunkeana, shows evidence of genome upsizing, probably through the acquisition of tandem repeats that now form large 4′,6‐diamidino‐2‐phenylindole‐positive blocks of heterochromatin. Our cytogenetic data are consistent with a base chromosome number of 2n = 40, although Christensonella is characterized by a dysploid reduction in chromosome number to 2n = 36. The number of 5S and 45S rDNA sites is variable between species, consistent with high rates of karyotype divergence. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170 , 29–39.     

Chemistry and biological activity of azoprenylated secondary metabolites

N-Prenyl secondary metabolites (isopentenylazo-, geranylazo-, farnesylazo- and their biosynthetic derivatives) represent a family of extremely rare natural products. Only in recent years have these alkaloids been recognized as interesting and valuable biologically active secondary metabolites. To date about 35 alkaloids have been isolated from plants mainly belonging to the Rutaceae family, and from fungi, bacteria, and/or obtained by chemical synthesis. These metabolites comprise anthranilic acid derivatives, diazepinones, and indole, and xanthine alkaloids. Many of the isolated prenylazo secondary metabolites and their semisynthetic derivatives are shown to exert valuable in vitro and in vivo anti-cancer, anti-inflammatory, anti-bacterial, anti-viral, and anti-fungal effects. The aim of this comprehensive review is to examine the different types of prenylazo natural products from a chemical, phytochemical and biological perspective.