Inflorescence structure and affinities of Laurophyllus (Anacardiaceae)

WANNAN, B. S. & QUINN, C. J., 1992. Inflorescence structure and affinities of Laurophyllus (Anacardiaceae). The inflorescence structure, pollen and floral anatomy are investigated in Laurophyllus . The inflorescence is a panicle sensu Briggs & Johnson, but with marked differences between the male and female. Sistergroup comparison with the Burseraceae indicates that the plesiomorphic inflorescence in the Anacardiaceae is a thyrsoid, the apomorph being the panicle. Laurophyllus has Rhus -type pollen and therefore has no close affinity with Dobinea or Campylopeialum . Floral anatomy reveals that Laurophyllus is unicarpellary with a dorsally attached style and an apically attached ovule. These characters suggest that rather than being related to Anacardium or Mangifera , it has some affinity with Blepharocarya or perhaps with one of the poorly known African or Madagascan genera.     

The complete plastid genome of Cotinus coggygria and phylogenetic analysis of the Anacardiaceae

Cotinus coggygria Scop. (Anacardiaceae) is an important ornamental tree with beautiful characteristics that is grown in China. In this study, the complete plastid genome of C. coggygria was sequenced and assembled. This genome was 158,843 bp in size and presented a typical tetrad structure, consisting of a large single-copy region (87,121 bp), a pair of inverted repeat regions (26,829 bp), and a small single-copy region (18,064 bp). A total of 134 genes were annotated, including 88 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. We observed a deletion that caused the loss of the rpl32 gene, and a small expansion of IR regions resulted in the trnH gene accessing IR regions; two copies were obtained. Phylogenetic analysis showed that C. coggygria was most closely related to Pistacia, with 100% bootstrap support within Anacardiaceae. In this study, we report the plastid genome of Cotinus species for the first time, which provides insight into the evolution of the plastid genome in Anacardiaceae and promotes the understanding of Cotinus plants.     

The pretarsus in Chalcidoidea (Hymenoptera Parasitica): functional morphology and possible phylogenetic implications

The structure of the pretarsus of chalcid wasps (Hymenoptera: Chalcidoidea) was examined with light and scanning electron microscopy. The pretarsus of these wasps is characterized by a distal elastic widening of the planta that spreads over the arcus, by a pair of folding plates at the dorsal side of the arolium (the dorsal plates), and by the absence of auxiliary sclerites. The surface of the fully spread arolium of chalcids has a spongiform structure. The arcus of chalcids is an apodeme of the planta. The peculiarities of the inverting/everting biomechanics of the pretarsus of chalcids involve: 1) interactions between the elastic part of the planta, the dorsal plates and the manubrium, and 2) the functioning of the elastic part of the planta and the arcus together as a single unit. A single apical seta situated distally from the campaniform sensillae and proximal row of setae on the manubrium are regarded as putative synapomorphies of Chalcidoidea. A manubrium with a distinct proximal row of three setae characterizes almost all Eulophidae, Aphelinidae and Signiphoridae (‘eulophid lineage’) and Tetracampidae, whereas a row of two setae characterizes Mymaridae, Rotoitidae and Trichogrammatidae. Other studied families (Pteromalidae, Eurytomidae, Torymidae, Ormyridae, Eupelmidae, Encyrtidae, Perilampidae), which represent a ‘pteromalid lineage’, are characterized mostly by five setae in a proximal row, which could represent a synapomorphy for these groups, or a symplesiomorphy in Chalcidoidea, depending on rooting. However, the characters may be correlated with differences in body size that characterize the different lineages rather than being phylogenetically important. Other characters that may be phylogenetically informative are: 1) shape of the manubrium (spindle‐like in Mymaridae, Rotoitidae, Trichogrammatidae and the ‘eulophid lineage’, but mostly bottle‐like in representatives of the ‘pteromalid lineage’), and 2) pubescence of the proximal part of the planta (sparse, thick setae in Rotoitidae, Trichogrammatidae and the ‘eulophid lineage’, but dense, slender setae in representatives of the ‘pteromalid lineage’).     

Germination and seedling morphology of four South American Smilax (Smilacaceae)

Species of Smilax, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30 degrees C and 20-30 degrees C) and light (presence/ absence), and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30 degrees C in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%), independently of treatment. However, S. polyantha had low germination rates (19-24%). After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovate-elliptic, coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics.     

Functional morphology and wasp pollination of two South American asclepiads (Asclepiadoideae-Apocynaceae)

Background and Aims

The extreme complexity of asclepiad flowers (Asclepiadoideae–Apocynaceae) has generated particular interest in the pollination biology of this group of plants especially in the mechanisms involved in the pollination processes. This study compares two South American species, Morrenia odorata and Morrenia brachystephana, with respect to morphology and anatomy of flower structures, dynamic aspects of the pollination mechanism, diversity of visitors and effectiveness of pollinators.

Methods

Floral structure was studied with fresh and fixed flowers following classical techniques. The pollination mechanism was studied by visiting fresh flowers in the laboratory with artificial pollinator body parts created with an eyelash. Morphometric and nectar measurements were also taken. Pollen transfer efficiency in the flowers was calculated by recording the frequency of removed and inserted pollinia. Visitor activity was recorded in the field, and floral visitors were captured for subsequent analysis of pollen loads. Finally, pollinator effectiveness was calculated with an index.

Key Results

The detailed structure of the flowers revealed a complex system of guide rails and chambers precisely arranged in order to achieve effective pollinaria transport. Morrenia odorata is functionally specialized for wasp pollination, and M. brachystephana for wasp and bee pollination. Pollinators transport chains of pollinaria adhered to their mouthparts.

Conclusions

Morrenia odorata and M. brachystephana present differences in the morphology and size of their corona, gynostegium and pollinaria, which explain the differences in details of the functioning of the general pollination mechanism. Pollination is performed by different groups of highly effective pollinators. Morrenia species are specialized for pollination mainly by several species of wasps, a specialized pollination which has been poorly studied. In particular, pompilid wasps are reported as important pollinators in other regions outside South Africa. A putative new function of nectar in asclepiads is presented, as it would be contributing to the pollination mechanism.     

Inflorescence development of Whytockia (Epithemateae, Gesneriaceae) and phylogenetic implications within Gesneriaceae

 The inflorescence development in Whytockia has been studied in order to explore the developmental basis for inflorescence architecture. The developmental pattern of the pair-flowered cyme in Whytockia basically conforms to that of most members in Gesneriaceae. However, the additional flower beside the terminal one in Whytockia is not equivalent to the frontal flower as in other Gesneriaceae because the former is located in the front-lateral position while the latter is in the front-median position. Also, the zigzag monochasial branching system in Whytockia represents the consecutive front-lateral branches rather than the lateral branches as in other Gesneriaceae. The inflorescence in Whytockia is flowering in a basipetal sequence, and its seemingly acropetal flowering sequence is due to the vigorous development of the consecutive front-lateral branches. In addition, the inflorescence of Whytockia does not represent the basic unit of the inflorescence in Epithemateae, and it is derived as compared to that of Rhynchoglossum. The development relationships of the inflorescence between Whytockia and its allies in Epithemateae are discussed on the basis of developmental and comparative evidence. Received February 15, 2002; accepted September 17, 2002 Published online: December 11, 2002     

Diversification of South American spiny rats (Echimyidae): a multigene phylogenetic approach

Fabre, P.‐H., Galewski, T., Tilak, M.‐k. & Douzery, E.J.P. (2012) Diversification of South American spiny rats (Echimyidae): a multigene phylogenetic approach. —Zoologica Scripta, 00, 000–000. We investigated the phylogenetic relationships of 14 Echimyidae (spiny rats), one Myocastoridae (nutrias) and one Capromyidae (hutias) genera based on three newly sequenced nuclear genes (APOB, GHR and RBP3) and five previously published markers (the nuclear RAG1 and vWF, and the mitochondrial cytochrome b, 12S rRNA and 16S rRNA). We recovered a well‐supported phylogeny within the Echimyidae, although the evolutionary relationships among arboreal echimyid taxa remain unresolved. Molecular divergence times estimated using a Bayesian relaxed molecular clock suggest a Middle Miocene origin for most of the extant echimyid genera. Echimyidae seems to constitute an example of evolutionary radiation with high species diversity, yet they exhibit only narrow skull morphological changes, and the arboreal and terrestrial taxa are shown to retain numerous plesiomorphic features. The most recent common ancestor of spiny rats is inferred to be a ground‐dwelling taxon that has subsequently diverged into fossorial, semiaquatic and arboreal habitats. The arboreal clade polytomy and ancestral character estimations suggest that the colonization of the arboreal niche constituted the keystone event of the echimyid radiation. However, biogeographical patterns suggest a strong influence of allopatric speciation in addition to ecology‐driven diversification among South American spiny rats.     

Inflorescence and floral morphology of Haptanthus hazlettii (Buxaceae,Buxales)

The enigmatic Central American tree Haptanthus hazlettii has recently been placed in Buxaceae (Buxales) by molecular evidence. However, Haptanthus appears morphologically to be fundamentally different from other Buxales in having pluriovular carpels with parietal placentation and reduced male reproductive units of an obscure morphological nature. The latter have been interpreted to be pairs of unistaminate flowers, or single flowers, either bearing two stamens or a pair of phyllomes with adnate introrse anthers. We (re‐)investigated the structure of the inflorescences and flowers of Haptanthus in order to clarify their homologies with reproductive structures of Buxales. We found that, despite some distinctive traits of flower morphology, Haptanthus shares many floral characters, including the opposite and pairwise arrangement of floral organs and the fusion between perianth members and stamens, with some Buxales and other early‐branching eudicots. The plicate and pluriovular gynoecium of Haptanthus may be the result of a drastic elongation of the symplicate zone, accompanied by an increase in ovule number, and is thus a derived trait in Buxales. The anther‐bearing structures are phyllomes with adnate anthers rather than stamens or unistaminate flowers. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 190–200.     

Systematic revision and phylogenetic analysis of the South American genus Chlorus (Orthoptera, Acridoidea, Melanoplinae)

The South American grasshopper genus Chlorus (Melanoplinae, Dichroplini) from Bolivia, southern Brazil and Paraguay is revised. Cladistic analysis of morphological characters indicates that Chlorus constitutes a monophyletic group whose generic relationships remain unsolved. If the external morphology is considered, Chlorus showed to be related to Dichromatos , while characters from the male genitalia support the relationship between Chlorus and Eurotettix. Seven species are recognised for Chlorus with three of them described as new: Chlorus spatulus, Ch. chiquitensis and Ch. attenuatus . Keys to the species of the genus and a review of the morphological characters defining the taxa are provided.     

On the morphology of spermatozoa in some African murines (Rodentia, Muridae): the taxonomic and phylogenetic aspects

A comparative analysis of sperm-head morphology and measurements in 17 species from nine genera of African Murinae: Rattus rattus, Mastomys coucha, M. huberti, M. erythroleucus, Mastomys sp. 2, Praomys albipes, P. fumatus, Mus mahomet, Arvicanthis somalicus, A. abyssinicus, A. dembeensis, Arvicanthis sp., Lemniscomys macculus, Pelomys harringtoni, Acomys cahirinus, Acomys sp., Uranomys ruddi, was carried out. Spermatozoa of all examined species are of the same basic type. They consist of an asymmetrical head, falciform or scythelike in shape, and a tail attached to the ventrocaudal surface of the head. There are great interspecific differences in sperm morphology and size. The significance of this variation for estimation of taxonomic aspects and phylogenetic relationships among the species, as well as between them and other groups, is discussed. The sperm morphology supports a close evolutionary relationship among the genera Lemniscomys and Arvicanthis. It also indicates that Pelomys is distinctive. The relationships between Acomys and Uranomys are discussed.     

Chromosome number of some South American species ofNothofagus (Fagaceae)

The observed chromosome numbers for four deciduous species of South AmericanNothofagus (Sect.Nothofagus) are 2n=26. This chromosome count is the first report on the South American species of the genus, and is the same number as reported for the New Zealand counterparts of the evergreen sectionCalusparassus. Furthermore, a significant difference between the karyotypes of two subsections within the Sect.Nothofagus has been recognized.     

The comparative osteology and phylogenetic relationships of African and South American lungfishes (Sarcopterygii: Dipnoi)

Lepidosirenidae is a clade of freshwater lungfishes that include the extant South American Lepidosiren paradoxa Fitzinger, 1837 and African species of the genus Protopterus. These genera have been geographically separated since the break‐up of Gondwana in the Early Cretaceous, but they display similar biology and morphology. Species were distinguished by a combination of features such as head‐to‐body ratios, the number of pairs of ribs, and the presence of external gills, but no discrete skeletal characters were identified, and no comparative studies including all extant species have been published. I used computed tomography (CT), X‐ray photography, and specimens from museum collections to describe the skeletal morphology of all species of lepidosirenid in a comparative context. I digitally disarticulated the bones in each specimen to compile a comparative atlas of the cranial and pectoral elements of all extant lungfishes, which has the potential to increase the correct identifications of specimens in museum collections. The morphology of the frontoparietal, parasphenoid, supraorbital, and suboperculum differ between species. I used those characters, along with molecular sequence data from the ribosomal RNA gene 16S, to run combined morphological and molecular phylogenetic analyses. Lepidosirenidae is monophyletic in all analyses, but the interrelationships of the species of Protopterus vary with the different sources of character data. © 2015 The Linnean Society of London     

Functional morphology and phylogenetic testing within the framework of symecomorphosis

On the basis of the contrasting evolutionary patterns of the Teleostei and the "Chondrostei" the merit of phylogenetic testing is summarized as a non-arbitrary method for assessing the possible role of various designs in producing differential morphological diversity in different lineages. Arguments are presented for the recognition of a genealogical (reproductive, informational) and an ecological hierarchy. Various levels are proposed within hierarchies, because there are processes intrinsic to each level that are not reducible to those of lower levels or subsumed by higher levels. Mutual influences exist between successive levels within a hierarchy and possible interhierarchical mutual influences are hypothesized between organisms, demes, and avatars, and from the germ line to functional units. The term symecomorphosis is proposed to denote the balanced symmetry of the co-existing and mutually interdependent ecological and genealogical hierarchies. Symecomorphosis predicts that a disturbance in environmental systems can destroy this balance with profound effects on the genealogical hierarchy. Using the evolutionary differentiation of four lineages of air breathing teleosts as an example, it is demonstrated how the principle of symecomorphosis can be included in tests establishing a causal relationship between design and differential diversity among lineages.     

Age-related changes in ovarian morphology of the South American tamarin Saguinus fuscicollis (Callitrichidae)

The aim of this histological study was to investigate the postnatal ontogeny of the ovaries in Saguinus fuscicollis to provide a detailed knowledge of the ovarian morphology for further endocrinological studies. Gonads from 43 animals between one day and 18 years of age were investigated. Based on the available material the ovarian development is characterized by seven distinct stages. 1. Neonatal stage : Folliculogenesis is still in progress. The ovarian medulla is filled with an intraovarian rete system, which forms open connections between the rete tubules and the cords containing oocytes. 2. Infantile stage : One month after birth the ovarian cortex is mainly composed of primordial follicles and a few primary follicles at the corticomedullary border, which are separated from each other by connective tissue. At two months, folliculogenesis is nearly completed. The first secondary follicles are present. 3. Juvenile stage : In six-month-old females weighing 184±9.5 g, folliculogenesis has reached the stage of secondary follicles with up to six layers of granulosa cells. In females of the same age weighing 251.5±37 g, antral follicles attain a maximum diameter of 925 μm m. 4. Pubertal stage : At the age of 8–10 months, corpora lutea accessoria (CLA) begin to form from atretic antral follicles. 5. Adult stage : The ovaries of all females older than 1.2 years are filled with large patches of interstitial gland tissue (IGT). In breeding females up to 58.4%of the antral follicles are intact. In non-breeding daughters living in the family group only 1.8%are intact, the rest are in various stages of atresia and form CLA. 6. Climacterial stage : With increasing age (8–13 years), the number of intact follicles decreases dramatically and IGT fills nearly the whole ovary. 7. Senile stage : In females older than 14 years, nearly all remaining follicles show signs of atresia.     

Historical and phylogenetic constraints on the incidence of entire leaf margins: insights from a new South American model

Aim The relationship between the proportion of species with an entire leaf margin (pE) and mean annual temperature (MAT) is one of the most powerful tools for estimating palaeotemperatures. However, phylogenetic and phytogeographic constraints on this relationship have remained unexplored. Here we investigate the pE–MAT relationship for modern floristic assemblages from southern South American forests, assess its conformity to other models and test for the existence of historical constraints on pE–MAT models. Location South America. Methods We used samples from 30 sites located in Chile between 32° and 44° S to test for a pE–MAT relationship and compared it with four regional models. We assessed the reliability of these models for predicting MAT from instrumental records in eight modern temperate‐forest localities in Chile. Additionally, palaeotemperatures for Cenozoic fossil floras were estimated. To assess historical constraints in pE, we measured the phylogenetic signal in leaf margin type and the association between leaf margin and phytogeographic affiliation, defined by the distribution of genera. Results We found a significant pE–MAT relationship for Chilean forest species that differed from Australia and Northern Hemisphere models, but not from tropical South America (TSA). Temperatures for southern South American localities predicted from the new regional model – combining Chilean and TSA datasets – were more accurate than those from previous models. We also showed that leaf margin type has a strong phylogenetic signal, which was further confirmed by the highly significant effect of phytogeographic element on leaf margin type. Main conclusions Differences between the Chilean and other regional models are explained by historical legacy, as Chilean leaf margin types are strongly affected by phylogenetic closeness and phytogeographic elements. We highlight that leaf margin analyses should be conducted within the context of a flora with a shared history. Thus, we propose a new model for South America to estimate palaeotemperatures for regional fossil floras.     

Intestinal helminths in lowland South American Indians: some evolutionary interpretations

Data on intestinal parasite infections for South American Indians in prehistoric times as revealed by coprolite analysis are being used to support transoceanic migration routes from the Old World to the New World. These same findings on modern semi-isolated aborigines, considered persisting prehistoric patterns, are also of great importance as indicators of pre-Columbian peopling of South America. This is the case for the Lengua Indians from Paraguay, studied in the 1920s, and the Yanomami and the Salum? from Brazil, studied in the 1980s. The intestinal parasitic profile of these groups can be empirically associated with culture change, but no clear correlations with the population biology of their hosts can be made at present because of scarcity of data.