Morphological and acoustic characters of Cicadatra?platyptera Fieber, 1876

Acoustic and morphological characters are very important to distinguish species of Cicadidae. In this study, the morphological and acoustic characters of Cicadatra platyptera Fieber, 1876 (Hemiptera, Cicadidae) collected from Turkey were analysed. The external morphological structures of two species were drawn and photographs of some specimens were taken. We evaluated taxonomically important morphological characters such as body shape, colors, patterns, structure, and genital structure. We evaluated measurements of external morphological structures and acoustics characters of Cicadatra platyptera from Turkey, partly with statistical analyses. Morphological characters were compared and differentiated from the closely related species, Cicadatra atra. The distribution in Turkey including previous records and the material examined were shown on a map, and the distribution in Palearctic Region was given.     

Morphology of Females and Cysts of Globodera tabacum tabacum,G. t. virginiae,and G. t. solanacearum (Nemata: Heteroderinae)

Detailed morphological comparisons with light and scanning electron microscopy were made of white females and cysts of several isolates of Globodera tabacum sspp. tabacum (GTT), virginiae (GTV), and solanacearum (GTS). Observations focused on body shape, anterior region including head shape, lip pattern, stylet morphology, and the terminal area in females; and body shape and terminal area of cysts. The most useful characters to separate the three subspecies were forms of the female body, cyst, stylet knobs, tail region, perineal tubercles, anal-fenestral ridge patterns, and the distinctiveness of the anus. GTT is characterized by having round females and cysts, sharply back sloped stylet knobs, clumped perineal tubercles in the vulval region, tight parallel ridges in the cyst anal-fenestral region, and a uniformly conoid tail region. GTV is characterized by its ovoid to ellipsoid female and cyst shape, the "Dutch shoe" shape of the dorsal stylet knob, the more dispersed perineal tubercles, a maze-like pattern of ridges in the anal-fenestral region, and an indistinct anus. GTS is characterized by its ovoid to ellipsoid female and cyst shape, moderately backward sloped stylet knobs, more widely separated ridges, a distinct anus, and a usually crescent shaped tail region. Much variability in shape and patterns is visible among all the isolates of the different subspecies. Tubercles in the neck, as well as bullae, are reported, and their taxonomic value is discussed.     

Interspecific gene flow in a multispecies oak hybrid zone in the Sierra Tarahumara of Mexico

Background and Aims

Interspecific gene flow can occur in many combinations among species within the genus Quercus, but simultaneous hybridization among more than two species has been rarely analysed. The present study addresses the genetic structure and morphological variation in a triple hybrid zone formed by Q. hypoleucoides, Q. scytophylla and Q. sideroxyla in north-western Mexico.

Methods

A total of 247 trees from ten reference and 13 presumed intermediate populations were characterized using leaf shape variation and geometric morphometrics, and seven nuclear microsatellites as genetic markers. Discriminant function analysis was performed for leaf shape variation, and estimates of genetic diversity and structure, and individual Bayesian genetic assignments were obtained.

Key Results

Reference populations formed three completely distinct groups according to discriminant function analysis based on the morphological data, and showed low, but significant, genetic differentiation. Populations from the zone of contact contained individuals morphologically intermediate between pairs of species in different combinations, or even among the three species. The Bayesian admixture analysis found that three main genetic clusters best fitted the data, with good correspondence of reference populations of each species to one of the genetic clusters, but various degrees of admixture evidenced in populations from the contact area.

Conclusions

The three oak species have formed a complex hybrid zone that is geographically structured as a mosaic, and comprising a wide range of genotypes, including hybrids between different species pairs, backcrosses and probable triple hybrids.     

A comparative analysis of leaf shape of wheat, barley and maize using an empirical shape model

Background and Aims

The phenotypes of grasses show differences depending on growth conditions and ontogenetic stage. Understanding these responses and finding suitable mathematical formalizations are an essential part of the development of plant and crop models. Usually, a marked change in architecture between juvenile and adult plants is observed, where dimension and shape of leaves are likely to change. In this paper, the plasticity of leaf shape is analysed according to growth conditions and ontogeny.

Methods

Leaf shape of Triticum aestivum, Hordeum vulgare and Zea mays cultivars grown under varying conditions was measured using digital image processing. An empirical leaf shape model was fitted to measured shape data of single leaves. Obtained values of model parameters were used to analyse the patterns in leaf shape.

Key Results

The model was able to delineate leaf shape of all studied species. The model error was small. Differences in leaf shape between juvenile and adult leaves in T. aestivum and H. vulgare were observed. Varying growth conditions impacted leaf dimensions but did not impact leaf shape of the respective species.

Conclusions

Leaf shape of the studied T. aestivum and H. vulgare cultivars was remarkably stable for a comparable ontogenetic stage (leaf rank), but differed between stages. Along with other aspects of grass architecture, leaf shape changed during the transition from juvenile to adult growth phase. Model-based analysis of leaf shape is a method to investigate these differences. Presented results can be integrated into architectural models of plant development to delineate leaf shape for different species, cultivars and environmental conditions.     

Holoparasitic Rafflesiaceae possess the most reduced endophytes and yet give rise to the world's largest flowers

Background and Aims

Species in the holoparasitic plant family Rafflesiaceae exhibit one of the most highly modified vegetative bodies in flowering plants. Apart from the flower shoot and associated bracts, the parasite is a mycelium-like endophyte living inside their grapevine hosts. This study provides a comprehensive treatment of the endophytic vegetative body for all three genera of Rafflesiaceae (Rafflesia, Rhizanthes and Sapria), and reports on the cytology and development of the endophyte, including its structural connection to the host, shedding light on the poorly understood nature of this symbiosis.

Methods

Serial sectioning and staining with non-specific dyes, periodic–Schiff''s reagent and aniline blue were employed in order to characterize the structure of the endophyte across a phylogenetically diverse sampling.

Key Results

A previously identified difference in the nuclear size between Rafflesiaceae endophytes and their hosts was used to investigate the morphology and development of the endophytic body. The endophytes generally comprise uniseriate filaments oriented radially within the host root. The emergence of the parasite from the host during floral development is arrested in some cases by an apparent host response, but otherwise vegetative growth does not appear to elicit suppression by the host.

Conclusions

Rafflesiaceae produce greatly reduced and modified vegetative bodies even when compared with the other holoparasitic angiosperms once grouped with Rafflesiaceae, which possess some vegetative differentiation. Based on previous studies of seeds together with these findings, it is concluded that the endophyte probably develops directly from a proembryo, and not from an embryo proper. Similarly, the flowering shoot arises directly from the undifferentiated endophyte. These filaments produce a protocorm in which a shoot apex originates endogenously by formation of a secondary morphological surface. This degree of modification to the vegetative body is exceptional within angiosperms and warrants additional investigation. Furthermore, the study highlights a mechanical isolation mechanism by which the host may defend itself from the parasite.     

First Report of Korean Cyst Nematode,Heterodera koreana,Parasitic on Bamboo,Phyllostachys nigra,from Iran

Bamboo is grown sporadically in the north of Iran and is confined to very limited areas. The history of growing bamboo was to some extent simultaneous with the entrance, commencement, and growth of the tea industry in the north about a century ago. The bamboo was used for making baskets to transfer the harvested tea foliage from farm to the factory and other linked functions. A main area allocated for bamboo growing is located in Lahidjan Agricultural Research Station (LARS) in the north of Iran, where several species of bamboo were cultivated in an area of 5 ha. The species include five species of Phyllostachys (viz., P. aurea, P. bambusoides, P. decora, P. nigra, P. vivax) and one species of Arundinaria gigantean, Pleioblastus fortune, and Semiarundinaria fastuosa; however, only P. aurea and P. nigra have been precisely identified. A survey on plant parasitic nematodes associated with bamboo mainly on P. nigra in LARS revealed second-stage juveniles of cyst forming nematode in soil samples. Further analysis of root and soil samples led to recovery of a cyst nematode belonging to the genus Heterodera and the Afenestrata group. Cysts, vulval cone, and second-stage juveniles were studied for morphological and morphometric features. The classical identification was followed by amplification of the ribosomal RNA-ITS region and the D2-D3 expansion segments of 28S large-subunit rRNA gene; the amplified fragments were sequenced, edited, and compared with those of the corresponding published gene sequences. New D2-D3 and rRNA-ITS gene sequences were deposited in the GenBank database under the accession numbers {"type":"entrez-nucleotide","attrs":{"text":"KR818910","term_id":"924272655","term_text":"KR818910"}}KR818910 and {"type":"entrez-nucleotide","attrs":{"text":"KR818911","term_id":"924272662","term_text":"KR818911"}}KR818911, respectively. Based on the morphological and molecular data, the species of the cyst-forming nematode was identified as H. koreana (Vovlas et al., 1992; Mundo-Ocampo et al., 2008). The body contour of cysts was mainly subspherical, vey often with irregular shape (Fig. 1A), yellowish to light brown, thin cuticle with fine zigzag pattern, without fenestration, lacking bulla, and underbridge. Vulval lips protruded, cuticular pattern of vulval cone with a tuberculate area (Fig. 2B), and vagina embedded into vulval lips. The second-stage juveniles cylindrical and slender, hemispherical cephalic framework, with three lines in lateral field, well-developed rounded stylet knobs, tail conoid tapring to fine rounded terminus, phasmids posterior to anus. The cyst measurements were (n = 21) length 502 ± 70 (420 to 640) µm; width = 408 ± 60 (320 to 520) µm; length/width = 1.23 ± 0.09 (1.07 to 1.5) µm. The morphometric characters of vulval cone were measured (n = 7): fenestral length = 62.4 ± 6.5 (51 to 71) µm; fenestral width = 50.7 ± 3.2 (45 to 54) µm; vulval slit = 51.9 ± 4.3 (46 to 59) µm; distance from vulva to anus = 51.3 ± 4.4 (43 to 56) µm. Second-stage juveniles showed the following morphometric characters (n = 14): L = 455 ± 11.3 (437 to 472) µm; a = 29.9 ± 0.9 (28.3 to 31.5); b΄ = 2.7 ± 0.4 (2.2 to 3.5); c = 7.4 ± 0.9 (6 to 8.9); ć = 6.1 ± 0.4 (5.1 to 6.7); lip region height = 3 µm; lip region width = 7.5 ± 0.5 (7 to 8) µm; stylet length = 18.1 ± 0.5 (17 to 19) µm; anterior end to median bulb = 72.2 ± 1.7 (70 to 75) µm; anterior end to secretory-excretory pore = 99.7 ± 2.5 (96 to 103) µm; maximum body width = 15.2 ± 0.4 (15 to 16) µm; body width at anus = 10.1 ± 1 (8 to 11) µm; tail length = 62.0 ± 6.9 (51 to 74) µm; hyaline part of tail = 44.0 ± 1.8 (40 to 47) µm. The egg measurements for 11 individuals were length = 102.5 ± 7.9 (93 to 119) µm; width = 39.3 ± 4.2 (33 to 46) µm; length/width = 2.6 ± 0.3 (2.0 to 3.1). The morphology, morphometric characters and molecular data of the population of H. koreana isolated from bamboo in Iran are in agreement with those previously reported for this species (Vovlas et al., 1992; Mundo-Ocampo et al., 2008). At present, five species of Heterodera belonging to the Cyperi and Afenestrata groups were reported from bamboo, H. bamboosi (Kaushal and Swarup, 1988; Wouts and Baldwin, 1998) on Bambusa sp. from India; H. koreana on P. pubescence, P. aurea, and P. nigra from South Korea and the United States; and H. hainanensis (Zhuo et al., 2013), H. fengi (Wang et al., 2013), and H. guangdongensis (Zhuo et al., 2014) on P. pubescence from China; thus showing host suitability of bamboo for at least five species of cyst-forming nematodes. A greenhouse test performed by planting rice seed cv. Hashemi in soil containing H. koreana showed successful multiplication of Korean cyst nematode on rice seedlings after 2 mon. The exact date of the establishment of bamboo plantation in LARS is not precisely clear, but it indicates that the Korean cyst nematode was most likely brought with the imported bamboo seedlings from unknown origin several decades ago. According to our best knowledge, this is the first report of occurrence of H. koreana from Iran. So far the Korean cyst nematode was reported from South Korea, Thailand, and the United States, Florida (from nurseries); this study includes the distribution of this cyst-forming nematode in Iran and expands the information of the occurrence of H. koreana for the world.     

Evolutionary history of the Afro-Madagascan Ixora species (Rubiaceae): species diversification and distribution of key morphological traits inferred from dated molecular phylogenetic trees

Background and Aims

Previous work on the pantropical genus Ixora has revealed an Afro-Madagascan clade, but as yet no study has focused in detail on the evolutionary history and morphological trends in this group. Here the evolutionary history of Afro-Madagascan Ixora spp. (a clade of approx. 80 taxa) is investigated and the phylogenetic trees compared with several key morphological traits in taxa occurring in Madagascar.

Methods

Phylogenetic relationships of Afro-Madagascan Ixora are assessed using sequence data from four plastid regions (petD, rps16, rpoB-trnC and trnL-trnF) and nuclear ribosomal external transcribed spacer (ETS) and internal transcribed spacer (ITS) regions. The phylogenetic distribution of key morphological characters is assessed. Bayesian inference (implemented in BEAST) is used to estimate the temporal origin of Ixora based on fossil evidence.

Key Results

Two separate lineages of Madagascan taxa are recovered, one of which is nested in a group of East African taxa. Divergence in Ixora is estimated to have commenced during the mid Miocene, with extensive cladogenesis occurring in the Afro-Madagascan clade during the Pliocene onwards.

Conclusions

Both lineages of Madagascan Ixora exhibit morphological innovations that are rare throughout the rest of the genus, including a trend towards pauciflorous inflorescences and a trend towards extreme corolla tube length, suggesting that the same ecological and selective pressures are acting upon taxa from both Madagascan lineages. Novel ecological opportunities resulting from climate-induced habitat fragmentation and corolla tube length diversification are likely to have facilitated species radiation on Madagascar.     

Molecular phylogeny and biogeography of the fern genus Pteris (Pteridaceae)

Background and Aims

Pteris (Pteridaceae), comprising over 250 species, had been thought to be a monophyletic genus until the three monotypic genera Neurocallis, Ochropteris and Platyzoma were included. However, the relationships between the type species of the genus Pteris, P. longifolia, and other species are still unknown. Furthermore, several infrageneric morphological classifications have been proposed, but are debated. To date, no worldwide phylogenetic hypothesis has been proposed for the genus, and no comprehensive biogeographical history of Pteris, crucial to understanding its cosmopolitan distribution, has been presented.

Methods

A molecular phylogeny of Pteris is presented for 135 species, based on cpDNA rbcL and matK and using maximum parsimony, maximum likelihood and Bayesian inference approaches. The inferred phylogeny was used to assess the biogeographical history of Pteris and to reconstruct the evolution of one ecological and four morphological characters commonly used for infrageneric classifications.

Key Results

The monophyly of Pteris remains uncertain, especially regarding the relationship of Pteris with Actiniopteris + Onychium and Platyzoma. Pteris comprises 11 clades supported by combinations of ecological and morphological character states, but none of the characters used in previous classifications were found to be exclusive synapomorphies. The results indicate that Pteris diversified around 47 million years ago, and when species colonized new geographical areas they generated new lineages, which are associated with morphological character transitions.

Conclusions

This first phylogeny of Pteris on a global scale and including more than half of the diversity of the genus should contribute to a new, more reliable infrageneric classification of Pteris, based not only on a few morphological characters but also on ecological traits and geographical distribution. The inferred biogeographical history highlights long-distance dispersal as a major process shaping the worldwide distribution of the species. Colonization of different niches was followed by subsequent morphological diversification. Dispersal events followed by allopatric and parapatric speciation contribute to the species diversity of Pteris.     

The description of a new species of the Neotropical land crab genus Gecarcinus Leach, 1814 (Crustacea,Decapoda, Brachyura,Gecarcinidae)

In this contribution a new species of the land crab genus Gecarcinus Leach, 1814, from the Neotropical Pacific coast of South America is described and illustrated. In addition to its unique body color, Gecarcinus nobilii sp. n. is distinguished from congeners by a distinctly wider carapace front and differences in the shape of the infraorbital margin. The new species is not isolated from Gecarcinus populations from the Pacific coast of Central America by an insurmountable geographic barrier. Considering the closure of the Panamanian Isthmus as a calibration point for morphological divergence between the trans-isthmian mainland populations of Gecarcinus, the virtual lack of morphological differentiation (other than color) between them and the distinctness of G. nobilii sp. n. suggests that G. nobilii sp. n. evolved from a common ancestor before the Isthmus closed.     

Canine Wound Myiasis Caused by Lucilia sericata (Diptera: Calliphoridae) in Korea

Myiasis is a relatively common infection of animals kept as pets, although only 1 case of canine myiasis has been described so far in the Republic of Korea. In the present study, we report an additional case of canine wound myiasis with identification of its causative agent, Lucilia sericata. An 8-year-old male Siberian husky dog was referred with anorexia, vomiting, and diarrhea to the Chungbuk National University Veterinary Medical Center, Cheongju-si (city), Chungcheongbuk-do (province), Korea in July 2013. Physical examination indicated the patient had a deep wound filled with a maggot swarm as a left gluteal lesion. A total of 216 maggots were removed by forceps, and the wounded area was sponged with gauzes and disinfected with 70% alcohol and a povidone-iodine solution. After daily care and suturing the wound, the patient was discharged at day 19 after admission. Recovered worms possessed morphological characteristics similar to those of L. sericata, namely, a sub-cylindrical body with 6–8 lobed anterior spiracles, round shaped with a button surrounded by a peritremal ring with no gaps, and similar distances between dorsal, median, and outer papillae of the 12th segment. Additionally, cox1 partial sequences (528 bp) obtained in the present study showed 100% identity with those of L. sericata (GenBank no. {"type":"entrez-nucleotide","attrs":{"text":"KT272854.1","term_id":"992320795","term_text":"KT272854.1"}}KT272854.1). L. sericata is indicated as a pathogen of myiasis infection not only in humans, but also in animals kept as pets in Korea.     

Glandulocalyx upatoiensis, a fossil flower of Ericales (Actinidiaceae/Clethraceae) from the Late Cretaceous (Santonian) of Georgia, USA

Background and Aims

Ericales are a major group of extant asterid angiosperms that are well represented in the Late Cretaceous fossil record, mainly by flowers, fruits and seeds. Exceptionally well preserved fossil flowers, here described as Glandulocalyx upatoiensis gen. & sp. nov., from the Santonian of Georgia, USA, yield new detailed evidence of floral structure in one of these early members of Ericales and provide a secure basis for comparison with extant taxa.

Methods

The floral structure of several fossil specimens was studied by scanning electron microscopy (SEM), light microscopy of microtome thin sections and synchrotron-radiation X-ray tomographic microscopy (SRXTM). For direct comparisons with flowers of extant Ericales, selected floral features of Actinidiaceae and Clethraceae were studied with SEM.

Key Results

Flowers of G. upatoiensis have five sepals with quincuncial aestivation, five free petals with quincuncial aestivation, 20–28 stamens arranged in a single series, extrorse anther orientation in the bud, ventral anther attachment and a tricarpellate, syncarpous ovary with three free styles and numerous small ovules on axile, protruding-diffuse and pendant placentae. The calyx is characterized by a conspicuous indumentum of large, densely arranged, multicellular and possibly glandular trichomes.

Conclusions

Comparison with extant taxa provides clear evidence for a relationship with core Ericales comprised of the extant families Actinidiaceae, Roridulaceae, Sarraceniaceae, Clethraceae, Cyrillaceae and Ericaceae. Within this group, the most marked similarities are with extant Actinidiaceae and, to a lesser degree, with Clethraceae. More detailed analyses of the relationships of Glandulocalyx and other Ericales from the Late Cretaceous will require an improved understanding of the morphological features that diagnose particular extant groups defined on the basis of molecular data.     

On Afromantispa and Mantispa (Insecta,Neuroptera, Mantispidae): elucidating generic boundaries

The genus Afromantispa Snyman & Ohl, 2012 was recently synonymised with Mantispa Illiger, 1798 by Monserrat (2014). Here morphological evidence is presented in support of restoring the genus Afromantispa stat. rev. to its previous status as a valid and morphologically distinct genus. Twelve new combinations (comb. n.) are proposed as species of Afromantispa including three new synonyms.     

Gymnosperm B-sister genes may be involved in ovule/seed development and,in some species,in the growth of fleshy fruit-like structures

Background and Aims

The evolution of seeds together with the mechanisms related to their dispersal into the environment represented a turning point in the evolution of plants. Seeds are produced by gymnosperms and angiosperms but only the latter have an ovary to be transformed into a fruit. Yet some gymnosperms produce fleshy structures attractive to animals, thus behaving like fruits from a functional point of view. The aim of this work is to increase our knowledge of possible mechanisms common to the development of both gymnosperm and angiosperm fruits.

Methods

B-sister genes from two gymnosperms (Ginkgo biloba and Taxus baccata) were isolated and studied. The Ginkgo gene was also functionally characterized by ectopically expressing it in tobacco.

Key Results

In Ginkgo the fleshy structure derives from the outer seed integument and the B-sister gene is involved in its growth. In Taxus the fleshy structure is formed de novo as an outgrowth of the ovule peduncle, and the B-sister gene is not involved in this growth. In transgenic tobacco the Ginkgo gene has a positive role in tissue growth and confirms its importance in ovule/seed development.

Conclusions

This study suggests that B-sister genes have a main function in ovule/seed development and a subsidiary role in the formation of fleshy fruit-like structures when the latter have an ovular origin, as occurs in Ginkgo. Thus, the ‘fruit function’ of B-sister genes is quite old, already being present in Gymnosperms as ancient as Ginkgoales, and is also present in Angiosperms where a B-sister gene has been shown to be involved in the formation of the Arabidopsis fruit.     

Organellar genomes of the four-toothed moss,Tetraphis pellucida

Background

Mosses are the largest of the three extant clades of gametophyte-dominant land plants and remain poorly studied using comparative genomic methods. Major monophyletic moss lineages are characterised by different types of a spore dehiscence apparatus called the peristome, and the most important unsolved problem in higher-level moss systematics is the branching order of these peristomate clades. Organellar genome sequencing offers the potential to resolve this issue through the provision of both genomic structural characters and a greatly increased quantity of nucleotide substitution characters, as well as to elucidate organellar evolution in mosses. We publish and describe the chloroplast and mitochondrial genomes of Tetraphis pellucida, representative of the most phylogenetically intractable and morphologically isolated peristomate lineage.

Results

Assembly of reads from Illumina SBS and Pacific Biosciences RS sequencing reveals that the Tetraphis chloroplast genome comprises 127,489 bp and the mitochondrial genome 107,730 bp. Although genomic structures are similar to those of the small number of other known moss organellar genomes, the chloroplast lacks the petN gene (in common with Tortula ruralis) and the mitochondrion has only a non-functional pseudogenised remnant of nad7 (uniquely amongst known moss chondromes).

Conclusions

Structural genomic features exist with the potential to be informative for phylogenetic relationships amongst the peristomate moss lineages, and thus organellar genome sequences are urgently required for exemplars from other clades. The unique genomic and morphological features of Tetraphis confirm its importance for resolving one of the major questions in land plant phylogeny and for understanding the evolution of the peristome, a likely key innovation underlying the diversity of mosses. The functional loss of nad7 from the chondrome is now shown to have occurred independently in all three bryophyte clades as well as in the early-diverging tracheophyte Huperzia squarrosa.     

Arabinogalactan protein-rich cell walls,paramural deposits and ergastic globules define the hyaline bodies of rhinanthoid Orobanchaceae haustoria

Background and Aims

Parasitic plants obtain nutrients from their hosts through organs called haustoria. The hyaline body is a specialized parenchymatous tissue occupying the central parts of haustoria in many Orobanchaceae species. The structure and functions of hyaline bodies are poorly understood despite their apparent necessity for the proper functioning of haustoria. Reported here is a cell wall-focused immunohistochemical study of the hyaline bodies of three species from the ecologically important clade of rhinanthoid Orobanchaceae.

Methods

Haustoria collected from laboratory-grown and field-collected plants of Rhinanthus minor, Odontites vernus and Melampyrum pratense attached to various hosts were immunolabelled for cell wall matrix glycans and glycoproteins using specific monoclonal antibodies (mAbs).

Key Results

Hyaline body cell wall architecture differed from that of the surrounding parenchyma in all species investigated. Enrichment in arabinogalactan protein (AGP) epitopes labelled with mAbs LM2, JIM8, JIM13, JIM14 and CCRC-M7 was prominent and coincided with reduced labelling of de-esterified homogalacturonan with mAbs JIM5, LM18 and LM19. Furthermore, paramural bodies, intercellular deposits and globular ergastic bodies composed of pectins, xyloglucans, extensins and AGPs were common. In Rhinanthus they were particularly abundant in pairings with legume hosts. Hyaline body cells were not in direct contact with haustorial xylem, which was surrounded by a single layer of paratracheal parenchyma with thickened cell walls abutting the xylem.

Conclusions

The distinctive anatomy and cell wall architecture indicate hyaline body specialization. Altered proportions of AGPs and pectins may affect the mechanical properties of hyaline body cell walls. This and the association with a transfer-like type of paratracheal parenchyma suggest a role in nutrient translocation. Organelle-rich protoplasts and the presence of exceptionally profuse intra- and intercellular wall materials when attached to a nitrogen-fixing host suggest subsequent processing and transient storage of nutrients. AGPs might therefore be implicated in nutrient transfer and metabolism in haustoria.     

Is Drosera meristocaulis a pygmy sundew? Evidence of a long-distance dispersal between Western Australia and northern South America

Background and aims

South America and Oceania possess numerous floristic similarities, often confirmed by morphological and molecular data. The carnivorous Drosera meristocaulis (Droseraceae), endemic to the Neblina highlands of northern South America, was known to share morphological characters with the pygmy sundews of Drosera sect. Bryastrum, which are endemic to Australia and New Zealand. The inclusion of D. meristocaulis in a molecular phylogenetic analysis may clarify its systematic position and offer an opportunity to investigate character evolution in Droseraceae and phylogeographic patterns between South America and Oceania.

Methods Drosera meristocaulis

was included in a molecular phylogenetic analysis of Droseraceae, using nuclear internal transcribed spacer (ITS) and plastid rbcL and rps16 sequence data. Pollen of D. meristocaulis was studied using light microscopy and scanning electron microscopy techniques, and the karyotype was inferred from root tip meristem.

Key Results

The phylogenetic inferences (maximum parsimony, maximum likelihood and Bayesian approaches) substantiate with high statistical support the inclusion of sect. Meristocaulis and its single species, D. meristocaulis, within the Australian Drosera clade, sister to a group comprising species of sect. Bryastrum. A chromosome number of 2n = approx. 32–36 supports the phylogenetic position within the Australian clade. The undivided styles, conspicuous large setuous stipules, a cryptocotylar (hypogaeous) germination pattern and pollen tetrads with aperture of intermediate type 7–8 are key morphological traits shared between D. meristocaulis and pygmy sundews of sect. Bryastrum from Australia and New Zealand.

Conclusions

The multidisciplinary approach adopted in this study (using morphological, palynological, cytotaxonomic and molecular phylogenetic data) enabled us to elucidate the relationships of the thus far unplaced taxon D. meristocaulis. Long-distance dispersal between southwestern Oceania and northern South America is the most likely scenario to explain the phylogeographic pattern revealed.     

Balantidium honghuensis n. sp. (Ciliophora: Trichostomatidae) from the Rectum of Rana nigromaculata and R. limnocharis from Honghu Lake,China

A new trichostome ciliate, Balantidium honghuensis n. sp., was isolated from the recta of Rana nigromaculata and R. limnocharis during parasite surveys in Honghu Lake, Hubei Province, central China in summer of 2010 and 2011. Its detailed morphometric characters based on LM and SEM studies were described herein. The organism is oval in shape and thickly ciliated. The vestibulum is "V" shaped and occupies about 1/3 to 2/5 of the body length. The vestibular and nearby regions possess strong peripheral fibers which form a marked axial fiber about the cytopharynx. More than 10 contractile vacuoles are distributed along the periphery of the latter body. Comparisions were made between this new species and B. sinensis Nie, 1935. They were discriminated from each other in terms of general body forms, body size, and vestibulum shapes. Besides, special attention was paid to its high-speed daughter swarmers which we believed to be the infective stage of B. honghuensis. Possible infection routes of anura amphibian balantidia were discussed.