A case of mistaken identity,Opuntia abjecta,long-lost in synonymy under the Caribbean species,O. triacantha,and a reassessment of the enigmatic O. cubensis

Opuntia abjecta and O. militaris have been placed in synonymy under the Caribbean species O. triacantha for the past 30 years. Recent molecular phylogenetic evidence has shown, however, that O. abjecta and O. triacantha are actually in two very different clades suggesting that the Floridian endemic O. abjecta should be recognized as a distinct species. Here, we summarize major morphological differences between O. abjecta and O. triacantha. We also include new sequence data from the rare Cuban taxon, O. militaris, in a molecular phylogenetic analysis to determine its relationship to O. triacantha and O. abjecta. We discuss the putative hybrid taxa O. cubensis and O. ochrocentra, which currently are treated as synonyms. We also show through analysis of morphological and molecular characters that these two taxa were derived from two independent origins from divergent maternal progenitors, confirming that O. ochrocentra should not be treated as synonymous with O. cubensis. A key is provided for identifying these taxonomically confusing taxa and their close relatives. This study emphasizes the distinctions among O. abjecta, O. militaris, and O. triacantha and illustrates that extreme caution must be employed when using herbarium specimens for identifying species of Opuntia. It also indicates that broad phytogeographic assumptions regarding species’ relationships in Opuntia may sometimes be misleading. Hybridization and polyploidy are common in Opuntia and have played a role in the formation of new species in this group as well. A neotype is here designated for O. triacantha.     

Chromosome numbers in callirhoe (Malvaceae)

Forty-four chromosome counts from the North American genusCallirhoe are reported, including first-recorded counts ofC. alcaeoides, C. digitata, C. bushii, C. triangulata, andC. involucrata var.tenuissima. Information concerning chromosome numbers from present and previous reports is summarized and evaluated. Observations are presented on meiosis for the genus in general, for male sterile individuals of gynodioecious species, and for selected F₁ hybrids. Pollen fertility data are recorded for the latter. Chromosomally three species groups are recognized: an exinvolucellate, diploid species group withn=14; an involucellate, tetraploid and octoploid species pair,n=28 and 56; and an involucellate, diploid and tetraploid species group withn=15 and 30. Intrageneric relationships and those within the tribe Malveae subtribe Malvinae are discussed.     

MOLECULAR SYSTEMATICS OFLECANORASUBGENUSPLACODIUM

A first hypothesis for the phylogeny ofLecanorasubgen.Placodiumis presented by using molecular data. Previous evolutionary ideas and classification concepts for this group with non-molecular data are re-investigated using DNA sequence data from the nuclear ITS and 5.8S regions. UsingProtoparmeliaas an outgroup, theLecanora subfuscagroup together with theL. rupicolagroup appear as a sister group to assemblages with lobate species. Subgen.Placodium, as currently accepted, is not monophyletic. Molecular data suggest that theLecanora dispersagroup and theL. polytropagroup are widened by lobate species and there is evidence from the ITS data that the monotypic genusArctopeltisPoelt is closely related to theL. dispersagroup. A congruence between molecular data and secondary chemistry supports the broader concept of theL. dispersagroup suggested by the molecular data.     

Flavonoids of gaura triangulata

Ten flavonoids were obtained from Gaura triangulata including luteolin and luteolin 7-glycoside derivatives which are atypical for the family Onagraceae. Apigenin-based C-glycosylflavones, previously reported from the Onagraceae in the monogeneric tribe Circaeeae, have also been identified. The flavonoid profile of G. triangulata is distinctive for the family since previous studies of the Onagraceae reported primarily flavonols.     

Quinic acid derivatives from Saussurea triangulata attenuates glutamate-induced neurotoxicity in primary cultured rat cortical cells

The leaves of Saussurea triangulata (Compositae) have been eaten with rice as a wrapping vegetable for preventing neuro-aging. However, the components responsible for the neuroprotective effects of S. triangulata still remain unidentified. In the process of investigating the neuroprotective activity of S. triangulata, we found that a methanol extract of S. triangulata exhibited significant protection against glutamate-induced toxicity in primary cultured rat cortical cells. Three quinic acid derivatives were isolated from the n-BuOH fraction of S. triangulata. Among these three quinic acid derivatives, methyl 5-caffeoylquinic acid (3) exhibited significant neuroprotective activities against glutamate-induced toxicity exhibiting cell viability of about 50%, at concentrations ranging from 0.1 μM to 10 μM. Therefore, the neuroprotective effect of S. triangulata might be due to the inhibition of glutamate-induced toxicity by the quinic acid derivatives from S. triangulata.     

Molecular phylogeny and phylogeography of ricefishes (Teleostei: Adrianichthyidae: Oryzias) in Sri Lanka

Ricefishes of the genus Oryzias occur commonly in the fresh and brackish waters in coastal lowlands ranging from India across Southeast Asia and on to Japan. Among the three species of Oryzias recorded from peninsular India, two widespread species, O. carnaticus and O. dancena, have previously been reported from Sri Lanka based on museum specimens derived from a few scattered localities. However, members of the genus are widespread in the coastal lowlands of Sri Lanka, a continental island separated from India by the shallow Palk Strait. Although recent molecular phylogenies of Adrianichthyidae represent near‐complete taxon representation, they lack samples from Sri Lanka. Here, based on sampling at 13 locations representative of the entire geographic and climatic regions of the island''s coastal lowlands, we investigate for the first time the molecular phylogenetic relationships and phylogeography of Sri Lankan Oryzias based on one nuclear and two mitochondrial markers. Sri Lankan Oryzias comprise two distinct non‐sister lineages within the javanicus species group. One of these is represented by samples exclusively from the northern parts of the island; it is recognized as O. dancena. This lineage is recovered as the sister group to the remaining species in the javanicus group. The second lineage represents a species that is widespread across the island''s coastal lowlands. It is recovered as the sister group of O. javanicus and is identified as O. cf. carnaticus. Ancestral‐range estimates suggest two independent colonizations of Indian subcontinent and Sri Lanka by widespread ancestral species of Oryzias during two discrete temporal windows: late Miocene and Plio‐Pleistocene. No phylogeographic structure is apparent in Sri Lankan Oryzias, suggesting that there are no strong barriers to gene flow and dispersal along the coastal floodplains, as is the case also for other generalist freshwater fishes in the island.     

Genetic relations among basil taxa (Ocimum L.) based on molecular markers, nuclear DNA content, and chromosome number

Twenty-eight basil accessions including six Ocimum species and six botanical varieties or cultivars of O. basilicum were studied using molecular markers, nuclear DNA content, and chromosome counting. This is the first study reporting the nuclear DNA content in the genus Ocimum. The results supported the existence of more infrageneric groups within the genus. The section Ocimum was further divided into two separate clades. The first clade contained the accessions belonging to different botanical varieties and cultivars of O. basilicum as well as O. minimum, indicating that the separate species rank of O. minimum was not justified. The second clade, comprising O. americanum, O. africanum, and two O. basilicum var. purpurascens accessions, could represent a set of allopolyploid species sharing some common parental genomes. O. tenuiflorum was the most divergent species according to genetic distance; it had the smallest genome size, organized in small chromosomes, and the lowest chromosome number. Chromosome data obtained in our research could indicate that the basic chromosome number for species belonging to section Ocimum is x = 12. This suggestion implies that species belonging to O. basilicum clade are tetraploids, while species belonging to O. americanum clade are hexaploids. It seems that the basic chromosome number for O. gratissimum could be x = 10 and for O. tenuiflorum x = 9. The differences in genome size and chromosome number among Ocimum species indicate that evolution of their genomes was accompanied by both sequence deletion/amplification and chromosome rearrangements and polyploidization.     

First demonstration of Strongyloides parasite from an imported pet meerkat – Possibly a novel species in the stercoralis/procyonis group

Strongyloides is a genus of parasitic nematodes of vertebrates that contains over 50 species, each with a variable host range. A recent molecular phylogenetic analysis on this genus showed that Strongyloides spp. from various carnivore hosts form a strongly supported clade together with Strongyloides stercoralis, a major pathogen of humans and dogs (named the “stercoralis/procyonis group”). In the present study, we obtained DNA sequencing data of Strongyloides sp. isolated from an imported meerkat (Suricata suricatta). Based on the phylogenetic analysis, we considered this a new member of the stercoralis/procyonis group. This study represents the first isolation and molecular characterization of a Strongyloides species from hosts belonging to the family Herpestidae (mongooses and meerkat). However, whether the meerkat serves as a natural host of this Strongyloides species remains to be investigated.     

Targeted lipidomics reveals a novel role for glucosylceramides in glucose response

The addition of excess glucose to the diet drives a coordinated response of lipid metabolism pathways to tune the membrane composition to the altered diet. Here, we have employed targeted lipidomic approaches to quantify the specific changes in the phospholipid and sphingolipid populations that occur in elevated glucose conditions. The lipids within wild-type Caenorhabditis elegans are strikingly stable with no significant changes identified in our global mass spectrometry–based analysis. Previous work has identified ELO-5, an elongase that is critical for the synthesis of monomethyl branched-chain fatty acids (mmBCFAs), as essential for surviving elevated glucose conditions. Therefore, we performed targeted lipidomics on elo-5 RNAi-fed animals and identified several significant changes in these animals in lipid species that contain mmBCFAs as well as in species that do not contain mmBCFAs. Of particular note, we identified a specific glucosylceramide (GlcCer 17:1;O2/22:0;O) that is also significantly upregulated with glucose in wild-type animals. Furthermore, compromising the production of the glucosylceramide pool with elo-3 or cgt-3 RNAi leads to premature death in glucose-fed animals. Taken together, our lipid analysis has expanded the mechanistic understanding of metabolic rewiring with glucose feeding and has identified a new role for the GlcCer 17:1;O2/22:0;O.     

Chromosomes of Asian cyprinid fishes: Variable karyotype patterns and evolutionary trends in the genus Osteochilus (Cyprinidae, Labeoninae, “Osteochilini”)

The Cyprinidae family is a highly diversified but demonstrably monophyletic lineage of cypriniform fishes. Among them, the genus Osteochilus contains 35 recognized valid species distributed from India, throughout Myanmar, Laos, Thailand, Malaysia, Indonesian archipelago to southern China. In this study, karyotypes and other chromosomal characteristics of five Osteochilus species occurring in Thailand, namely O. lini, O. melanopleura, O. microcephalus, O. vittatus and O. waandersii were examined using conventional and molecular cytogenetic protocols. Our results showed they possessed diploid chromosome number (2n) invariably 2n = 50, but the ratio of uni- and bi-armed chromosomes was highly variable among their karyotypes, indicating extensive chromosomal rearrangements. Only one chromosome pair bearing 5S rDNA sites occurred in most species, except O. melanopleura, where two sites were detected. In contrast, only one chromosomal pair bearing 18S rDNA sites were observed among their karyotypes, but in different positions. These cytogenetic patterns indicated that the cytogenomic divergence patterns of these Osteochilus species were largely corresponding to the inferred phylogenetic tree. Similarly, different patterns of the distributions of rDNAs and microsatellites across genomes of examined species as well as their different karyotype structures indicated significant evolutionary differentiation of Osteochilus genomes.     

Single versus multiple enemies and the impact on biological control of spider mites in cassava fields in West-Africa

To determine whether to use single or multiple predator species for biological pest control requires manipulative field experiments. We performed such tests in Benin (West Africa) in cassava fields infested by the cassava green mite Mononychellus tanajoa, and the cotton red mite Oligonychus gossypii. These fields also harboured the cassava apex-inhabiting predator Typhlodromalus aripo and either the leaf-inhabiting predator Amblydromalus manihoti or Euseius fustis. We manipulated predator species composition on individual plants to determine their effect on prey and predator densities. In fields with T. aripo plus A. manihoti, M. tanajoa densities were reduced by T. aripo alone or together with A. manihoti, but neither of these predators, alone or together, reduced O. gossypii densities. In fields with T. aripo plus E. fustis, T. aripo alone or together with E. fustis exerted significant control over O. gossypii, but weak control over M. tanajoa. Densities of any of the predator species were not affected by co-occurring predator species, suggesting a minor role for intraguild predation in the field, contrary to earlier experiments on small plants in the laboratory. We conclude that (1) T. aripo is the most effective predator species in suppressing M. tanajoa, (2) two predator species, T. aripo and E. fustis, are needed to suppress O. gossypii, and (3) predator species together on the same plant do not negatively affect each other nor the extent to which they control their prey. We argue that intraguild predation is reduced due to partial niche separation among predator species.     

Molecular Phylogeny of Weakfish Species of the Stellifer Group (Sciaenidae,Perciformes) of the Western South Atlantic Based on Mitochondrial and Nuclear Data

The phylogenetic relationships within the Stellifer group of weakfishes (Stellifer, Odontoscion, Ophioscion, and Bairdiella) were evaluated using 2723 base pairs comprising sequences of nuclear (rhodopsin, TMO-4C4, RAG-1) and mitochondrial (16S rRNA and COI) markers obtained from specimens of nine species. Our results indicate a close relationship between Bairdiella and Odontoscion, and also that the genus Stellifer is not monophyletic, but rather that it consists of two distinct lineages, one clade containing S. microps/S. naso/S. brasiliensis and the other, S. rastrifer/S. stellifer/Stellifer sp. B, which is closer to Ophioscion than the former clade. The O. punctatissimus populations from the northern and southern Brazilian coast were also highly divergent in both nuclear (0.8% for rhodopsin and 0.9% for RAG-1) and mitochondrial sequences (2.2% for 16S rRNA and 7.3% for COI), which we conclude is consistent with the presence of two distinct species. The morphological similarities of the members of the Stellifer group is reinforced by the molecular data from both the present study and previous analyses, which have questioned the taxonomic status of the Stellifer group. If, on the one hand, the group is in fact composed of four genera (Stellifer, Ophioscion, Odontoscion, and Bairdiella), one of the two Stellifer clades should be reclassified as a new genus. However, if the close relationship and the reduced genetic divergence found within the group is confirmed in a more extensive study, including representatives of additional taxa, this, together with the morphological evidence, would support downgrading the whole group to a single genus. Obviously, these contradictory findings reinforce the need for a more systematic taxonomic revision of the Stellifer group as a whole.     

Species Diversity in the Parasitoid Genus Asobara (Hymenoptera: Braconidae) from the Native Area of the Fruit Fly Pest Drosophila suzukii (Diptera: Drosophilidae)

Drosophila suzukii (Matsumura), commonly known as Spotted Wing Drosophila (SWD), is a worldwide serious economic threat to the production of berries and stone fruits. The chemical control widely used against this pest is often not able to preventing yield losses because wild flora offers an abundance of fruits to D. suzukii where the pest is able to reproduce and from where it recolonizes neighbouring cultivated fields. Alternatively, within Integrated Pest Management protocols for D. suzukii, biological control could play a key role by reducing its populations particularly in non-cultivated habitats, thus increasing the effectiveness and reducing the side negative effects of other management strategies. Because of the scarcity and of the low efficiency of autochthonous parasitoids in the new invaded territories, in the last few years, a number of surveys started in the native area of D. suzukii to find parasitoid species to be evaluated in quarantine structures and eventually released in the field, following a classical biological control approach. This paper reports the results of these surveys carried out in South Korea and for the first time in China. Among the parasitoids collected, those belonging to the genus Asobara Foerster resulted dominant both by number and species diversity. By combining morphological characters and the mitochondrial COI gene as a molecular marker, we identified seven species of Asobara, of which two associated with D. suzukii, namely A. japonica and A leveri, and five new to science, namely Asobara brevicauda, A. elongata, A mesocauda, A unicolorata, A. triangulata. Our findings offer new opportunity to find effective parasitoids to be introduced in classical biological control programmes in the territories recently invaded by D. suzukii.     

Distribution and decline of endangered herbaceous heathland species in relation to the chemical composition of the soil

High atmospheric deposition of ammonium affects the physical and chemical status of the soil, increasing nitrogen availability, soil acidity and the mobilization of toxic metal ions. To investigate whether and how the decline of several herbaceous plant species in Dutch heathlands is associated with these processes, the chemical composition of the soil on which these species grow has been compared with the soil on which heathland species such asCalluna vulgaris (L.) Hull,Erica tetralix L. andMolinea caerulea (L.) Moench dominate. The discrimination between both soil types was primarily based on differences in pH (H₂O), pH (NaCl) and the aluminium/calcium ratio in the waterextracts. Within the group of endangered herbaceous heathland species these soil parameters also varied. This led to a division into 4 groups of species:

u

Dominating species growing on acid soils

Herbaceous species growing together with dominating species on acid soils

Herbaceous species growing together with dominating species on moderately acid soils

Herbaceous species growing together with dominating species on weakly acid soils.

This study indicated that, unlike the decline of heather species, the decline of herbaceous species is not likely to be due to increased competition from grass species as a result of eutrophication. Soil acidification and the changed mineral balance in the soil are most likely to be responsible for the decline of all three groups of herbaceous plant species. ei]R F Huettl     

Mortality of the earthworm Eisenia fetida (Savigny) presented to the terrestrial planarian Ártioposthia triangulata (Dendy) (Tricladida: Terricola)

Ártioposthia triangulata is a terrestrial planarian that feeds on earthworms. Up to 76% of field collected A. triangulata fed on Eisenia fetida earthworms at 10°C in the laboratory. In one experiment, the feeding rate declined from 63% of earthworms attacked to 36% and 34% in the first, second and third feeding opportunities over a week. The average number of E. fetida eaten was 1.4 per planarian per week. The gain in weight of individual A. triangulata was significantly related to the amount of earthworm tissue lost during the feeding process. Over a one week period, the amount of earthworm tissue lost was related to the total amount presented to the planarians but not to their size. Frequency of attack was, however, related to planarian size. The results are discussed in relation to an hypothetical population of earthworms in pasture. It is concluded that the results support the contention that A. triangulata could seriously deplete earthworm populations.     

Biogeography of theOxalis tuberosa alliance

TheOxalis tuberosa alliance is a group of morphologically similarOxalis species allied to the Andean tuber crop oca,O. tuberosa. Originally described by cytologists as a dozen species sharing a base chromosome number rare inOxalis (x = 8), the alliance as defined here includes additional species for which cytological information is not yet available but which are supported as members on molecular and/or morphological grounds. The alliance includes members found in the Andean region from Venezuela to northern Argentina, with one species at high elevations in Central America. They occur from the high Andean steppes (páramo and puna) to the cloud forests of middle elevations and include both restricted endemics and variable widespread species complexes. Geographical and altitudinal distributions of members of the alliance and selectedOxalis species outside the alliance were compared with a combined phylogenetic analysis of DNA sequence data of ITS and ncpGS (chloroplast-expressed glutamine synthetase). Groups within the alliance (i.e., major clades on the molecular trees) occur across widespread, overlapping regions in the Andes, with only partial ecological separation. The hypothesis that theO. tuberosa alliance may have developed in the Andes of southern Peru and northwestern Bolivia and radiated southward and, especially, northward along the Andean axis is suggested by patterns of distributions of members of the alliance and outgroups. In spite of uncertain species delimitations, it is clear that the alliance includes many endemic species and ecotypes that have very restricted distributions. As relatives of the Andean tuber cropOxalis tuberosa, the genetic diversity represented by this geographical variability should be a high priority for conservation.     

Stable isotope analysis,field observations and synthesis experiments suggest that Odontia is a non-mycorrhizal sister genus of Tomentella and Thelephora

Ectomycorrhizal symbiosis has evolved multiple times in plants and fungi, but the trophic status of certain fungal groups remains poorly understood due to their unculturability or ambiguous interpretation of biotrophic associations. Combining field observations, molecular identification of root tips, synthesis experiments and analysis of stable isotopes, we address the lifestyle of Tomentella crinalis and another species closely related to T. fibrosa that represents a sister group to the ectomycorrhizal genera Tomentella and Thelephora. Based on molecular analyses these two and other related species are moved to the genus Odontia. In Odontia species, ectomycorrhizal associations were not observed in nature or in various synthesis experiments. Although Odontia species normally fruit in old forests, Odontia ferruginea has also been identified from a deep belowground mine. Unlike saprotrophs, Odontia spp. and ectomycorrhizal fungi were not enriched in ¹³C compared with their woody fruiting substratum, suggesting that wood is not their major energy source. In contrast to ectomycorrhizal fungi, Odontia species and saprotrophs were not enriched in ¹⁵N relative to their substratum. Taken together, we suggest that Odontia spp. are non-mycorrhizal, but their nutrition differs from typical wood-rotting Basidiomycota.