Microsatellite loci from Russula brevipes,a common ectomycorrhizal associate of several tree species in North America

Six microsatellite loci were isolated and characterized from genomic libraries enriched for (CA)_n (GA)_n (ATG)_n, and (CAG)_n, microsatellite motifs from Russula brevipes, a common ectomycorrhizal fungus that forms mutualisms with several species of trees in North America. The polymerase chain reaction primers were tested on 27 sporocarps of R. brevipes sampled in Douglas fir (Pseudotsuga menziesii), grey pine (Pinus sabiniana), and Sitka spruce (Picea sitchensis) stands. The number of alleles per locus ranged from two to 14 with expected heterozygosity values from 0.00 to 0.92 within populations. These are the first six microsatellite loci characterized from Russula brevipes that can be used for estimating genotypic diversity and population structure.     

Three new species of Euathlus Ausserer, 1875 (Araneae,Theraphosidae) from Argentina

ABSTRACT

Euathlus

Ausserer, 1875 is a South American genus of spiders of the family Theraphosidae known from Chile and Argentina. Three new species from Argentina: Euathlus mauryi sp. n. (from San Juan province), Euathlus grismadoi sp. n. (from La Rioja province), and Euathlus pampa sp. n. (from Salta province) are described here. New records of the previous species Euathlus diamante and Euathlus tenebrarum are contributed. The distribution of these new species expands the geographical distribution of the genus along the Andean hills, with Salta province as the northernmost record of the genus. A key is provided for identification of Euathlus species as well as a map with all the records in Argentina.     

Defence,growth and nutrient allocation in the tropical shrub Bauhinia brevipes (Leguminosae)

Herbivory in natural communities can be high, reducing the growth and reproduction of individual plants. To diminish the impact of herbivores, plants use a variety of defensive mechanisms. It is now recognized that the plant world is characterized by a proliferation of secondary metabolites, but models of the evolution of defence strategies assume that plants are constrained by finite resources, and that defences are costly. In the present study, the relationships between defence, growth and nutrient concentration in Bauhinia brevipes Vog. (Leguminosae) in south‐eastern Brazil were investigated. Patterns of herbivory and defence were examined for 170 B. brevipes individuals in 1997 and 1998. Leaf age influenced tannin concentration and herbivore attack on B. brevipes. Mature leaves had higher concentrations of tannins than young leaves, and young leaves were approximately 60% more likely to be attacked than mature leaves. Carbon and nitrogen content explained 36% of the variation in the percentage of attacked leaves in B. brevipes (y = 16.29 – 0.31 C + 0.25 N; r² = 0.36; F = 9.56; P < 0.0001). Tannins acted as defensive compounds on B. brevipes leaves against free‐feeding herbivores, but no clear pattern was observed against galling herbivores. The amounts of nitrogen, carbon, potassium, and aluminium explained approximately 69% of the variation in tannin concentration on B. brevipes leaves (y = 0.62 – 0.16 N – 0.36 K – 0.26 Al + 0.74 C; r² = 0.69; F = 21.18; P < 0.0001). We found an inverse relationship between shoot growth rates and tannin concentration in B. brevipes, indicating that the production of tannins may be costly, therefore offering some evidence for the trade‐off hypothesis. Nevertheless, the weak relationship observed between herbivore damage and tannin concentration indicates that other factors are also involved with herbivore pressure.     

Homoplastic evolution of external colouration in Asian stout newts (Pachytriton) inferred from molecular phylogeny

Wu, Y., Wang, Y., Jiang, K., Chen, X. & Hanken, J. (2009). Homoplastic evolution of external colouration in Asian stout newts (Pachytriton) inferred from molecular phylogeny.—Zoologica Scripta, 39, 9–22. The Asian stout newts of the genus Pachytriton (Salamandridae) inhabit montane streams in south-eastern China. Despite their abundance in the pet trade, the phylogeny and systematics of this genus are poorly understood. Colouration is often used to delimit species under the assumption that consistent chromatic differences characterize independent evolutionary lineages. We present the first phylogenetic study of Pachytriton that incorporates 2.35 kb of mitochondrial DNA (ND2, cytb) and 1.2 kb of nuclear sequence data (RAG-1) along with morphometric characters to infer evolutionary relationships and patterns of colour evolution among the three described species: Pachytriton brevipes, Pachytriton labiatus and Pachytriton archospotus. Our results support the monophyly of Pachytriton and recover P. archospotus as the sister taxon to P. brevipes. Monophyly of P. labiatus is significantly rejected: south-western populations are sister to the group of P. brevipes plus P. archospotus, whereas north-eastern populations nest with P. brevipes. The two geographic units are further separated by multivariate morphological analyses. South-western P. labiatus is the type species; misidentification of north-eastern populations as P. labiatus results from their similar colouration. An unspotted, dark brown dorsum is the likely ancestral state for the genus, whereas black-spotted colouration characterized the common ancestor of P. brevipes, P. archospotus, and north-eastern P. labiatus and was secondarily lost in the latter group. Homoplastic evolution and intraspecific variation render colour pattern in Pachytriton an unreliable character for delimiting species boundaries. North-eastern populations of P. labiatus are declining as the result of human collection and habitat destruction and are in urgent need of conservation protection.     

The Role of Natural Enemies in the Germination and Establishment of Pachira (Malvaceae) Trees in the Peruvian Amazon

Seeds from Pachira brevipes from white‐sand forest and Pachira insignis from clay forest were placed in a reciprocal transplant experiment that manipulated herbivore presence. Pachira insignis experienced 80 percent leaf loss in both habitats from herbivores, causing 79 percent mortality in white‐sand compared with 47 percent in clay in just 3 mo. Pachira brevipes suffered pathogen attack in both habitats that killed 90 percent of its establishing seedlings. Natural enemies thus strongly influence seedling recruitment of these two Pachira species in these forests and appear to have the largest impact within the seedlings' first few months.     

A new species of the genus Chaetopelma Ausserer, 1871 (Araneae: Theraphosidae) from Turkey

A new species of Chaetopelma Ausserer, 1871 is described from Hatay province, Turkey. Differences between the new species and related species are discussed. The characteristic features of this species are described and illustrated.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:99C21605-5308-4363-8420-02F6151B4457     

Comparison of effects of spatial autocorrelation on distribution predictions of four rare plant species in the Watarase wetland

We tested the effectiveness of distribution-prediction models for four rare herbaceous wetland species in the Watarase wetland, Japan, based on data obtained from aerial images. We used visible and near-infrared aerial images from three seasons, and elevations and vegetation heights derived from the images. Because spatial autocorrelation in species distribution data often biases the estimated effects of certain variables and reduces the prediction accuracy of distribution models, we compared the predictions of an intrinsic conditional autoregressive (CAR) model, which accounts for spatial autocorrelation, with those of a standard logistic regression model. The four study species had different distribution patterns: Ophioglossum namegatae and Impatiens ohwadae had aggregated distributions, whereas Galium tokyoense and Thalictrum simplex var. brevipes had scattered distributions. Predictions based on remote sensing images performed well for O. namegatae with the intrinsic CAR model and for I. ohwadae with both the logistic and CAR models; performance was poor for G. tokyoense and T. simplex var. brevipes with both models. Prediction accuracy improved by the CAR model in comparison to the logistic model most in O. namegatae and least in I. ohwadae. Impatiens ohwadae’s distribution was explained well by ground height. In contrast, the apparent improvement in the prediction for O. namegatae resulted from a substantial spatial random effect, suggesting the presence of determinants that could not be detected by remote sensing. The number of explanatory variables with large effects decreased in the intrinsic CAR model in three species possibly by avoiding spatial pseudoreplication, but not for T. simplex var. brevipes.     

Do additional sugar sources affect the degree of attendance of Dysmicoccus brevipes by the fire ant Solenopsis geminata?

Mutualistic interactions between ants and Hemiptera are mediated to a large extent by the amount and quality of sugar‐rich honeydew produced. Throughout the neotropics, the predaceous fire ant Solenopsis geminata (Fabricius) (Hymenoptera: Formicidae) is found in association with colonies of the pineapple mealybug, Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae), which they actively tend and protect from attack by natural enemies. In this study, we evaluate the effects of access to a sucrose solution on the mutualistic association between S. geminata and D. brevipes. Ten colonies of either species were established, with D. brevipes maintained on pumpkin, Cucurbita maxima Duchesne (Cucurbitaceae), in screen cages. Five of the S. geminata colonies were permitted access to vials with 20% sucrose solution and a pumpkin with 20 adult mealybugs. The remaining ant colonies were allowed access to mealybug‐infested pumpkins. Ant colonies with access to the sucrose solution attended mealybugs significantly less than those without additional sugar sources. Mealybug survival rates were similar under both treatments. Total body sugars and fructose were nearly twice as high in ants with access to honeydew and sucrose vs. those with access to honeydew and water. Fructose accumulated on the pumpkins over time in both treatments, suggesting that honeydew was not fully exploited by the ants. In conclusion, D. brevipes enjoy lower degrees of ant attendance when S. geminata have alternative sources of carbohydrates. We further discuss the significance of these findings for the conservation of predaceous ants and mealybug biological control.     

Dihaploids of Elymus from the interspecific crosses E. dolichatherus x E. tibeticus and E. brevipes x E. panormitanus

Summary Dihaploids (n=2x=14, SY) of two Elymus species, i.e., E. dolichatherus (Keng) Löve (2n=4x=28, SSYY) and E. brevipes (Keng) Löve (2n=4x=28, SSYY), were obtained from the interspecific hybrid combinations E. dolichatherus () x E. tibeticus (Meld.) G. Singh () and E. brevipes () x E. panormitanus (Parl.) Tzvelev (). The dihaploids were probably formed through selective elimination of male parental chromosomes in early embryo development. Meiotic chromosome behavior was studied in E. dolichatherus, E. brevipes, and their dihaploids. The two parental Elymus species had regular meioses with predominantly ring bivalent formation. A low frequency of homoeologous chromosome pairing was observed, with an average of 0.81 bivalents and 0.03 trivalents in the dihaploid of E. dolichatherus, and 0.26 bivalents in the dihaploid of E. brevipes. Up to two chromatid bridges accompanied by small fragments were present at anaphase I of the E. dolichatherus dihaploid. It is concluded from this study that: (i) both E. dolichatherus and E. brevipes are allotetraploid species; (ii) a low affinity exists between the S and Y genomes of the two Elymus species.     

Genetic isolation between two recently diverged populations of a symbiotic fungus

Fungi are an omnipresent and highly diverse group of organisms, making up a significant part of eukaryotic diversity. Little is currently known about the drivers of fungal population differentiation and subsequent divergence of species, particularly in symbiotic, mycorrhizal fungi. Here, we investigate the population structure and environmental adaptation in Suillus brevipes (Peck) Kuntze, a wind‐dispersed soil fungus that is symbiotic with pine trees. We assembled and annotated the reference genome for Su. brevipes and resequenced the whole genomes of 28 individuals from coastal and montane sites in California. We detected two clearly delineated coast and mountain populations with very low divergence. Genomic divergence was restricted to few regions, including a region of extreme divergence containing a gene encoding for a membrane Na⁺/H⁺ exchanger known for enhancing salt tolerance in plants and yeast. Our results are consistent with a very recent split between the montane and coastal Su. brevipes populations, with few small genomic regions under positive selection and a pattern of dispersal and/or establishment limitation. Furthermore, we identify a putatively adaptive gene that motivates further functional analyses to link genotypes and phenotypes and shed light on the genetic basis of adaptive traits.     

Cytogenetic studies of the intergeneric hybrids between Secale cereale and Elymus caninus,E. brevipes,and E. tsukushiensis (Triticeae: Poaceae)

Summary Integeneric hybridizations were carried out between Secale cereale L. (2n = 14, RR) and three Elymus species, namely, E. caninus (L.) L. (2n = 28, SSHH), E. brevipes (Keng) Löve (2n = 28, SSYY) and E. tsukushiensis Honda (2n = 42, SSHHYY). Chromosome pairing was studied at metaphase I in the parental species and the hybrids. Meiotic configurations of the hybrids were 20.74 1+0.14 II for E. caninus x S. cereale (SHR), 16.35 I+2.17 II+0.09 III for E. brevipes x S. cereale (SYR) and 25.84 I+1.10 II+0.02 III for E. tsukushiensis x S. cereale (SHYR), in addition to some secondary associations in the different hybrids. It is concluded from the study that (1) a certain, different homoeologous relationship exists among S, H and Y genomes in the investigated Elymus species; (2) low homoeology is present between genomes of Elymus (S or H or Y) and rye (R); (3) the Secale genome affects homoeologous chromosome pairing between different genomes in E. brevipes and E. tsukushiensis.     

Ants climb plants because they cannot swim: ant presence on flowers during the flood season reduces the frequency of floral visitors

1. Seasonal changes in environments may not only affect habitat connectivity but may also affect its use by species and their interactions. Thus, during the flood season, ants are forced to develop survival strategies such as vertical plant migration.
2. According to this, it has been hypothesized that the presence of ants may directly affect plant-pollinator interactions.
3. Thus, we asked the following questions: (i) Are floral visitors of Hyptis brevipes expelled due to ant presence on inflorescences during the flood period? (ii) Is the ant effect mediated by the abundance of ants foraging on inflorescences? And, (iii) Does flower abundance predict the abundance of floral visits and ants?
4. We experimentally sampled 59 H. brevipes plants with and without ants during the flooded season, and observed no differences in flower abundance between ant treatments.
5. The probability of detaining floral visitors on H. brevipes increased with ant abundance and exceeded 50% possible repellency, but the probability of visitor deterrence was not related to flower abundance. Furthermore, the abundance of flowers did not predict the number of ants on H. brevipes individuals or the frequency of floral visits.
6. Consequently, ant repelling effects are pronounced when there are more ants foraging on plants. However, the ant repelling effect can be mitigated when plants flourish all year-round and exhibit higher concentrations of flowers in the dry months. Additionally, the different sexual functions of plants may present specific responses due to the explosive pollination mechanism associated with ant effects.

     

A Bryophyte Flora of Hertfordshire

Abstract

A new species, Bruchia queenslandica, collected in tropical Australia, is described. It is similar to B. carolinae in spore features but differs in the smooth calyptra and in vegetative characters. It is compared with B. carolinae and B. brevipes     

Niche Partitioning of Feather Mites within a Seabird Host, Calonectris borealis

According to classic niche theory, species can coexist in heterogeneous environments by reducing interspecific competition via niche partitioning, e.g. trophic or spatial partitioning. However, support for the role of competition on niche partitioning remains controversial. Here, we tested for spatial and trophic partitioning in feather mites, a diverse and abundant group of arthropods. We focused on the two dominant mite species, Microspalax brevipes and Zachvatkinia ovata, inhabiting flight feathers of the Cory’s shearwater, Calonectris borealis. We performed mite counts across and within primary and tail feathers on free-living shearwaters breeding on an oceanic island (Gran Canaria, Canary Islands). We then investigated trophic relationships between the two mite species and the host using stable isotope analyses of carbon and nitrogen on mite tissues and potential host food sources. The distribution of the two mite species showed clear spatial segregation among feathers; M. brevipes showed high preference for the central wing primary feathers, whereas Z. ovata was restricted to the two outermost primaries. Morphological differences between M. brevipes and Z. ovata support an adaptive basis for the spatial segregation of the two mite species. However, the two mites overlap in some central primaries and statistical modeling showed that Z. ovata tends to outcompete M. brevipes. Isotopic analyses indicated similar isotopic values for the two mite species and a strong correlation in carbon signatures between mites inhabiting the same individual host suggesting that diet is mainly based on shared host-associated resources. Among the four candidate tissues examined (blood, feather remains, skin remains and preen gland oil), we conclude that the diet is most likely dominated by preen gland oil, while the contribution of exogenous material to mite diets is less marked. Our results indicate that ongoing competition for space and resources plays a central role in structuring feather mite communities. They also illustrate that symbiotic infracommunities are excellent model systems to study trophic ecology, and can improve our understanding of mechanisms of niche differentiation and species coexistence.     

Strong postmating reproductive isolation in Mimulus section Eunanus

Postmating reproductive isolation can help maintain species boundaries when premating barriers to reproduction are incomplete. The strength and identity of postmating reproductive barriers are highly variable among diverging species, leading to questions about their genetic basis and evolutionary drivers. These questions have been tackled in model systems but are less often addressed with broader phylogenetic resolution. In this study we analyse patterns of genetic divergence alongside direct measures of postmating reproductive barriers in an overlooked group of sympatric species within the model monkeyflower genus, Mimulus. Within this Mimulus brevipes species group, we find substantial divergence among species, including a cryptic genetic lineage. However, rampant gene discordance and ancient signals of introgression suggest a complex history of divergence. In addition, we find multiple strong postmating barriers, including postmating prezygotic isolation, hybrid seed inviability and hybrid male sterility. M. brevipes and M. fremontii have substantial but incomplete postmating isolation. For all other tested species pairs, we find essentially complete postmating isolation. Hybrid seed inviability appears linked to differences in seed size, providing a window into possible developmental mechanisms underlying this reproductive barrier. While geographic proximity and incomplete mating isolation may have allowed gene flow within this group in the distant past, strong postmating reproductive barriers today have likely played a key role in preventing ongoing introgression. By producing foundational information about reproductive isolation and genomic divergence in this understudied group, we add new diversity and phylogenetic resolution to our understanding of the mechanisms of plant speciation.     

A new Sparassis species from Spain described using morphological and molecular data

Sparassis miniensis, collected in Pinus pinaster forests in Galicia (northwest Iberian Peninsula) is described as a new species, based on morphological and molecular data. Sparassis miniensis is morphologically distinct from all other species in the genus Sparassis based on scattered flabellae, which are strongly laciniated, azonate, and arise from an orange to rose-purplish base. The sporadic presence of clamp connections is restricted to subhymenial hyphae. Molecular data from LSU-rDNA, ITS and partial gene coding RNA polymerase subunit II (rpb2) suggest a close relationship between the new species S. miniensis and S. brevipes, another European species producing large fruiting bodies but with entire flabellae and no clamp connections.     

An exceptionally preserved Jurassic skink suggests lizard diversification preceded fragmentation of Pangaea

The present distribution of lizards is usually explained as a result of relatively recent global events, i.e. faunal turnovers or exchanges within and between particular continents mostly connected with glaciations and land‐bridges. However, today's disjunct distribution of the North American Xantusiidae and African Cordyliformes (close relatives of skinks) does not fit generally accepted biogeographical patterns. A new, exquisitely preserved specimen of the Late Jurassic lizard Ardeosaurus brevipes from the Solnhofen area, Germany sheds some light on the problem. A posterior projection of its parietal is known only in the Dibamidae, Gekkota and Scincoidea, taxa representing first branches on the molecular tree of lizards. The projection of the parietal is proposed to be an apomorphy of the Squamata that was lost in the common ancestor of Lacertoidea and Toxicofera (snakes, anguimorphs and iguanians). This implies a basalmost position of A. brevipes on the Squamata tree. The location of the supratemporal such as in A. brevipes characterizes all the Scincoidea and some geckos, but most geckos lack osteoderms, which are common in Scincoidea. This makes A. brevipes the oldest known crown‐member of this lineage. Moreover, this indicates that the main groups of modern lizards were already present in the Jurassic. Ancestors of Cordyliformes migrated to Gondwana in the Late Jurassic together with dinosaurs, prior to the Cretaceous separation of this ancient continent.     

Encalypta brevipes and E. brevicolla: new records from North America,Iceland, Great Britain and Europe

Abstract

Encalypta brevipes Schljak. is reported in North America from north-western-most Oregon, United States; from Iceland; and in Europe from the Alps in southeastern France, and the High Tatra Mountains in Czechoslovakia. Encalypta brevicolla (B.S.G.) Bruch ex Aongstr. is reported from southernmost coastal Oregon, United States and east-central Scotland, Great Britain.     

A molecular investigation of the genus Ecklonia (Phaeophyceae,Laminariales) with special focus on the Southern Hemisphere

Brown algae of the order Laminariales, commonly referred to as kelps, are the largest and most productive primary producers in the coastal inshore environment. The genus Ecklonia (Lessoniaceae, Phaeophyceae) consists of seven species with four species in the Northern Hemisphere and three in the Southern Hemisphere. It was recently transferred to the family Lessoniaceae based on phylogenetic analyses of nuclear and chloroplastic markers, though the type of the genus was not included and its relationship with allied genera Eckloniopsis and Eisenia remained unresolved. The present study is the first to produce a phylogeny focussed on the genus Ecklonia. It included sequences from nuclear, mitochondrial, and chloroplastic DNA, for most of the distribution range of the three current Southern Hemisphere species (Ecklonia radiata, Ecklonia maxima, and a sample of a putative Ecklonia brevipes specimen), sequences for East Asiatic species (Ecklonia cava, Ecklonia kurome, and Ecklonia stolonifera), as well as the closely related genera Eckloniopsis and Eisenia. Results confirmed E. radiata and E. maxima as two distinct species in South Africa, E. radiata as a single species throughout the Southern Hemisphere (in South Africa, Australia, and New Zealand) and East Asiatic species as a distinct lineage from the Southern Hemisphere clade. Results further pointed out a close sister relationship between Eckloniopsis radicosa and two Eisenia species (including the type species: Eisenia arborea) to the genus Ecklonia suggesting that the genera Eckloniopsis and Eisenia are superfluous.