A geostatistical model to describe root vitality and ectomycorrhization in Norway spruce

Abstract

The spatial distribution of vital root tips and ectomycorrhizal (ECM) communities in forest soils is characterized by patchiness at a microscale level, mostly related to the distribution patterns of biotic and abiotic factors. A geostatistical model was applied to verify if spatial analyses could be useful in identifying an appropriate sampling method to study root tip vitality, ectomycorrhization and the ECM community. Root samples were collected from two high mountain Norway spruce forests (Trentino province, Italy) following a geometrical design. Laboratory microscopic and geostatistical ordinary kriging analyses were used to map tip vitality and ectomycorrhization degree, ECM richness and distribution grouped in “exploration types” (amount of emanating hyphae or presence and differentiation of rhizomorphs). Spatial gradients of the examined features existed at plant level, associated to the up-downslope direction (root tip vitality and ectomycorrhization, ECM richness) and distance from the stem base (ECM exploration types). The effectiveness of the geostatistical model used demonstrates that a geometrical sampling design, associated to spatial mapping techniques, can be useful in research where the tree, and not the forest, is the subject (mycological and phytopathological studies).     

Notes on black elytron species of Pyrrhalta Joannis and the description of a new species from China (Coleoptera,Chrysomelidae, Galerucinae)

Thirteen species of Pyrrhalta Joannis, 1865 with black elytron are reviewed. A key to species, photographs of aedeagus and habitus are provided. Pyrrhalta qianana sp. n. is described from Guizhou, China. Pyrrhalta martensi Medvedev & Sprecher-Uebersax, 1999 is newly recorded from China (Tibet).     

In vitro and in vivo antimicrobial efficacy of essential oils and individual compounds against Phytophthora parasitica var. nicotianae

Aim

To evaluate the antimicrobial effects of essential oils (EOs) from cassia, basil, geranium, lemongrass, cumin and thyme, as well as their major components, against Phytophthora parasitica var. nicotianae; to investigate morphological changes in hyphae and sporangia in response to treatment with cinnamaldehyde; and to further evaluate potential biocontrol capacities against tobacco black shank under greenhouse conditions.

Methods and Results

The results revealed that the extent of mycelial growth inhibition was primarily dependent on the composition and concentration of the EOs and the structure of individual compounds. Cinnamaldehyde had a significantly higher inhibitory effect on mycelial growth, formation of sporangia, and production and germination of zoospores in P. parasitica var. nicotianae in vitro, achieving complete inhibition of these phenotypes at 72, 36, 36 and 18 mg l^?1, respectively. Scanning electron microscopic observations revealed that cinnamaldehyde can cause considerable morphological degenerations of hyphae and sporangia such as cytoplasmic coagulation, shrivelled mycelia and sporangia aggregates and swelling and lysis of mycelia and sporangia walls. In vivo assays with cinnamaldehyde demonstrated that this compound afforded protective effect against tobacco black shank under greenhouse conditions in susceptible tobacco plants.

Conclusions

The results of in vitro and in vivo bioassays, together with SEM imaging of the microstructure of P. parasitica var. nicotianae supported the possibility of using cinnamaldehyde as a potent natural biofungicide in the greenhouse.

Significance and Impact of the Study

This study provides a theoretical basis for the potential use of cinnamaldehyde as commercial agents or lead compounds that can be exploited as commercial biofungicides in the protection of tobacco plants from P. parasitica var. nicotianae infection.     

Nutritional composition of black soldier fly larvae feeding on agro-industrial by-products

Black soldier fly (BSF) larvae, Hermetia illucens L. (Diptera: Stratiomyidae), bio-convert organic side streams into high-quality biomass, the composition of which largely depends on the side stream used. In the present study, BSF larvae were reared on feed substrates composed of dried brewers’ spent grains, each supplemented with either water, waste brewer’s yeast, or a mixture of waste brewer’s yeast and cane molasses to obtain 12 different substrates: barley/water, barley/yeast, barley/yeast/molasses, malted barley/water, malted barley/yeast, malted barley/yeast/molasses, malted corn/water, malted corn/yeast, malted corn/yeast/molasses, sorghum-barley/water, sorghum-barley/yeast, and sorghum-barley/yeast/molasses. The crude protein, fat, ash, and mineral contents of the BSF larvae fed each feed substrate were quantified by chemical analyses. The effect of substrate, supplementation, and their interaction on crude protein, fat, and ash contents of BSF larval body composition was significant. Calcium, phosphorus, and potassium were the most abundant macrominerals in the larvae and their concentrations differed significantly among substrates. These findings provide important information to support the use of BSF larval meal as potential new source of nutrient-rich and sustainable animal feed ingredients to substitute expensive and scarce protein sources such as fishmeal and soya bean meal.     

Geometric morphometrics as a tool for interpreting evolutionary transitions in the black fly wing (Diptera: Simuliidae)

A geometric morphometric analysis was conducted on wing‐vein landmarks on exemplar species of the family Simuliidae of the following genera: Parasimulium, Gymnopais, Twinnia, Helodon, Prosimulium, Greniera, Stegopterna, Tlalocomyia, Cnephia, Ectemnia, Metacnephia, Austrosimulium, and Simulium. Generalized least squares superimposition was performed on landmarks, followed by a principal component analysis on resulting Procrustes distances. Patterns of shape change along the principal component axes were visualized using the thin‐plate spline. The analysis revealed wing shape diversity through (1) the insertion points of the subcosta and R₁, resulting in the terminus of the costa exhibiting a trend towards a more apical position on the wing, and (2) the insertion point of the humeral cross vein, resulting in the anterior branch of the media exhibiting a trend toward a more basal position on the wing. Canonical variates analysis of Procrustes distances successfully assigned all exemplar species into their a priori taxonomic groupings. The diversity in wing shape reveals a trend towards decreased length of basal radial cell and increased costalization of anterior wing veins in the evolutionary transition from plesiomorphic prosimuliines to more derived simuliines. The functional significance of these evolutionary transitions is discussed. © 2013 The Linnean Society of London     

Ethnic identity on display: West Indian youth and the creation of ethnic boundaries in high school

The black immigrant population in New York City has grown exponentially since 1990, such that West Indians now compose the majority of the black population in several neighbourhoods. This article examines how this ethnic density manifests among youth in high school, and how it has influenced ethnic identity formation among second-generation West Indians. My findings are based on twenty-four interviews and eight months of participant observation in two Brooklyn high schools from 2003 to 2004. The results show that in both schools, Caribbean island identities have become a ‘cool’ commodity within peer groups. Further, although it was important to express pride in one's island identity, these young people often blurred their national origin boundaries by drawing on Jamaican popular culture as way of projecting a unified ‘West Indian identity’. The research also uncovers evidence of a de-stigmatization of Haitianness as a way to incorporate them as cultural insiders into the larger Caribbean collective.     

Why aren't there more black football managers?

Abstract

The number of black and minority ethnic (BME) managers in English professional association football, or soccer, has been stable for nearly ten years: there are usually between two and four (out of a possible ninety two). Yet black players regularly make up more than a quarter of professional club squads. The reasons for this apparent under-representation are explored among 1,000 football fans, including players and ex-players, both white and BME. Opinions were solicited via an online research platform http://www.topfan.co.uk, designed and executed by the authors. The findings indicate 56 per cent of respondents believe racism operates at the executive levels of football, i.e. the boardroom. While some accuse club owners and directors of deliberate discrimination, most suspect a form of unwitting or institutional racism in which assumptions about black people's capacities are not analysed and challenged and so continue to circulate. Among the possible remedies to this is the American National Football League's Rooney Rule, which mandates BME candidates’ inclusion on shortlists for senior coaching positions. A third of participants in the research approved of this type of initiative. While black managers are scarce when compared to the number of black players in professional football, their presence is actually an accurate reflection of their number in the total British population. So is the dearth of black managers an under-representation?     

Chocolate cities: A brief note from a race and capitalism perspective

Marcus Hunter and Zandria Robinson have provided us with an innovative methodology for analysing “maps” of African Americans’ lived political, social and cultural experiences past and present. Their powerful innovation is creating maps of the black experience based on black people’s lived experience. They argue that carefully tracing spatially blacks’ political, social and cultural patterns over time leads one to the conclusion that the shared experiences of blacks throughout the polity (and indeed throughout the Diaspora) have far more in common than not. I argue that we can better understand not only the maps that black people have created, but also chocolate cities themselves by using an analytical framework that integrates the analysis of the lived experience of black people with a structural analysis that interrogates the articulation of white supremacy, capitalism and patriarchy. This framework is related to the developing research into racial capitalism that is now being conducted globally.