In vitro effects of copper nanoparticles on plant pathogens, beneficial microbes and crop plants

Copper-based chemicals are effectively used as antimicrobials in agriculture. However, with respect to its nanoparticulate form there has been limited number of studies. In this investigation, in vitro tests on effect of copper nanoparticles (CuNPs) against plant pathogenic fungi, oomycete, bacteria, beneficial microbes Trichoderma harzianum and Rhizobium spp., and wheat seeds were conducted. Integration of CuNPs with non-nano copper like copper oxychloride (CoC) at 50 mg/L concentration each recorded 76% growth inhibition of the oomycete Phytophthora cinnamomi in vitro compared to the control. CuNPs also showed synergistic inhibitory effect with CoC on mycelial growth and sporulation of A. alternata. Pseudomonas syringae was inhibited at 200 mg/L of CuNPs. CuNPs were not significantly biocidal against Rhizobium spp. and Trichoderma harzianum compared to CoC. Evaluation of the effect of CuNP on wheat revealed that rate of germination of wheat seeds was higher in presence of CuNPs and CoC compared to control. Germination vigor index, root length, shoot dry weight and seed metabolic efficiency of wheat were negatively affected. At low concentration, CuNPs promoted the growth of the plant pathogenic fungi Botrytis fabae, Fusarium oxysporum f.sp. ciceris, F.oxysporum f.sp. melonis, Alternaria alternate and P. syringae, and sporulation of T. harzianum. Synergistic effect of CuNPs and CoC in inhibiting P. cinnamomi offers a possibility of developing new fungicide formulation for better control of the oomycetes. Non-biocidal effect of CuNPs against beneficial microbes indicates its potential use in the agri-ecosystem

Flow injection determination of total catechins and procyanidins in white and red wines

An easily automatable flow-injection (FI) method for the determination of total catechins is reported. The method is based on the reaction of vanillin in acid medium to yield a coloured product with maximum absorption at 500 nm. After optimisation by the univariate and multivariate approaches as required, the linear range was established (between 10 and 90 mgL-1 and 10 and 250 mgL-1 for white and red wines, respectively). Then, the assessment of the proposed versus the reference method was studied in terms of repeatability (2.57 mgL-1), reproducibility (3.56 mgL-1) (no significant differences were found), detection and quantification limits (not far from those of the reference method and always sufficient for the determination of catechins in any type of wine), traceability (excellent correlation under all conditions) and sample throughput (23 samples h-1 for the proposed method versus 3 samples h-1 for the reference method)

Flow injection determination of readily assimilable nitrogen compounds during vinification

A flow injection method for the determination of readily assimilable nitrogen (r.a.n.), i.e. ammonium and aminated nitrogen, is reported. The difference in pH of the sample in the presence and absence of formaldehyde, which blocks the amino function, provides the value of r.a.n. by monitoring the changes in absorbance of bromothymol blue at 616 nm. The detection and quantification limits are 10 and 11.6 mg l-1, respectively; the reproducibility and repeatability are 3.94 mg l-1 and 1.35 mg l-1, respectively; and the sample throughput is 20 samples h-1. The method has been applied to the analysis of 120 samples of must and wine subjected to biological aging. The proposed method also provides good correlation with the reference method used in routine analysis, and it is faster and gives sufficient precision for wineries requirements

Differences in crenate broomrape parasitism dynamics on three legume crops using a thermal time model

Root parasitic weeds are a major limiting production factor in a number of crops, and control is difficult. Genetic resistance and chemical control lead the fight, but without unequivocal success. Models that help to describe and even predict the evolution of parasitism underground are a valuable tool for herbicide applications, and even could help in breeding programs. Legumes are heavily affected by Orobanche crenata (crenate broomrape) in the Mediterranean basin. This work presents a descriptive model based on thermal time and correlating growing degree days (GDD) with the different developmental stages of the parasite. The model was developed in three different legume crops (faba bean, grass pea and lentil) attacked by crenate broomrape. The developmental stages of the parasite strongly correlated with the GDD and differences were found depending on the host crop. [This Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permission.

Uso de nanodiscos de anfotericina B (AMB-NDs) para el tratamiento de enfermedades fúngicas en plantas

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

Macro- and Microscopic Characterization of Components of Resistance against Puccinia striiformis f. sp. tritici in a Collection of Spanish Bread Wheat Cultivars

Yellow (stripe) rust, caused by the biotrophic fungus Puccinia striiformis f. sp. tritici (Pst), stands as the most serious wheat disease worldwide, affecting approximately 88% of world wheat production. Even though yellow rust generally develops in cool humid weather conditions, the expansion of new races adapted to warmer climates threatens zones where severe P. striiformis epidemics were infrequent, such as Andalusian wheat cropping areas. In order to characterize yellow rust resistance mechanisms in Spanish germplasm, our study evaluated 19 Spanish bread wheat cultivars against P. striiformis under controlled conditions for percentage of disease severity (DS) and infection type (IT). From this visual evaluation, 74% of evaluated cultivars showed resistant responses against P. striiformis infection with only five cultivars considered susceptible. Subsequently, macroscopic and microscopic components of resistance were identified through image analysis and histological studies, respectively, in six selected cultivars. Macroscopic parameters such as total pustule area and total affected area (%), together with microscopic parameters such as early-aborted and established microcolonies regarding plant cell death responses (%), and microcolony length (µm), were identified as capable of differentiating cultivars quantitatively. Thus, these parameters could be used as a basis for screening resistant responses in future breeding programs, complementary to physiology, genetic and biochemical studies of plant-Pst interaction. Finally, our study seems to be the first macroscopic and microscopic characterization of P. striiformis infection in a collection of Spanish bread wheat cultivars in controlled conditions

Communal Decay: Narratological and Ideological Analysis of H.P. Lovecraft's Fiction

La presente tesis doctoral se centra en el análisis de la obra narrativa del escritor norteamericano H.P. Lovecraft (1890-1937). Lovecraft escribió principalmente relatos cortos, la gran mayoría enmarcados en el género fantástico en su concepción más amplia, con derivaciones hacia el relato gótico, la ciencia ficción o las historias oníricas. El propósito del estudio es, empleando un marco teórico basado en las propuestas del filósofo Slavoj Žižek, interpretar las posibles constantes ideológicas que se filtran en la narrativa del escritor. La propuesta de Žižek parte de la separación de los conceptos lacanianos de realidad y Real. La realidad, aquello que el ser humano es capaz de distinguir, aprehender y asimilar, comprende el mundo que nos rodea. Lo Real lacaniano, por el contrario, es aquello que se encuentra más allá de la realidad, que es incomprensible, demasiado terrible para ser asimilado por el género humano. De acuerdo con la propuesta del Žižek, lo Real se divide en tres subcategorías fundamentales: lo Real simbólico, lo Real imaginario y lo Real real. Lo Real simbólico se corresponde en última instancia con nuestra realidad, a la que le damos forma gracias a concepciones de carácter religioso, ideológico, comunitario, etc. Lo Real imaginario aparece cuando hay alguna falla en el nivel simbólico, que hace que los esquemas de realidad se tambaleen. Lo Real real, por último, se corresponde con lo Real lacaniano, con la Cosa incomprensible e indescriptible. La tríada de lo Real de Žižek proviene de una propuesta religiosa, en la que el filósofo compara cada elemento de la Santísima Trinidad con uno de los tres tipos de Real que formula. Así, lo Real real equivale a Dios, lo Real imaginario se corresponde con el..