Fitness cost but no selection for virulence in Meloidogyne incognita after two consecutive crops of eggplant grafted onto Solanum torvum

The eggplant Solanum melongena cv. Cristal, either ungrafted or grafted onto the Solanum torvum rootstock cv. Brutus, was cultivated for two consecutive years in the same plots in a plastic greenhouse to assess the level of resistance to Meloidogyne incognita and crop yield. At the end of the second crop, the putative selection for virulence of the nematode subpopulations coming from infected ungrafted and grafted eggplant was assessed in the eggplant and in S. torvum in a pot experiment. Nematode population densities at transplantation in 2017 ranged from 2 to 378 per 100 cm³ of soil and did not differ between ungrafted and grafted eggplant. At the end of each crop, a higher galling index and number of nematodes in soil and in roots was registered in ungrafted compared to grafted eggplant. The grafted eggplant was categorized as resistant in 2017 and as highly resistant in 2018. Eggplant yield did not differ irrespective of grafting in 2017 after being cultivated for 135 days, but it differed after 251 days of cultivation in 2018. In the pot experiment, S. torvum was categorized as resistant to both M. incognita subpopulations. However, the M. incognita subpopulation obtained from roots of S. torvum produced 49.4% fewer egg masses and 56% fewer eggs per plant in the eggplant than the nematode subpopulation obtained from roots of the eggplant cv. Cristal. The results of this study revealed that the infective and reproductive fitness of the nematode decreased without having been selected for virulence.     

Host suitability of Solanum torvum cultivars to Meloidogyne incognita and M. javanica and population dynamics

Several experiments were carried out to assess the performance of commercial Solanum torvum cultivars against the root knot nematodes Meloidogyne incognita and M. javanica in Spain. The response of S. torvum rootstock cultivars Brutus, Espina, Salutamu and Torpedo against M. incognita and Mi-1.2 (a)virulent M. javanica isolates was determined in pot experiments, and of ‘Brutus’ to an N-virulent isolate of M. incognita, compared with that of the eggplant S. melongena ‘Cristal’. The relationship between the initial and final population densities of M. javanica on ungrafted and grafted ‘Cristal’ onto the S. torvum ‘Brutus’ was assessed, together with the effect on dry shoot biomass. Finally, the population growth rate and the resistance level of the four S. torvum cultivars against M. incognita was assessed under plastic greenhouse conditions in two cropping seasons. All S. torvum rootstocks responded as resistant to the M. incognita isolates and from highly resistant to susceptible against M. javanica isolates. The maximum multiplication rates of M. javanica on the ungrafted or grafted eggplant were 270 and 49, respectively, and the equilibrium densities were 1318 and 2056 eggs and J2 per 100 cm³ soil, respectively. The tolerance of the ungrafted eggplant was 10.9 J2 per 100 cm³ soil, and the minimum relative dry shoot biomass was 0.76. The population growth rate of M. incognita on eggplant cv. Cristal differed from that of the S. torvum cultivars in both cropping seasons. These results suggest that S. torvum is a valuable rootstock for managing the two Meloidogyne species irrespective of the (a)virulence status.     

Integrating supply and demand in ecosystem service bundles characterization across Mediterranean transformed landscapes

Context

Humans continually transform landscapes, affecting the ecosystem services (ES) they provide. Thus, the spatial relationships among services vary across landscapes. Managers and decision makers have access to a variety of tools for mapping landscapes and analyzing their capacity to provide multiple ES.

Objectives

This paper characterizes and maps ES bundles across transformed landscapes in southeast Spain incorporating both the ecological and social perspectives. Our specific goals were to: (1) quantify ES biophysical supply, (2) identify public awareness, (3) map ES bundles, and (4) characterize types of ES bundles based on their social-ecological dimensions.

Methods

Biophysical models and face-to-face social surveys were used to quantify and map ES bundles and explore the public awareness in a highly transformed Mediterranean region. Then, we classified ES bundles into four types using a matrix crossing the degree of biophysical ES supply and the degree of social awareness.

Results

Results mapped seven ES bundles types representing diverse social-ecological dynamics. ES bundles mapped at the municipality level showed mismatches between their biophysical provision and the public awareness, which has important implications for operationalizing the bundles concept for landscape planning and management. ES bundles characterization identified four types of bundles scenarios.

Conclusions

We propose an ES bundles classification that incorporates both their social and ecological dimensions. Our findings can be used by land managers to identify areas in which ES are declining as well as priority areas for maximizing ES provision and can help to identify conflicts associated with new management and planning practices.

     

2-Vinyl-4H-1,3-Dithiin,a Bioavailable Compound from Garlic,Inhibits Vascular Smooth Muscle Cells Proliferation and Migration by Reducing Oxidative Stress

Plant Foods for Human Nutrition - Organosulfur compounds (OSCs) of garlic have various health benefits including anti-hypertensive effect. It has been described that volatile OSCs uptake occurs...     

Evidence of soil-located competition as the cause of the reduction of sunflower verticillium wilt by entomopathogenic fungi

The increasing limitation of agrochemicals for disease control is a major challenge for European agriculture and a spur to developing environmentally friendly approaches such as biological control. Entomopathogenic fungi, which have been used in the control of insect pests for a long time, also have other uses, such as being antagonists of fungi, including plant pathogens. We determined the in vitro effect of three strains of Metarhizium brunneum and two of Beauveria bassiana against Verticillium dahliae and Cadophora helianthi, causal agents of sunflower wilts. Both M. brunneum and B. bassiana were able to inhibit the mycelial growth of the sunflower pathogens and, according to the dual culture and microscopy results, two types of antagonism were observed as being dependent on the strain: competition and/or antibiosis. Greenhouse experiments showed that, after soil treatments with entomopathogens and plant inoculation by root immersion in conidial suspensions of V. dahliae, the entomopathogens were able to efficiently persist in the soil, and three of the four strains even significantly reduced the severity of symptoms in sunflowers. Interestingly, molecular analysis showed that all the strains were able to establish themselves as endophytes in sunflowers in the absence of V. dahliae. When the plants were inoculated with V. dahliae, we detected the pathogen, but not the entomopathogen, in the sunflowers by molecular methods. The results of this work suggest that the protection conferred by M. brunneum and B. bassiana against verticillium wilt might not be plant-located, but is probably the consequence of their competition with V. dahliae in the soil.     

The Diversity,Metabolomics Profiling,and the Pharmacological Potential of Actinomycetes Isolated from the Estremadura Spur Pockmarks (Portugal)

The Estremadura Spur pockmarks are a unique and unexplored ecosystem located in the North Atlantic, off the coast of Portugal. A total of 85 marine-derived actinomycetes were isolated and cultured from sediments collected from this ecosystem at a depth of 200 to 350 m. Nine genera, Streptomyces, Micromonospora, Saccharopolyspora, Actinomadura, Actinopolymorpha, Nocardiopsis, Saccharomonospora, Stackebrandtia, and Verrucosispora were identified by 16S rRNA gene sequencing analyses, from which the first two were the most predominant. Non-targeted LC-MS/MS, in combination with molecular networking, revealed high metabolite diversity, including several known metabolites, such as surugamide, antimycin, etamycin, physostigmine, desferrioxamine, ikarugamycin, piericidine, and rakicidin derivatives, as well as numerous unidentified metabolites. Taxonomy was the strongest parameter influencing the metabolite production, highlighting the different biosynthetic potentials of phylogenetically related actinomycetes; the majority of the chemical classes can be used as chemotaxonomic markers, as the metabolite distribution was mostly genera-specific. The EtOAc extracts of the actinomycete isolates demonstrated antimicrobial and antioxidant activity. Altogether, this study demonstrates that the Estremadura Spur is a source of actinomycetes with potential applications for biotechnology. It highlights the importance of investigating actinomycetes from unique ecosystems, such as pockmarks, as the metabolite production reflects their adaptation to this habitat.     

Serological evidence of Anaplasma spp., Borrelia burgdorferi and Ehrlichia canis in dogs from the Republic of Korea by rapid diagnostic test kits

BackgroundEmergent and re-emergent canine tick-borne infections are attracting increasing attention worldwide. The rise in pet ownership and the close relationship between dogs and their owners are the most concerning factors because dogs may act as competent reservoirs for human tick-transmitted infectious agents.ObjectivesThis study contributes to the epidemiological surveillance of canine tick-transmitted infections with zoonotic risk in the Republic of Korea (ROK) by investigating the seroprevalence of the pathogens, Anaplasma spp., Borrelia burgdorferi, and Ehrlichia canis.MethodsFour hundred and thirty whole blood samples from domestic dogs were collected in seven metropolitan cities and nine provinces in the ROK and tested using SensPERT Ab test kits (VetAll Laboratories®) to detect seroreactive animals.ResultsThe seroprevalence rates identified were 9.8% (42/430) for Anaplasma spp., 2.8% (12/430) for B. burgdorferi, and 1.4% (6/430) for E. canis. The risk factors evaluated in this study that could be associated with the development of a humoral immune response, such as sex, age, and history of tick exposure, were similar. There was only one exception for dogs seroreactive to Anaplasma spp., where the risk factor “tick exposure” was statistically significant (p = 0.047).ConclusionsThis serological survey exhibited the widespread presence of Anaplasma spp., B. burgdorferi, and E. canis throughout the ROK. Hence, dogs may play a key role as the sentinel animals of multiple zoonotic infectious agents in the country.     

A kinetic study of p-cresol oxidation by quince fruit polyphenol oxidase

The monophenolase activity of quince pulp polyphenol oxidase was characterized by extracting samples using a combination of a two-phase partition step in Triton X-114, followed by a PEG 8000/phosphate partition step, and a final ammonium sulfate fractionation between 30 and 75%. The purification method avoids the loss of cresolase activity described in another quince pulp polyphenol oxidase. The activity was characterized by a lag period, whose duration depended on the substrate concentration, the pH, and the presence of catalytic amounts of o-diphenol. By increasing the concentration of o-diphenols, it was possible to evaluate the enzyme activation constant, K(act), which showed a value of 4.5 microM for 4-methylcatechol. A general kinetic mechanism for this enzyme is used to explain the loss of activity that normally occurs during quince pulp polyphenol oxidase purification.     

Preliminary chemometric study on the use of honey as an environmental marker in Galicia (northwestern Spain)

Thirteen metal elements were determined in 40 honey samples from Galicia with different environmental origins: rural, urban, and industrial areas. The data set of the honey metallic profiles was studied with a double purpose: first, to make a preliminary evaluation of honey as an environmental indicator in Galicia with the aim of monitoring pollution and, second, to compare the different capabilities of diverse pattern recognition prediction procedures for modeling the environmental surrounding of the hive. A certain level of similarity for urban and industrial samples was obtained using principal component analysis and cluster analysis, whereas significant differences for urban and industrial honeys were found in relation to rural honey samples. Different classification rules to associate metal content of honeys with their environmental surrounding were obtained by chemometric pattern recognition procedures. In general, the classification methods developed by neural networks provided better results than the traditional pattern recognition procedures. The metal profiles of honey seem to provide sufficient information to enable categorization criteria for classifying samples according to their environmental surrounding. Thus, honey could be a potential pollution indicator for the Galician area.     

Effect of PPG-PEG-PPG on the Tocopherol-Controlled Release from Films Intended for Food-Packaging Applications

The feasibility of novel controlled release systems for the delivery of active substances from films intended for food packaging was investigated. Because polyolefins are used highly for food-packaging applications, the reported high retention degree of antioxidants has limited their use for active packaging. Thus, in this study, PP films modified with different chain extenders have been developed to favor and control the release rates of the low molecular weight antioxidant tocopherol. The use of different chain extenders as polymer modifiers (PE-PEG M(w), 575; and PPG-PEG-PPG M(w), 2000) has caused significant changes in tocopherol-specific release properties. High-performance liquid chromatography coupled to PDA-FL and PDA-MS was used to test tocopherol and chain extender migration, respectively. The release of tocopherol from the prepared films with two chain extenders into two food simulants was studied. Different temperatures and storage times were also tested. Varying the structural features of the films with the incorporation of different levels of PPG-PEG-PPG, the release of tocopherol (food-packaging additive) into different ethanolic simulants could be clearly controlled. The effect of the temperature and storage time on the release of the antioxidant has been outstanding as their values increased. The migration of the chain extender, also tested, was well below the limits set by European legislation.