scholarly journals Population density of Trichoderma fungi in natural environments and agrosystems of a Cerrado area

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
João Batista Tavares da Silva ◽  
Eder Marques ◽  
José Eustáquio Menezes ◽  
Joseane Padilha da Silva ◽  
Sueli Corrêa Marques de Mello
Keyword(s):  
Population Density ◽  
Farming Systems ◽  
Federal District ◽  
Native Vegetation ◽  
Natural Environments ◽  
Growth Promoters ◽  
Natural Ecosystems ◽  
Serial Sample ◽  
Decomposition Of Organic Matter ◽  
Trichoderma Fungi

Abstract: Soil microorganisms present a great diversity, involving taxonomically distinct groups that play a role in the decomposition of organic matter, nutrient cycling, soil aggregation, among others. In this diversity, the fungi of the genus Trichoderma have been successful plant pathogen biocontrol agents, as plant growth promoters and as inducers of plant resistance to diseases. In addition, they are important in the sustainability of natural ecosystems. Aiming to verify the population density of Trichoderma fungi in natural environments and agroecosystems, in Cerrado area, samples of soils and roots from native vegetation and agroecological production system were collected in the Federal District, Brazil. The collection points were randomly selected, and each soil or root sample was individually wrapped. The soil adhered to the roots was removed for evaluations. Serial sample dilutions and number of Colony Forming Units (CFUs) of Trichoderma isolates were performed. The results showed that the number of CFU varied depending on the plant and location evaluated. The replacement of native vegetation by organic farming systems did not result in a significant reduction in this number.

scholarly journals Natural variation in social conditions affects male mate choosiness in the amphipod Gammarus roeselii

2021 ◽  
Author(s):  
Konrad Lipkowski ◽  
Sophie Steigerwald ◽  
Lisa M Schulte ◽  
Carolin Sommer-Trembo ◽  
Jonas Jourdan
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Natural Variation ◽  
Natural Populations ◽  
Social Background ◽  
Social Conditions ◽  
Background Information ◽  
Male Mating ◽  
Natural Environments ◽  
Male Mate

Abstract The extent of male mate choosiness is driven by a trade-off between various environmental factors associated with the costs of mate acquisition, quality assessment and opportunity costs. Our knowledge about natural variation in male mate choosiness across different populations of the same species, however, remains limited. In this study, we compared male mate choosiness across 10 natural populations of the freshwater amphipod Gammarus roeselii (Gervais 1835), a species with overall high male mating investments, and evaluated the relative influence of population density and sex ratio (both affecting mate availability) on male mate choosiness. We investigated amplexus establishment after separating mating pairs and presenting focal males with a novel, size-matched female from the same population. Our analysis revealed considerable effects of sex ratio and (to a lesser extent) population density on time until amplexus establishment (choosiness). Male amphipods are able to perceive variable social conditions (e.g., sex ratio) and modify their mating strategy accordingly: We found choosiness to be reduced in increasingly male-biased populations, whereas selectivity increases when sex ratio becomes female biased. With this, our study expands our limited knowledge on natural variations in male mate choosiness and illustrates the importance of sex ratio (i.e., level of competition) for male mating decisions in natural environments. Accounting for variation in sex ratios, therefore, allows envisioning a distinctive variation of choosiness in natural populations and highlights the importance of considering social background information in future behavioral studies.

scholarly journals Trichoderma Strains and Metabolites Selectively Increase the Production of Volatile Organic Compounds (VOCs) in Olive Trees

Metabolites ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 213
Author(s):  
Irene Dini ◽  
Roberta Marra ◽  
Pierpaolo Cavallo ◽  
Angela Pironti ◽  
Immacolata Sepe ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Gas Chromatography Mass Spectrometry ◽  
Lipid Signaling ◽  
Plant Interactions ◽  
Growth Promoters ◽  
Volatile Organic ◽  
Trichoderma Fungi ◽  
Olive Trees ◽  
Plant Plant

Plants emit volatile organic compounds (VOCs) that induce metabolomic, transcriptomic, and behavioral reactions in receiver organisms, including insect pollinators and herbivores. VOCs’ composition and concentration may influence plant-insect or plant-plant interactions and affect soil microbes that may interfere in plant-plant communication. Many Trichoderma fungi act as biocontrol agents of phytopathogens and plant growth promoters. Moreover, they can stimulate plant defense mechanisms against insect pests. This study evaluated VOCs’ emission by olive trees (Olea europaea L.) when selected Trichoderma fungi or metabolites were used as soil treatments. Trichoderma harzianum strains M10, T22, and TH1, T. asperellum strain KV906, T. virens strain GV41, and their secondary metabolites harzianic acid (HA), and 6-pentyl-α-pyrone (6PP) were applied to olive trees. Charcoal cartridges were employed to adsorb olive VOCs, and gas chromatography mass spectrometry (GC-MS) analysis allowed their identification and quantification. A total of 45 volatile compounds were detected, and among these, twenty-five represented environmental pollutants and nineteen compounds were related to olive plant emission. Trichoderma strains and metabolites differentially enhanced VOCs production, affecting three biosynthetic pathways: methylerythritol 1-phosphate (MEP), lipid-signaling, and shikimate pathways. Multivariate analysis models showed a characteristic fingerprint of each plant-fungus/metabolite relationship, reflecting a different emission of VOCs by the treated plants. Specifically, strain M10 and the metabolites 6PP and HA enhanced the monoterpene syntheses by controlling the MEP pathway. Strains GV41, KV906, and the metabolite HA stimulated the hydrocarbon aldehyde formation (nonanal) by regulating the lipid-signaling pathway. Finally, Trichoderma strains GV41, M10, T22, TH1, and the metabolites HA and 6PP improve aromatic syntheses at different steps of the shikimate pathway.

Tuberculosis epidemic situation in the Khabarovsk Krai: status and trends

2021 ◽  
Vol 87 (1) ◽  
pp. 17-24
Author(s):  
K.P. Topalov ◽  
◽  
O.L. Karpenko ◽  
E.G. Kovalyova ◽  
◽  
...  
Keyword(s):  
Population Density ◽  
Federal District ◽  
Khabarovsk Krai ◽  
Its Regions ◽  
Status And Trends ◽  
The Russian Federation ◽  
Far Eastern ◽  
Statistical Indicators ◽  
Tuberculosis Care

The article presents an overview of the data of statistical observation of the Khabarovsk Krai, the Russian Federation and the Far Eastern Federal District (Okrug) on tuberculosis; their significance for assessing the epidemic situation and the quality of anti-tuberculosis care in these territories in 2002–2019 is studied. The dynamics of statistical indicators for 18 years is given using the methodology for calculating rank values. The dependence of the incidence of tuberculosis on the population density in the constituent entities of the country, the Far Eastern Federal District and its regions has been determined

scholarly journals Using virtual reality to estimate aesthetic values of coral reefs

2018 ◽  
Vol 5 (4) ◽  
pp. 172226 ◽  
Author(s):  
Julie Vercelloni ◽  
Sam Clifford ◽  
M. Julian Caley ◽  
Alan R. Pearse ◽  
Ross Brown ◽  
...  
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Structural Complexity ◽  
Natural Environments ◽  
Natural Ecosystems ◽  
Aesthetic Value ◽  
Natural Systems ◽  
Holistic Conservation ◽  
Past Experiences ◽  
Aesthetic Values

Aesthetic value, or beauty, is important to the relationship between humans and natural environments and is, therefore, a fundamental socio-economic attribute of conservation alongside other ecosystem services. However, beauty is difficult to quantify and is not estimated well using traditional approaches to monitoring coral-reef aesthetics. To improve the estimation of ecosystem aesthetic values, we developed and implemented a novel framework used to quantify features of coral-reef aesthetics based on people's perceptions of beauty. Three observer groups with different experience to reef environments (Marine Scientist, Experienced Diver and Citizen) were virtually immersed in Australian's Great Barrier Reef (GBR) using 360° images. Perceptions of beauty and observations were used to assess the importance of eight potential attributes of reef-aesthetic value. Among these, heterogeneity, defined by structural complexity and colour diversity, was positively associated with coral-reef-aesthetic values. There were no group-level differences in the way the observer groups perceived reef aesthetics suggesting that past experiences with coral reefs do not necessarily influence the perception of beauty by the observer. The framework developed here provides a generic tool to help identify indicators of aesthetic value applicable to a wide variety of natural systems. The ability to estimate aesthetic values robustly adds an important dimension to the holistic conservation of the GBR, coral reefs worldwide and other natural ecosystems.

Lunar Cycle Influences Production of Tilapia (Oreochromis spp) Eggs in an Intensive Outdoor Production System in the Tropics

2022 ◽  
pp. 074873042110694
Author(s):  
Miguel F. Perea ◽  
Daniel A. Perdomo ◽  
Zenaida A. Corredor ◽  
Mario González ◽  
Hugo Hernandez-Fonseca ◽  
...  
Keyword(s):  
Production System ◽  
Full Moon ◽  
Farming Systems ◽  
Fish Farming ◽  
Reproductive Activity ◽  
Lunar Cycle ◽  
Natural Environments ◽  
The Moon ◽  
Commercial Fish ◽  
The Tropics

A robust body of evidence has demonstrated that the lunar cycle plays an important role in the reproduction of fish living in natural environments. However, little is known about the influence of the moon on tilapia reproductive activity in intensive fish farming systems. This study aims to evaluate the influence of the lunar cycle on the reproductive performance of tilapias in an intensive outdoor tropical production system in Latin America. Records of two tilapia strains (Nile tilapia [ Oreochromis niloticus; n = 75] and Red tilapia [ Oreochromis spp.; n = 1335]) reared in concrete tanks in a commercial fish farm were analyzed. Over a 3-year period, 60,136 captures were made in intervals of 12 to 14 days and 6,600 females were manually spawned. The number of females spawned and the volume of eggs collected from each tank ( n = 9) were recorded. Data was analyzed by the general linear model and means were compared by least squares means method. A very slight or no variation was observed when the lunar cycle was split into two halves (crescent and waning). The proportions of females spawned and the volume of eggs per spawned female and per female in the tank varied considerably across the eight periods of the lunar cycle, with greater values in the waning than in the crescent phase. A significantly greater proportion of tilapia spawned and yielded more eggs around the full moon than around the new moon and remaining days of the lunar cycle. The moon cycle affected the reproductive activity of tilapia, which were more reproductively active around the full moon and most of the waning phase.

scholarly journals Advancing Genome-Resolved Metagenomics beyond the Shotgun

mSystems ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Rex R. Malmstrom ◽  
Emiley A. Eloe-Fadrosh
Keyword(s):  
Single Molecule ◽  
Cell Sorting ◽  
Stable Isotope Probing ◽  
Natural Environments ◽  
Natural Ecosystems ◽  
Shotgun Metagenomics ◽  
Short Read ◽  
Future Developments ◽  
Long Read ◽  
Shed Light

ABSTRACT Exploration of environmental microbiomes has shed light on the ecological and evolutionary principles at play in natural ecosystems and has been further accelerated through the reconstruction of population genomes to provide genome-centric context. Yet technical challenges with traditional shotgun metagenomics remain for computationally intense short-read assembly, strain heterogeneity within communities, and depth of coverage required for low-abundance microbes. In this Perspective, we highlight three main avenues for promising future developments, including coupling stable isotope probing and genome-resolved metagenomics, applying fluorescence-activated cell sorting approaches to target mini-metagenomes within a larger community, and utilizing single-molecule long-read and synthetic long-read technology to link mobile elements to host microbial cells. These developments on the horizon will undoubtedly advance genome-resolved metagenomic approaches and enable a better understanding of uncultivated microbes in their natural environments.

scholarly journals Supplementation of pigs diet with zinc and copper as alternative to conventional antimicrobials

2016 ◽  
Vol 19 (4) ◽  
pp. 917-924 ◽  
Author(s):  
B. Dębski
Keyword(s):  
Legal Status ◽  
Tap Water ◽  
Substantial Reduction ◽  
Farming Systems ◽  
Short Review ◽  
Growth Promoter ◽  
Feed Conversion ◽  
Growth Promoters ◽  
High Zinc ◽  
High Doses

Abstract Modern commercial pig farming systems inflict increased stress in animals, which often leads to various negative changes in the gastro-intestinal tract, especially in the case of piglets. Ban of antibiotics, used as growth promoters, has caused a need for alternatives to conventional antimicrobials in swine diets. Use of pre-/or probiotics, organic acids and plant extracts is often recommended, but it seems that zinc oxide and cooper salts, which were traditionally included in high doses to piglets diet, possess the highest efficacy. In commercial conditions feeding piglets with high doses of Zn and/or Cu stimulates piglets daily gain and decreases feed conversion factor. However, as heavy metals Zn and Cu tend to accumulate in soil and cause serious environmental pollution of soil and tap-water. Furthermore, high zinc concentrations (2500÷3000 mg/kg feed) in feed may have an impact on development of antimicrobial resistance, and may regulate the expression of genes that modify piglets’ immune response. Therefore, the use of high doses of ZnO and/or Cu salts, as growth promoter, has always been a subject of discussion, and caused different legal status of such treatment in various EU countries. This short review describes current European Food Safety Authority (EFSA) point of view on the use of ZnO in medicated feed. The higher bioavailability of recently introduced new sources or forms of these metals allows for substantial reduction of dietary inclusion rate, which should have a positive outcome for pigs health and the environment.

scholarly journals Cartographie Des Zones À Risque D’incendies De Forêts À L'aide Du SIG Et La Télédétection Dans L'arrière-Pays Du Port Tanger Med

2017 ◽  
Vol 13 (32) ◽  
pp. 205 ◽  
Author(s):  
Abderrahim Maktite ◽  
Ali Faleh
Keyword(s):  
Remote Sensing ◽  
Population Density ◽  
Fire Risk ◽  
Weather Conditions ◽  
Natural Environments ◽  
Strong Wind ◽  
High Population Density ◽  
Risk Map ◽  
Gis And Remote Sensing ◽  
Considerable Degradation

Moroccan natural environments, in recent decades, have undergone considerable degradation which is related primarily to the development of populations and the pressure they have exerted on natural resources. One aspect of this degradation is forest fire that has accelerated alarmingly. The study area belongs to the forest area of Tangier which covers an area of 42.000ha. The latter is known for its sensitivity to heat, especially because of the nature of the vegetation cover, weather conditions (frequent and strong wind), and high population density. The present work aims to prioritize the plot study area according to the degree of fire risk of forests using the model established by Dagorne Y. Duche in 1994. To achieve this goal, the application of GIS and Remote Sensing is required to develop a fire risk map in the hinterland of Tangier Mediterranean port.

scholarly journals Entomopathogens : role of insect pest management in crops

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
AMAR BAHADUR BAHADUR
Keyword(s):  
Pest Management ◽  
Crop Yields ◽  
Insect Pests ◽  
Insect Pest ◽  
Food Resource ◽  
Alternative Methods ◽  
Natural Environments ◽  
Insect Pest Management ◽  
Natural Ecosystems ◽  
Chemical Pesticides

Entomopathogens are microorganisms that pathogenic to insect pest. Several species of naturally occurring viz; fungi, bacteria, viruses and nematodes, infect a variety of insect pests and play an important role in agricultural crops controlling insect pest management.  This kind of biopesticide has many advantages and alternative to chemical insecticides, highly specific, safe, and environmentally sustainable. Pest problems are an almost inevitable part of agriculture. They occur largely because agricultural systems are simplified and modifications of natural ecosystems. Viruses, bacteria are host specific and fungi generally have broader host range and can infect both underground and aboveground pests, soil-dwelling nature nematodes are more suitable for managing soil pests. Growing crops in monoculture provides concentrated food resource that allows pest populations to achieve higher densities in natural environments. Some of the most important problems occur when pests develop resistance to chemical pesticides. These cause highly significant damage to crops, there are also threats from emerging new strains of pests. Crops cultivation can make the physico-chemical environment more favourable for pest activity. Agricultural pests are reducing the yield and quality of produce by feeding on crops, transmitting diseases. Agricultural production significantly loss crop yields, suggest that improvements in pest management are significant forward for improving yields. Crop growers are under immense pressure to reduce the use of chemical pesticides without sacrificing yields, but at the same time manage of pests is becoming difficult due to pesticide resistance and the decreasing availability of products. Alternative methods are needed urgently. These need to be used as part of Integrated Pest Management safety and environmental impact.  

scholarly journals Response of endemic and exotic earthworm communities to ecological restoration

2016 ◽  
Author(s):  
Stéphane Boyer ◽  
Young-Nam Kim ◽  
Mike H Bowie ◽  
Marie-Caroline Lefort ◽  
Nicholas M Dickinson
Keyword(s):  
New Zealand ◽  
Exotic Species ◽  
Environmental Changes ◽  
Farming Systems ◽  
Native Vegetation ◽  
Native Plant ◽  
Plant Restoration ◽  
Exotic Earthworms ◽  
Study Sites ◽  
The Impact

New Zealand has 23 exotic and more than 200 endemic earthworm species. Endemic earthworms disappeared quickly after vegetation clearance and land conversion to agriculture from the early C19th. Environmental changes associated with agronomic practices are believed to have been the main drivers for their disappearance. Exotic earthworms introduced from Europe have since largely replaced endemic earthworms into farming systems and have been intentionally propagated to increase production. Little is known about potential competition between endemic and exotic earthworms in New Zealand, and the capacity of exotic earthworms to extend their range into native habitats. Using two sites in the South Island of New Zealand, we investigated the impact of restoring native vegetation on earthworm communities. The study sites were Quail Island (Banks Peninsula), which has been undergoing native plant restoration for more than 30 years, and the Punakaiki Coastal Restoration Project (West Coast) where 130,000 native trees have been planted in retired pasture in the last seven years. At each site, soil samples (20 x 20 x 20 cm) were collected and hand sorted for earthworms. Sequential restoration plantings revealed that recolonisation by endemic earthworms increases with time after restoration at the two sample sites. With increasing age of the restoration, the biomass of endemic earthworm significantly increased, as did abundance at Punakaiki. However, exotic species did not disappear after restoration of native vegetation, even after 30 years in Quail Island. The persistence of exotic species leads to the cohabitation of the two communities and potential for interspecific competition.

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