Characteristics of fungal communities and the sources of mold contamination in mildewed tobacco leaves stored under different climatic conditions

2021 ◽  
Author(s):  
Jiaxi Zhou ◽  
Yu Cheng ◽  
Lifei Yu ◽  
Jian Zhang ◽  
Xiao Zou
Keyword(s):  
Climatic Conditions ◽  
Fungal Communities ◽  
Tobacco Leaves

scholarly journals Are Wildfires a Threat to Fungi in European Pinus Forests? A Case Study of Boreal and Mediterranean Forests

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 309 ◽  
Author(s):  
Iván Franco-Manchón ◽  
Kauko Salo ◽  
Juan Oria-de-Rueda ◽  
José Bonet ◽  
Pablo Martín-Pinto
Keyword(s):  
Boreal Forests ◽  
Fungal Diversity ◽  
Community Dynamics ◽  
Forest Products ◽  
Climatic Conditions ◽  
Fungal Communities ◽  
Mediterranean Forests ◽  
Natural Forests ◽  
Edible Fungi ◽  
Pinus Species

Natural forests and plantations of Pinus are ecologically and economically important worldwide, producing an array of goods and services, including the provision of non-wood forest products. Pinus species play an important role in Mediterranean and boreal forests. Although Pinus species seem to show an ecological adaptation to recurrent wildfires, a new era of mega fires is predicted, owing to climate changes associated with global warming. As a consequence, fungal communities, which are key players in forest ecosystems, could be strongly affected by these wildfires. The aim of this study was to observe the fungal community dynamics, and particularly the edible fungi, in maritime (Pinus pinaster Ait.), austrian pine (Pinus nigra J.F. Arnold), and scots pine (Pinus sylvestris L.) forests growing under wet Mediterranean, dry Mediterranean, and boreal climatic conditions, respectively, by comparing the mushrooms produced in severely burned Pinus forests in each area. Sporocarps were collected during the main sampling campaigns in non-burned plots, and in burned plots one year and five years after fire. A total of 182 taxa, belonging to 81 genera, were collected from the sampled plots, indicating a high level of fungal diversity in these pine forests, independent of the climatic conditions. The composition of the fungal communities was strongly affected by wildfire. Mycorrhizal taxa were impacted more severely by wildfire than the saprotrophic taxa, particularly in boreal forests—no mycorrhizal taxa were observed in the year following fire in boreal forests. Based on our observations, it seems that fungal communities of boreal P. sylvestris forests are not as adapted to high-intensity fires as the Mediterranean fungal communities of P. nigra and P. pinaster forests. This will have an impact on reducing fungal diversity and potential incomes in rural economically depressed areas that depend on income from foraged edible fungi, one of the most important non-wood forest products.

Composition of soil bacterial and fungal communities in relation to vegetation composition and soil characteristics along an altitudinal gradient

2020 ◽  
Vol 97 (1) ◽  
Author(s):  
Mohammad Bayranvand ◽  
Moslem Akbarinia ◽  
Gholamreza Salehi Jouzani ◽  
Javad Gharechahi ◽  
Yahya Kooch ◽  
...  
Keyword(s):  
Soil Quality ◽  
Forest Floor ◽  
Fungal Diversity ◽  
Altitudinal Gradient ◽  
Climatic Conditions ◽  
Fungal Communities ◽  
Vegetation Composition ◽  
Soil Bacterial ◽  
Favorable Conditions ◽  
Altitude Level

ABSTRACT The objective of the present study was to evaluate how altitudinal gradients shape the composition of soil bacterial and fungal communities, humus forms and soil properties across six altitude levels in Hyrcanian forests. Soil microbiomes were characterized by sequencing amplicons of selected molecular markers. Soil chemistry and plant mycorrhizal type were the two dominant factors explaining variations in bacterial and fungal diversity, respectively. The lowest altitude level had more favorable conditions for the formation of mull humus and exhibited higher N and Ca contents. These conditions were also associated with a higher proportion of Betaproteobacteria, Acidimicrobia, Acidobacteria and Nitrospirae. Low soil and forest floor quality as well as lower bacterial and fungal diversity characterized higher altitude levels, along with a high proportion of shared bacterial (Thermoleophilia, Actinobacteria and Bacilli) and fungal (Eurotiomycetes and Mortierellomycota) taxa. Beech-dominated sites showed moderate soil quality and high bacterial (Alphaproteobacteria, Acidobacteria, Planctomycetes and Bacteroidetes) and fungal (Basidiomycota) diversity. Particularly, the Basidiomycota were well represented in pure beech forests at an altitude of 1500 m. In fertile and nitrogen rich soils with neutral pH, soil quality decreased along the altitudinal gradient, indicating that microbial diversity and forest floor decomposition were likely constrained by climatic conditions.

scholarly journals Climatic factors determine the yield and quality of Honghe flue-cured tobacco

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zuoxin Tang ◽  
Lulu Chen ◽  
Zebin Chen ◽  
Yali Fu ◽  
Xiaolu Sun ◽  
...  
Keyword(s):  
Climatic Factors ◽  
Climatic Conditions ◽  
Chemical Component ◽  
Chemical Components ◽  
Available Phosphorus ◽  
Tobacco Leaves ◽  
Yield And Quality ◽  
Soil Clay ◽  
Supply Capacity

AbstractFlue-cured tobacco (Nicotiana tabacum L.) is a major cash crop in Yunnan, China, and the yield, chemical components, and their proportions decide the quality of tobacco leaves. To understand the effects of environmental factors (soil and climatic factors) on the yield and quality of flue-cured tobacco and determine the main regulating factors, we selected three flue-cured tobacco cultivars [K326, Yunyan87 (Yun87), and Honghuadajinyuan (Hongda)] grown in the Honghe Tobacco Zone. Indices related to yield and economic traits, chemical component properties, soil physical and chemical properties, and climatic factors at different planting sites, were evaluated. We used variance analysis, correlation analysis, and redundancy analysis (RDA) in this study. The results showed that the yield and chemical component properties of flue-cured tobacco, except for the number of left leaves and plant total sugar (PTS) content, were significantly correlated with climatic factors. Particularly, the yield increased in drier and sunnier weather. In terms of the carbon supply capacity, PTS, petroleum ether (PPE), and starch contents (PS) were higher under high-altitude and high-latitude climatic conditions, whereas for the nitrogen supply capacity, plant nitrogen (PTN) and nicotine (PN) contents improved under low-altitude and low-latitude climatic conditions. PTS, reducing sugar (PRS), potassium (PTK), chlorine (PCL), and PPE contents were negatively related to soil clay content, soil pH, and soil organic matter, whereas PRS and PTK contents were positively correlated with alkali-hydrolyzed nitrogen (AN). According to RDA, the soil clay, AN, available phosphorus (AP), and soil chlorine content (SCL) strongly affected the quality of flue-cured tobacco. The quality of the K326 and Yun87 cultivars was mostly influenced by moisture, whereas the quality of the Hongda cultivar was mostly affected by temperature. In conclusion, compared with soil properties, climatic factors more significantly affect the yield and quality of Honghe flue-cured tobacco leaves.

scholarly journals Factors Influencing the Formation of Tobacco-Specific Nitrosamines in French Air-Cured Tobaccos in Trials and at the Farm Level

2005 ◽  
Vol 21 (6) ◽  
pp. 305-320 ◽  
Author(s):  
C deRoton ◽  
A Wiernik ◽  
I Wahlberg ◽  
B Vidal
Keyword(s):  
Relative Humidity ◽  
Nitrogen Fertilization ◽  
Low Temperatures ◽  
Agricultural Practices ◽  
Climatic Conditions ◽  
Genetic Trait ◽  
Tobacco Leaves ◽  
Factors Influencing ◽  
Tobacco Specific Nitrosamines ◽  
And Storage

AbstractSeveral trials the results of which are compiled in this paper, were carried out at the Tobacco Institute of Bergerac (ITB) and in the area nearby from 1996 to 2003. The objective was to study the formation of tobacco-specific nitrosamines (TSNA) in dark air-cured and burley tobaccos during curing and post-curing treatment under the conditions of cultivation, curing and storage commonly applied by the growers in the south-western part of France. For experimental purposes special treatments were performed in certain trials.The results showed that the main genetic trait involved in the formation of TSNA is the propensity of a variety to convert nicotine to nornicotine (NN). In addition, the ability of a variety to lose water rapidly limits the formation of nitrite and hence also the formation of TSNA. Furthermore, agricultural practices that led to an increase of alkaloid concentrations in the tobacco leaves also led to an increase of TSNA concentration. Priming, a mode of harvest which speeds up the cure, as compared to stalk-cutting, as well as low temperatures during curing, limit the formation of TSNA, but do not yield tobaccos of the best quality. Ventilation in the barn plays a major role, and the leaves cured in well ventilated curing structures, such as plastic sheds, generally contained smaller amounts of TSNA than leaves cured in a conventional curing barn. The results also indicated that the TSNA concentrations may increase after the end of cure, if the cured tobaccos were kept hanging in the barn under humid conditions. The concentration of TSNA may also continue to increase, whereas nitrite concentrations tend to decrease, when the leaves are kept in bales.It can be concluded that the French climatic conditions with moderate temperatures and low relative humidity at the time of curing, are favourable for the production of air-cured tobaccos with a good quality and low TSNA concentrations (1.5-3.5 µg/g), provided that the variety has low NN content, the nitrogen fertilization is moderate, the curing is performed in a well ventilated environment, the tobacco is taken down and stripped as soon as it is cured, and the bales are stored as briefly as possible before the leaves are threshed and stabilized.

Low temperature x-ray microanalysis of frozen-hydrated tobacco leaves

1984 ◽  
Vol 42 ◽  
pp. 284-285
Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes
Keyword(s):  
Low Temperature ◽  
Lemna Minor ◽  
Root Tips ◽  
Tobacco Leaves ◽  
X Ray ◽  
Whole Cells ◽  
Carbon Coated ◽  
The Right ◽  
Beam Currents ◽  
The University

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.

Effect of climatic conditions and soil type on antioxidant compounds in organic and conventional blueberries (Vaccinium corymbosum L.)

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
MD López ◽  
P Jara ◽  
S Fischer ◽  
R Wilckens ◽  
H Serri ◽  
...  
Keyword(s):  
Soil Type ◽  
Vaccinium Corymbosum ◽  
Climatic Conditions ◽  
Antioxidant Compounds

Impact of roof shading on building energy performance in warm & humid climatic places of India

2020 ◽  
pp. 50-64
Author(s):  
Kuladeep Kumar Sadevi ◽  
Avlokita Agrawal
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Performance ◽  
General Assumption ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Passive Cooling ◽  
Base Case ◽  
U Value ◽  
The Impact

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.

Experimentally altered rainfall regimes and host root traits affect grassland arbuscular mycorrhizal fungal communities

2019 ◽  
Author(s):  
Coline Deveautour ◽  
Suzanne Donn ◽  
Sally Power ◽  
Kirk Barnett ◽  
Jeff Powell
Keyword(s):  
Fungal Community ◽  
Community Assembly ◽  
Root Length ◽  
Specific Root Length ◽  
Root Traits ◽  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Rainfall Regime ◽  
Precipitation Regimes ◽  
Rainfall Regimes

Future climate scenarios predict changes in rainfall regimes. These changes are expected to affect plants via effects on the expression of root traits associated with water and nutrient uptake. Associated microorganisms may also respond to these new precipitation regimes, either directly in response to changes in the soil environment or indirectly in response to altered root trait expression. We characterised arbuscular mycorrhizal (AM) fungal communities in an Australian grassland exposed to experimentally altered rainfall regimes. We used Illumina sequencing to assess the responses of AM fungal communities associated with four plant species sampled in different watering treatments and evaluated the extent to which shifts were associated with changes in root traits. We observed that altered rainfall regimes affected the composition but not the richness of the AM fungal communities, and we found distinctive communities in the increased rainfall treatment. We found no evidence of altered rainfall regime effects via changes in host physiology because none of the studied traits were affected by changes in rainfall. However, specific root length was observed to correlate with AM fungal richness, while concentrations of phosphorus and calcium in root tissue and the proportion of root length allocated to fine roots were correlated to community composition. Our study provides evidence that climate change and its effects on rainfall may influence AM fungal community assembly, as do plant traits related to plant nutrition and water uptake. We did not find evidence that host responses to altered rainfall drive AM fungal community assembly in this grassland ecosystem.

Temporal dynamics of mycorrhizal fungal communities and co-associations with grassland plant communities following experimental manipulation of rainfall

2019 ◽  
Author(s):  
Coline Deveautour ◽  
Sally Power ◽  
Kirk Barnett ◽  
Raul Ochoa-Hueso ◽  
Suzanne Donn ◽  
...  
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Fungal Community ◽  
Mycorrhizal Fungi ◽  
Temporal Dynamics ◽  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Plant Responses ◽  
Rainfall Regimes

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.

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