• Title/Summary/Keyword: Abiotic factors.

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Studies on the Seasonal Incidence of the Whitefly (Dialeuropora decempuncta Quaintance and Baker) Causing Leaf Curl on Mulberry in Relation to Abiotic Factors

  • Bandyopadhyay, U.K.;Sahu, P.K.;Raina, S.K.;Santhakumar, M.V.;Chakraborty, N.;Sen, S.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.1 no.1
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    • pp.65-71
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    • 2000
  • A study was conducted to examine the relationship between abiotic factors and the population of white-fly (Dialeuropora decempuncta) in mulberry field. The study reveals that relationship between abiotic factors and the whitefly population is very much existent like other pests in other agricultural crops. Duration and time of distinct occurrence of whitefly in mulberry is influenced by the abiotic conditions of field. Abiotic parameters of previous month are more important in influencing the intensity of the pest than the current abiotic factors. Not all the abiotic factors are equally important but factors like minimum temperature, fluctuation in temperature during the days minimum relative humidity, fluctuation in relative humidity and rainfall are the major important lactors in influencing the intensity of the pest under consideration.

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Studies on the Integrated Stream Naturalness Assessment Based on Abiotic and Biotic Factors (비생물 및 생물 요인에 기초한 통합적 하천자연도 평가기법에 관한 연구)

  • Pyo, Jae-Hun;Mun, Hyeong-Tae
    • Journal of Environmental Impact Assessment
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    • v.20 no.1
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    • pp.61-69
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    • 2011
  • Integrated stream naturalness based on abiotic and biotic factors were developed. Abiotic factors considered in this study were types of land use in the riparian area, river bank and high water bed streamside, revetment, bed substrate and artificial construction of streamside. Biotic factors included types of vegetation, assemblages of fish, macroinvertebrate, bird and mammal(Otter) in streams. The presence/absence of legal species and biological assessment index were also weighted as important parameters in this study. Scoring criteria selected for each matrix was five rating system; 1=poor, 2=moderate, 3=fair, 4=good, 5=excellent. Numerical ratings for the matrix were then summed. This resulted in a minimum score of 13 if all matrix at a site were poor, and a maximum score of 65 if all matrix were excellent. Five grade system from poor(I) to excellent condition(V) was employed. To verify its validity in natural environment, the evaluation system was applied to the Gapchun stream which is a test bed selected. Our result showed that stream naturalness of each reach was clearly distinguished by biotic and abiotic characteristics. Determination of correlation coefficient between abiotic and biotic factors was also high ($R^2=0.96$, p<0.05). In conclusion, assessment for stream naturalness reflecting abiotic and biotic factors was useful method representing stream integrated.

Community Structure of Benthic Macroinvertebrate Affected by Lake Water and Sewage Effluent at Urban Stream in Gwangju, Korea

  • Yoon, Sang-Hoon;Jung, Suk-Kyeong;Seo, Gwang-Yeob;Cho, Young-Gwan
    • Korean Journal of Ecology and Environment
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    • v.50 no.3
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    • pp.325-336
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    • 2017
  • The ecosystem in the Gwangju Stream has taken a wide range of disturbance such as the discharging water of sewage treatment plant, the lake water and the river water from different water system over the past decade. This study was figured out some significant influence factors by analyzing the relationship between biotic and abiotic factors in the urban stream. Abiotic components included 15 water quality variables which were measured in five sampling sites along the stream from October 2014 to July 2015, whereas the benthic macroinvertebrates found in those sites were used to estimate various biotic indices representing the ecological status of the community. The results of correlation analyses indicated that abiotic factors by human activities affected on the inhabitation of benthic macroinvertebrates more than biotic factors. The results of cluster analyses and ANOVA tests also showed that biotic and abiotic characteristics were clearly different in season. The main influence factors of cluster analysis by sites were $NH_3-N$, EPT(I) and DO. It was considered that more various statistical analyses would be necessary to find some different relationships and influence factors between biotic and abiotic variables in the urban stream.

Biological roles of NAC transcription factors in the regulation of biotic and abiotic stress responses in solanaceous crops

  • Tweneboah, Solomon;Oh, Sang-Keun
    • Journal of Plant Biotechnology
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    • v.44 no.1
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    • pp.1-11
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    • 2017
  • Evolutionary studies conducted on NAC (NAM, ATAF1&2, and CUC2) genes for all major groups of land plants, indicate the presence of the NAC subfamilies, even in the early land plants. The varied roles played by NAC proteins in plant growth and development range from the formation of shoot apical meristem, floral organ development, reproduction, lateral shoot development, and defense responses to biotic and abiotic stresses. Considering the value and importance of solanaceous crops, the study of NAC proteins in these plants needs to be intensified. This will help to identify and functionally characterize their promoters, which will subsequently aid in engineering plants with improved performance under stressful conditions. In this review, the functionally characterized NAC transcription factors specific to tomato, potato, tobacco, chili pepper and eggplant (aubergine) are summarized, clearly indicating their biological functions in the defense mechanism of the plants, against biotic and abiotic stresses.

Isolation of Multi-Abiotic Stress Response Genes to Generate Global Warming Defense Forage Crops

  • Ermawati, Netty;Hong, Jong Chan;Son, Daeyoung;Cha, Joon-Yung
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.41 no.4
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    • pp.242-249
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    • 2021
  • Forage crop management is severely challenged by global warming-induced climate changes representing diverse a/biotic stresses. Thus, screening of valuable genetic resources would be applied to develop stress-tolerant forage crops. We isolated two NAC (NAM, ATAF1, ATAF2, CUC2) transcription factors (ANAC032 and ANAC083) transcriptionally activated by multi-abiotic stresses (salt, drought, and cold stresses) from Arabidopsis by microarray analysis. The NAC family is one of the most prominent transcription factor families in plants and functions in various biological processes. The enhanced expressions of two ANACs by multi-abiotic stresses were validated by quantitative RT-PCR analysis. We also confirmed that both ANACs were localized in the nucleus, suggesting that ANAC032 and ANAC083 act as transcription factors to regulate the expression of downstream target genes. Promoter activities of ANAC032 and ANAC083 through histochemical GUS staining again suggested that various abiotic stresses strongly drive both ANACs expressions. Our data suggest that ANAC032 and ANAC083 would be valuable genetic candidates for breeding multi-abiotic stress-tolerant forage crops via the genetic modification of a single gene.

The Distribution of Cellular Slime Molds in Forests of Seoul Area and Relationship between Cellular Slime Molds and Soil Microorganisms (서울지역 삼림에서 세포성 점균의 분포와 토양 미생물과의 관계)

  • 홍정림;장남기
    • Asian Journal of Turfgrass Science
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    • v.10 no.3
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    • pp.247-262
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    • 1996
  • In this study, the distribution of dictyostelid cellular slime molds was investigated from F, H and $A_1$ horizon of pinus, oak forests in Mt. Puk'an, Mt. Nam and Mt. Kwanak. The relationship of cellular slime molds with other soil microorganisms and abiotic factors were analyzed. The six species were isolated as follows: Polysphondlium pallidurn, Dictyostelium purpureum, D. mucoroides, D. crassicaule, D. capitatum, D. implicatum. The dominant species in pinus forests was P. pallidum, and in oak forests it was D. macro ides. In Mt. Nam, D. mucoroides and P. pallidum were isolated at only oak forest. The Correlations of slime mold abundance with bacteria were significant. Even though positive correlations of cellular slime molds with actinomycetes or fungi were not significant, correlations between soil microorganisms were analyzed. Correlation coefficients were high in Mt. Kwanak(r=0.5921) and Mt. Nam(r=0.7243) at significant level P<0.01. There were significant correlations between total slime molds and abiotic factors. It supports that cellular slime molds are limited by foods in nature. In low level of pH, water content and organic matter, that community diversity is more affected by bacteria whose organic degradation capacity is regulated by interactions of soil microorgaisms. Key words: Cellular slime molds, Soil microorganisms, Correlations, Abiotic factors.

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Role of Scientific Reasoning in Elementary School Students' Construction of Food Pyramid Prediction Models (초등학생들의 먹이 피라미드 예측 모형 구성에서 과학적 추론의 역할)

  • Han, Moonhyun
    • Journal of Korean Elementary Science Education
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    • v.38 no.3
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    • pp.375-386
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    • 2019
  • This study explores how elementary school students construct food pyramid prediction models using scientific reasoning. Thirty small groups of sixth-grade students in the Kyoungki province (n=138) participated in this study; each small group constructed a food pyramid prediction model based on scientific reasoning, utilizing prior knowledge on topics such as biotic and abiotic factors, food chains, food webs, and food pyramid concepts. To understand the scientific reasoning applied by the students during the modeling process, three forms of qualitative data were collected and analyzed: each small group's discourse, their representation, and the researcher's field notes. Based on this data, the researcher categorized the students' model patterns into three categories and identified how the students used scientific reasoning in their model patterns. The study found that the model patterns consisted of the population number variation model, the biological and abiotic factors change model, and the equilibrium model. In the population number variation model, students used phenomenon-based reasoning and relation-based reasoning to predict variations in the number of producers and consumers. In the biotic and abiotic factors change model, students used relation-based reasoning to predict the effects on producers and consumers as well as on decomposers and abiotic factors. In the equilibrium model, students predicted that "the food pyramid would reach equilibrium," using relation-based reasoning and model-based reasoning. This study demonstrates that elementary school students can systematically elaborate on complicated ecology concepts using scientific reasoning and modeling processes.

A Study on Importance of Assessment Factors and Indicators of Natural Ecosystem for Environmentally Friendly Land Conservation (환경친화적 국토보전을 위한 자연생태계 평가요인 및 평가지표의 중요도에 관한 연구)

  • You, Ju-Han;Park, Kyung-Hun;Jung, Sung-Gwan
    • Journal of Environmental Impact Assessment
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    • v.14 no.4
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    • pp.165-177
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    • 2005
  • This study was carried out to offer the basic methodology of the system and model to objectively assess the natural ecosystem for environmentally friendly land conservation and present the alternative plan on establishing the environmental policy. The results of this study were as follows. We selected four assessment factors associated with biotic, abiotic, qualitative, and functional factors. Also, there were extracted fifty-six indicators including density, total nitrogen, hemeroby degree, and goods production. The assessment factor showed that biotic one was very important. The importance of indicators were analyzed that rare and endangered plant was important in biotic factor, in case of abiotic, qualitative, and functional factors, organic matter, landscape diversity, and conservation of ecosystem were greatly important. The results of factor analysis on the characteristics of indicators, classified biotic factor into six factors including a structural one, abiotic factor as a soil and physical one, qualitative factor as five ones including hierarchical one, and functional factor as public and conservational one. In the results of analysis on assessment model, R-square of biotic factor was 51.7%, those of abiotic, qualitative, and functional one were each 58.4%, 44.2%, and 39.3%, and statistical problem was no existence. In future, to develop the assessement model and methodology of sustainable natural ecosystem, we will have to achieve the integrated model and grouping by assessment factor.

Influence of abiotic factors on seasonal incidence of pests of tasar Silkworm Antheraea mylitta D.

  • Siddaiah, Aruna A.;Prasad, Rajendra;Rai, Suresh;Dubey, Omprakash;Satpaty, Subrat;Sinha, Ravibhushan;Prsad, Suraj;Sahay, Alok
    • International Journal of Industrial Entomology and Biomaterials
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    • v.29 no.1
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    • pp.135-144
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    • 2014
  • Rearing of tropical tasar silkworm, Antheraea mylitta Drury is mainly conducted in outdoor on Terminalia tomentosa W. & A. a nature grown primary host plant available in forest and also on raised primary host plant Terminalia arjuna Bedd. Temperature, relative humidity and rainfall are the main environmental factors for occurrence of pests (parasites and predators) of tasar silkworm during I, II and III crop rearing in the tropical tasar producing zones. The present study was aimed to study the influence of abiotic factors on prevalence of tasar silkworm pests. The study was conducted at different agro-climatic regions viz., Central Tasar Research &Training Institute, Ranchi, Jharkhand, Regional Extension Centre, Katghora, Chattisgarh and Regional Extension Centre, Hatgamaria during 2010-13 covering 3 seed crop and 6 commercial crops. Data on incidence of tropical tasar silkworm endo-parasitoids like Uzi Fly, Blepharipa zebina Walker and Ichneumon fly (Yellow Fly), Xathopimpla pedator, Fabricius and Predators such as Stink bug (Eocanthecona furcellata Wolf), Reduviid bug (Sycanus collaris Fabricius) and Wasp (Vespa orientalis Linnaeus) was recorded Weekly. The meteorological data was collected daily. Data was collected from 4 different agro-climatic zones of tasar growing areas. Analysis of the data revealed a significant negative correlation between abiotic factors and incidence of ichneumon fly and uzi fly. Based on the 3 years data on prevalence of pests region-wise pest calendars and prediction models were developed.

Assembly and Function of Seed Endophytes in Response to Environmental Stress

  • Yong-Lan Wang;Han-Bo Zhang
    • Journal of Microbiology and Biotechnology
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    • v.33 no.9
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    • pp.1119-1129
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    • 2023
  • Seeds are colonized by diverse microorganisms that can improve the growth and stress resistance of host plants. Although understanding the mechanisms of plant endophyte-host plant interactions is increasing, much of this knowledge does not come from seed endophytes, particularly under environmental stress that the plant host grows to face, including biotic (e.g., pathogens, herbivores and insects) and abiotic factors (e.g., drought, heavy metals and salt). In this article, we first provided a framework for the assembly and function of seed endophytes and discussed the sources and assembly process of seed endophytes. Following that, we reviewed the impact of environmental factors on the assembly of seed endophytes. Lastly, we explored recent advances in the growth promotion and stress resistance enhancement of plants, functioning by seed endophytes under various biotic and abiotic stressors.