• Journal of Ecology and Environment
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• 제35권4호
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• pp.351-358
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• 2012

To investigate the environmental adaptation and ecophysiological characteristics of Suaeda maritima and S. asparagoides under saline conditions, plant growth and density were analyzed according to environmental changes of habitats. The total ion content of soil decreased with time, which was caused by the predominance of exchangeable $Na^+$ and $Cl^-$ in the upper layers. The population of S. maritima was more densely distributed in the region with higher ion contents of $Cl^-$, $Mg^{2+}$, $K^+$ and $Na^+$ than the population of S. asparagoides. Both species were showed a decreased population density according to increases in plant growth. Under the conditions of a salt field, S. maritima and S. asparagoides contained high inorganic ions to maintain low water potential, but low water soluble carbohydrate contents. In the case of free amino acid, S. maritima showed an especially high proline content, and contained rather large amounts of free amino acids, whereas S. asparagoides did not. Both species showed high inorganic ion contents in the leaves, which might be a mechanism of avoiding the ionic toxicity by diluting the accumulated ionic concentration with a high ratio of water content to dry weight. This result suggests that S. maritima seems to adapt to saline conditions by accumulating proline in addition to inorganic ions. S. asparagoides seems to adapt by osmoregulation processes, using inorganic ions rather than free amino acids.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1517-1526
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• 2018

Investigating bacterial diversity and its metabolic capabilities is crucial for interpreting the ecological patterns in a desert environment and assessing the presence of exploitable microbial resources. In this study, we evaluated the spatial heterogeneity of physicochemical parameters, soil bacterial diversity and metabolic adaptation at meter scale. Soil samples were collected from two quadrats of a desert (Thar Desert, India) with a hot, arid climate, very little rainfall and extreme temperatures. Analysis of physico-chemical parameters and subsequent variance analysis (p-values < 0.05) revealed that sulfate, potassium and magnesium ions were the most variable between the quadrats. Microbial diversity of the two quadrats was studied using Illumina bar-coded sequencing by targeting V3-V4 regions of 16S rDNA. As for the results, 702504 high-quality sequence reads, assigned to 173 operational taxonomic units (OTUs) at species level, were examined. The most abundant phyla in both quadrats were Actinobacteria (38.72%), Proteobacteria (32.94%), and Acidobacteria (9.24%). At genus level, Gaiella represented highest prevalence, followed by Streptomyces, Solirubrobacter, Aciditerrimonas, Geminicoccus, Geodermatophilus, Microvirga, and Rubrobacter. Between the quadrats, significant difference (p-values < 0.05) was found in the abundance of Aciditerrimonas, Geodermatophilus, Geminicoccus, Ilumatobacter, Marmoricola, Nakamurella, and Solirubrobacter. Metabolic functional mapping revealed diverse biological activities, and was significantly correlated with physicochemical parameters. The results revealed spatial variation of ions, microbial abundance and functional attributes in the studied quadrats, and patchy nature in local scale. Interestingly, abundance of the biotechnologically important phylum Actinobacteria, with large proposition of unclassified species in the desert, suggested that this arid environment is a promising site for bioprospection.

• 농업과학연구
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• 제46권4호
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• pp.769-779
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• 2019

Chilli peppers are predominantly cultivated in open field systems under abiotic and biotic stress conditions. Abiotic and biotic factors have a considerable effect on plant performance, fruit quantity, and quality. Chilli peppers grow well in a tropical climate due to their adaptation to warm and humid regions with temperatures ranging from 18 to 30℃. Nowadays, chilli peppers are cultivated all around the world under different climatic conditions, and their production is gradually expanding. Expected climate changes will likely cause huge and complex ecological consequences; high temperature, heavy rainfall, and drought have adverse effects on the vegetative and generative development of all agricultural crops including chilli peppers. To gain better insight into the effect of climate change, the growth, photosynthetic traits, morphological and physiological characteristics, yield, and fruit parameters of chilli peppers need to be studied under simulated climate change conditions. Moreover, it is important to develop alternative agrotechnologies to maintain the sustainability of pepper production. There are many conceivable ideas and concepts to sustain crop production under the extreme conditions of future climate change scenarios. Therefore, this review provides an overview of the adverse impacts of climate change and discusses how to find the best solutions to obtain a stable chilli pepper yield.

• The Korean Journal of Ecology
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• 제18권3호
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• pp.323-332
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• 1995

Effects of wintering and temperature on nitrogen fixation activity of nodules of Melilotus suaveolens Ledeb. grown in the field and growth chamber conditions were investigated. The biennial plants transfered to the growth chamber from winter field recovered the activity in 3 weeks of incubation and attained the maximum rate of $153{\mu}mol\;C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$ in 5 weeks. When root nodules which adapted to different temperatures, were pretreated with 10, 20 and $30^{\circ}C$ for 1 hour, and then transfered to $30^{\circ}C$, nitrogen fixation activity was promoted in the nodules exposed to lower field temperature ($12^{\circ}C$) with 1$0^{\circ}C$ pretreatment. M. suaveolens maintained nitrogen fixation activity in the wide range of temperatures, and was more tolerant to lower temperature than those of other woody leguminous plants, Diurnal changes of nodule activity showed increase with sunrise and decrease with sunset during spring and autumn, but the activity was inhibited during July and August because of high temperature with stron irradiation. Nitrogen fixation activity of annual plant appeared in mid-April, and showed two peaks (104 and 43 mol $C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$) in July and September, and then disappeared after October. Nitrogen fixation activity of biennial plant reappeared in mid-March after wintering and attained two peaks (102 and 82 ${\mu}mol\;C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$) in April and June of flowering period, and then disappeared after July due to plant withering by severe drought.

• Animal cells and systems
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• 제2권4호
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• pp.455-462
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• 1998

A survey was conducted on the inorganic and organic solute patterns of plants in connection with nitrate metabolism according to different light regimes (1.9, 16.0, 91.5 $Wm^{-2}$). Besides measuring in vivo NRA, we also quantitatively analyzed ater-soluble inorganic ions, organic acids, low molecular weight carbohydrates, amino aciss and total N (% DW). Among 4 Carex species, C. pilosa is known as shade-adapted species and the others as half (C. gracilis) to full (C. rostrata & C. distans) light-adapted species. Compared to species adapted to high light intensity, shade-adapted C. pilosa showed reduced productivity under the highest light intensity. In general, nitrate and amino acid levels decreased at higher light intensity, while sugar and organic acid concentrations increased. In C. pilosa osmolality tended to rise with increasing light intensity, while in the other species it tended to fall. Under low light intensity, the drop in soluble carbohydrate contents is osmotically compensated for by an enhanced nitrate concentration. It is concluded that competition between nitrate and $CO_2$reduction for reductants and ATP from photosynthesis may have important ecological consequences for the adaptation of plants to low or high light conditions. Additionally, the patterns of ionic changes due to increased light intensities were essentially the same in all selected species, indicating similar characteristics of heir mineral ion and organic acid metabolism as well as in field-grown Carex species.

• 한국농림기상학회지
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• 제12권1호
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• pp.63-73
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• 2010

A comprehensive mapping project for agroclimatic zoning in South Korea will end by April 2010, which has required 4 years, a billion won (ca. 0.9 million US dollars) and 22 experts from 7 institutions to complete it. The map database from this project may be categorized into primary, secondary and analytical products. The primary products are called "high definition" digital climate maps (HD-DCMs) and available through the state of the art techniques in geospatial climatology. For example, daily minimum temperature surfaces were prepared by combining the climatic normals (1971-2000 and 1981-2008) of synoptic observations with the simulated thermodynamic nature of cold air by using the raster GIS and microwave temperature profiling which can quantify effects of cold air drainage on local temperature. The spatial resolution of the gridded climate data is 30m for temperature and solar irradiance, and 270m for precipitation. The secondary products are climatic indices produced by statistical analysis of the primary products and includes extremes, sums, and probabilities of climatic events relevant to farming activities at a given grid cell. The analytical products were prepared by driving agronomic models with the HD-DCMs and dates of full bloom, the risk of freezing damage, and the fruit quality are among the examples. Because the spatial resolution of local climate information for agronomic practices exceeds the current weather service scale, HD-DCMs and the value-added products are expected to supplement the insufficient spatial resolution of official climatology. In this lecture, state of the art techniques embedded in the products, how to combine the techniques with the existing geospatial information, and agroclimatic zoning for major crops and fruits in South Korea will be provided.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.575-584
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• 2012

Listeria monocytogenes is an important foodborne pathogen that comprises four genetic lineages: I, II, III, and IV. Of these, lineage II is frequently recovered from foods and environments and responsible for the increasing incidence of human listeriosis. In this study, the phylogenetic structure of lineage II was determined through sequencing analysis of the ascB-dapE internalin cluster. Fifteen sequence types proposed by multilocus sequence typing based on nine housekeeping genes were grouped into three distinct sublineages, IIA, IIB, and IIC. Organization of the ascB-dapE internalin cluster could serve as a molecular marker for these sublineages, with inlGHE, inlGC2DE, and inlC2DE for IIA, IIB, and IIC, respectively. These sublineages displayed specific genetic and phenotypic characteristics. IIA and IIC showed a higher frequency of recombination (${\rho}/{\theta}$). However, recombination events had greater effect (r/m) on IIB, leading to its high nucleotide diversity. Moreover, IIA and IIB harbored a wider range of internalin and stress-response genes, and possessed higher nisin tolerance, whereas IIC contained the largest portion of low-virulent strains owing to premature stop codons in inlA. The results of this study indicate that IIA, IIB, and IIC might occupy different ecological niches, and IIB might have a better adaptation to a broad range of environmental niches.

• Journal of Ecology and Environment
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• 제43권4호
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• pp.332-340
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• 2019

Background: Studies of morphological variation within and among populations provide an opportunity to understand local adaptation and potential patterns of gene flow. To study the evolutionary divergence patterns of Schlegel's Japanese gecko (Gekko japonicus) across its distribution, we analyzed data for 15 morphological characters of 324 individuals across 11 populations (2 in China, 4 in Japan, and 5 in Korea). Results: Among-population morphological variation was smaller than within-population variation, which was primarily explained by variation in axilla-groin length, number of infralabials, number of scansors on toe IV, and head-related variables such as head height and width. The population discrimination power was 32.4% and in cluster analysis, populations from the three countries tended to intermix in two major groups. Conclusion: Our results indicate that morphological differentiation among the studied populations is scarce, suggesting short history for some populations after their establishment, frequent migration of individuals among the populations, and/or local morphological differentiation in similar urban habitats. Nevertheless, we detected interesting phenetic patterns that may predict consistent linkage of particular populations that are independent of national borders. Additional sampling across the range and inclusion of genetic data could give further clue for the historical relationship among Chinese, Japanese, and Korean populations of G. japonicus.

• Journal of Ecology and Environment
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• 제43권4호
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• pp.427-437
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• 2019

Background: Climate change is believed to be continuously affecting ticks by influencing their habitat suitability. However, we attempted to model the climate change-induced impacts on future genus Rhipicephalus distribution considering the major environmental factors that would influence the tick. Therefore, 50 tick occuance points were taken to model the potential distribution using maximum entropy (MaxEnt) software and 19 climatic variables, taking into account the ability for future climatic change under representative concentration pathways (RCPs) 4.5 and 8.5, were used. Results: MaxEnt model performance was tested and found with the AUC value of 0.99 which indicates excellent goodness-of-fit and predictive accuracy. Current models predict increased temperatures, both in the mid and end terms together with possible changes of other climatic factors like precipitation which may lead to higher tick-borne disease risks associated with expansion of the range of the targeted tick distribution. Distribution maps were constructed for the current, 2050, and 2070 for the two greenhouse gas scenarios and the most dramatic scenario; RCP 8.5 produced the highest increase probable distribution range. Conclusions: The future potential distribution of the genus Rhipicephalus show potential expansion to the new areas due to the future climatic suitability increase. These results indicate that the genus population of the targeted tick could emerge in areas in which they are currently lacking; increased incidence of tick-borne diseases poses further risk which can affect cattle production and productivity, thereby affecting the livelihood of smallholding farmers. Therefore, it is recommended to implement climate change adaptation practices to minimize the impacts.

• 환경생물
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• 제27권1호
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• pp.82-87
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• 2009

우리나라의 주요 우점종인 상수리나무, 굴참나무, 신갈나무의 생태적 특성을 밝히기 위하여 식물생장에서 가장 중요하다고 판단되는 광, 토양수분, 영양소를 이들 3종의 참나무 유식물에 각각 실내에서 처리하여 그 생육반응을 관찰하고, 분석하고자 시도하였다. 상수리나무와 굴참나무는 광이 높을수록 잘 자라는 경향이 있었고, 신갈나무만이 뚜렷한 경향이 없었다. 신갈나무는 낮은 광도에서도 생육이 크게 감소하지 않았다 굴참나무와 신갈나무는 수분구배에 따라 생육의 차이가 없었고, 상수리나무만이 약간 높은 구배에서 잘 자랐을 뿐이었다. 상수리나무, 굴참나무와 신갈나무 모두는 영양소가 적을 때 잘 자랐고, 높을수록 못 자랐다. 영양소 구배에 따른 감소정도는 굴참나무, 신갈나무, 상수리나무 순으로 낮았다. 이상으로 볼 때, 신갈나무는 피음조건에, 상수리나무는 토양이 다습한 조건에 그리고 굴 참나무는 유기물이 적은 조건에서 각각 적응한 종이라고 판단된다.