• FLOWER RESEARCH JOURNAL
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• v.17 no.4
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• pp.231-236
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• 2009

This study was conducted to identity the effect of plant growth retardants such as paclobutrazol, ethephon, uniconazole and daminozide by drenching on growth of Datura suaveolens 'Orange Star'. Datura suaveolens 'Orange Star' treated with the growth retardants except ethephon was gradually shortened in proportion to the treated concentration of growth retardants. Especially, uniconazole treatment dramatically short ed stem height and width of plant, diminished leaf width and length and also shortened the days to flowering, and increased flowering times per year. On the contrary, ethephon treatment showed the opposite affect such as higher plant width and plant height, increased days to flowering, and decreased the number of flower times. Dwarfing by plant growth retardants in Datura suaveolens 'Orange Star' was effective in orders of uniconazole, daminozide and paclobutrazol.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.105-115
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• 2019

Saline or alkaline condition in soil inhibits growth of most crop plants and limits crop yields in many parts of the world. Augmenting an alkaline soil with alkali-tolerant bacteria capable of promoting plant growth can be a promising approach in expanding fertile agricultural land. Near-shore environments of Dokdo Island, a remote island located in the middle of the East Sea, appear to have patches of seawater-influenced haloalkaline soil that is unsupportive for growth of conventional plants. To exploit metabolic capacities of alkali-tolerant bacteria for promoting plant growth in saline or alkaline soils, we isolated of alkali-tolerant bacteria from near-shore soil samples in Dokdo and investigated properties of the isolates. Alkali-tolerant bacteria were selectively cultivated by inoculating suspended and diluted soil samples on a plate medium adjusted to pH 10. Fifty colonies were identified based on their $GTG_5$-PCR genomic fingerprints and 16S rRNA gene sequences. Most isolates were affiliated to alkali-tolerant and/or halotolerant genera or species of the phyla Firmicutes (68%), Proteobacteria (30%) and Actinobacteria (2%). Unlike the typical soil bacterial flora in the island, alkali-tolerant isolates belonged to only certain taxa of terrestrial origin under the three phyla, which have traits of plant growth promoting activities including detoxification, phytohormone production, disease/pest control, nitrogen-fixation, phosphate solubilization or siderophore production. However, Firmicutes of marine origin generally dominated the alkali-tolerant community. Results of this study suggest that haloalkaline environments like Dokdo shore soils are important sources for plant growth promoting bacteria that can be employed in bio-augmentation of vegetation-poor alkaline soils.

• Korean Journal of Medicinal Crop Science
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• v.22 no.4
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• pp.306-312
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• 2014

Endophytes are microorganisms that live in the internal tissues of plants without harming the host plants. In this symbiotic relationship, the host plants provide nutrients and shelter to the endophytes, in turn, endophytes can promote the growth of host plants and act as a biological control agents against plant pathogens. Plant-microbe interactions like this are noted for natural methods for sustainable agriculture and environmental conservation. However, in spite of the infinite potential, there are only a few reports on the endophytes present in ginseng. In this study, we isolated and identified the endophytes from Panax ginseng seeds and evaluated the biological activities (IAA production ability, nitrogen fixation ability, phosphate solubilization capacity, siderophore production ability, and antifungal activities) of the endophyte isolates. Eight different endophytes were identified by 16S rRNA sequencing. Most of the endophytes have antibiotic and plant growth promoting (PGP) activities. Particularly, PgSEB5-37E have the highest antibiotic activity, both PgSEB5-37B and PgSEB5-37H have high PGP traits such as an abilities to produce IAA, solubilize phosphate and fix nitrogen. These results indicated that the endophytes from P. ginseng seeds may have applicable value to many industries. In order to use the isolated endophytes, quantitative analysis and field tests are needed to be performed.

• Journal of the Korean Wood Science and Technology
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• v.46 no.6
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• pp.645-655
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• 2018

The use of wood waste as substrate for plant growth exemplifies a strategy for turning waste into resources. The overall objective of this research was to evaluate the effects of wood-based growing media on plant cover in a slope area. Moreover, we tried to find out what physicochemical properties affect plant cover on a slope. For treatments, we tested natural soil, soil mixed with wood-based growing medium (1:1, w/w), and wood-based growing medium by itself. Physical and chemical characteristics were evaluated after four months from the date of treatment application to the experimental slope site. Soil coverage with seedlings of Lespedeza cyrtobotrya was measured for plant growth evaluation. Physicochemical properties were altered by mixing the natural soil with wood-based growing medium. Particularly, soil moisture and organic matter contents were significantly changed in soils treated with wood-based growing medium compared to soil alone. We confirmed that plant coverage rate was high when wood-based growing medium was mixed with the natural soil. There was a significant linear relationship between moisture content and CEC (Cation Exchange Capacity) of all growth media tested and plant coverage. This result was expected, as moisture content tends to increase with organic matter content, such as in wood-based growing medium. In conclusion, the high moisture content of the wood-based growing medium was considered effective for plant growth in the experimental slope site, and this wood-based growing medium provides a means to improve the harmony between the slope and the surrounding environment.

• The Plant Pathology Journal
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• v.34 no.3
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• pp.208-217
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• 2018

In this study, samples were collected from the leaves and stems of healthy wild Pistachio trees (Pistacia atlantica L.) from various locations of Baneh and Marivan regions, Iran. In total, 61 endophytic bacteria were isolated and grouped according to phenotypic properties. Ten selected isolates from each group were further identified by partial sequencing of the 16S rRNA gene. Based on the results, isolates were identified as bacteria belonging to Pseudomonas, Stenotrophomonas, Bacillus, Pantoea and Serratia genus. The ability of these isolates was evaluated to phytohormone production such as auxin and gibberellin, siderophore production, phosphate solubilization, atmospheric nitrogen fixation, protease and hydrogen cyanide production. All strains were able to produce the plant growth hormone auxin and gibberellin in different amounts. The majority of strains were able to solubilize phosphate. The results of atmospheric nitrogen fixation ability, protease and siderophore production were varied among strains. Only Ba66 could produce a low amount of hydrogen cyanide. The results of biocontrol assay showed that Pb78 and Sp15 strains had the highest and lowest inhibition effects on bacterial plant pathogens, Pseudomonas syringae pv. syringae Pss20 and Pseudomonas tolaasii Pt18 under in vitro condition. Pb3, Pb24 and Pb71 strains significantly promote root formation on carrot slices. To our knowledge this is the first report of the isolation of endophytic bacterial strains belonging to Pantoea, Bacillus, Pseudomonas, Serratia and Stenotrophomonas genus from wild pistachio trees with plant growth promoting potential and biocontrol activity.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1349-1360
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• 2015

The rhizospheric zone abutting plant roots usually clutches a wealth of microbes. In the recent past, enormous genetic resources have been excavated with potential applications in host plant interaction and ancillary aspects. Two Pseudomonas strains were isolated and identified through 16S rRNA and rpoD sequence analyses as P. fluorescens QAU67 and P. putida QAU90. Initial biochemical characterization and their root-colonizing traits indicated their potential role in plant growth promotion. Such aerobic systems, involved in gluconic acid production and phosphate solubilization, essentially require the pyrroloquinoline quinine (PQQ)-dependent glucose dehydrogenase (GDH) in the genome. The PCR screening and amplification of GDH and PQQ and subsequent induction of mutagenesis characterized their possible role as antioxidants as well as in growth promotion, as probed in vitro in lettuce and in vivo in rice, bean, and tomato plants. The results showed significant differences (p ≤ 0.05) in parameters of plant height, fresh weight, and dry weight, etc., deciphering a clear and in fact complementary role of GDH and PQQ in plant growth promotion. Our study not only provides direct evidence of the in vivo role of GDH and PQQ in host plants but also reveals their functional inadequacy in the event of mutation at either of these loci.

• Journal of People, Plants, and Environment
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• v.24 no.5
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• pp.461-468
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• 2021

Background and objective: Particulate matter (PM) has a serious impact on health. Recently, studies are conducted to reduce PM in an environmentally friendly way using plants. This study investigated the physiological responses of plants and their ability to remove PM by continuously spraying different PM sources (loam, fly ash, carbon black) to four native plant species, such as Iris sanguinea, Pteris multifida, Vitis coignetiae, and Viburnum odoratissimum var. awabuki. Methods: The four plant species were randomly placed in four chambers, and 0.1 g of different PM was injected into each chamber twice a week. We measured chlorophyll, carotenoid, chlorophyll fluorescence (Fv/Fm), total leaf area, amount of leaf wax, PM10 (sPM10) and PM2.5 (sPM2.5) on the leaf surface, and PM10 (wPM10) and PM2.5 (wPM2.5) on the wax layer. Results: For I. sanguinea and V. coignetiae, the sources of PM did not affect the growth response. P. multifida showed high chlorophyll a, b, total chlorophyll, and carotenoid content in carbon black as well as high Fv/Fm and total leaf area, thereby proving that carbon black helped plant growth. By PM sources, sPM10 showed a significant difference in three plant species, sPM2.5 in two plant species, and wPM10 in one plant species, indicating that sPM10 was most affected by PM sources. Conclusion: Carbon black increased the leaf area by affecting the growth of P. multifida. This plant can be effectively used for PM reduction by increasing the adsorption area. I. sanguinea and V. coignetiae can be used as economical landscaping plants since they can grow regardless of PM sources.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.356-361
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• 2022

Bacillus sp. is a useful strain for agriculture because it promotes plant growth and controls plant pathogens through a variety of mechanisms. In this study, we obtained a microbial preparation with a high number of viable cells by culturing newly isolated soil bacteria on an optimized medium. Subsequently, we applied this preparation to lettuce to enhance its growth and yield. First, B. amyloliquefaciens ISP-5 was isolated from soil. Next, optimization of culture medium was carried out using 5 L scale fermenters. When culturing B. amyloliquefaciens ISP-5 on this optimized medium, the number of viable cells was approximately 1000 times higher than that obtained from culturing on the commercial medium. Afterwards, the plant growth promotion properties of the ISP-5 strain were evaluated using lettuce as a test plant. Foliar spray treatment of lettuce was carried out by inoculating half the standard concentration suspension (0.5 × 10⁷ cfu/ml). As a result, leaf width increased by 8.6% and leaf length increased by 12.9% compared to the control group. Live weight also increased by 24.2% and dry weight by 23.9%. Considering the results from field test, B. amyloliquefaciens ISP-5 showed potential as a plant growth-promoting bacteria.

• Korean Journal of Organic Agriculture
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• v.11 no.2
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• pp.103-113
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• 2003

The chemical properties of oak tree wood vinegar and the effect of wood vinegar on the tomato seedling were investigated to apply wood vinegar efficiently to the organic - and natural farming system. On the basis of the results from chemical properties of the oak tree wood vinegar, mineral nutrient contents of wood vinegar was low. Therefore, wood vinegar could not be a suitable nutrient source for the plant growth at 500∼1000 times dilution level. which commonly used in the farming, if only wood vinegar is supplied for the nutrient source for the plant growth. The application of wood vinegar increased root growth up the 500 times dilution level while decreased shoot growth. Furthermore. the anion concentrations such as nitrate and phosphate of the plant were decreased by the application of wood vinegar while cation concentrations such as K. Ca. and Mg were increased. Phenolic compounds of wood vinegar such as chlorogenic acid and ferulic acid enhanced the root growth. Interestingly the application of ferulic acid increased both root and shoot growth at the level of 10$^{-4}$ M concentration. It indicated that the effect of wood vinegar on the production of healthy plant seedling may be due to the beneficial root growth by phenolic compounds such as chlorogenic acid and/or ferulic acid of the wood vinegar. However. the effect of the wood vinegar on the plant growth could be influenced by synergism or antagonism of different phenolic compounds in wood vinegar used. In addition. drench in the soil of wood vinegar may be more beneficial compared to foliar application for the improvement of root activity and plant growth.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.4
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• pp.507-513
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• 2006

Changes of in vitro true digestibility (IVTD) of Napiergrass (Pennisetum purpureum) were determined by a filter bag system, and their relationships to chemical composition, leaf to stem ratio, plant height, geographic location, climatic factors and harvest interval were studied and used to develop prediction models for the crude protein (CP), acid-detergent fiber (ADF), and neutral-detergent fiber (NDF) contents and IVTD. Partitioning the total variance of IVTD of Napiergrass showed that 80% was attributable to the effect of harvest interval. Days of growth, plant height, leaf/stem ratio, CP, ADF and NDF of Napiergrass had highly significant relationships (p<0.01) with IVTD. The highest coefficient of correlation between the ADF, NDF, and IVTD of Napiergrass and growth degree days was obtained when the base temperature was set at $0^{\circ}C$. Growth degree days could predict ADF, NDF, and IVTD of Napiergrass more accurately than plant height, and plant height is not suitable to predict IVTD.