• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.303-309
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• 2013

This study was performed to clarify the effect of medium compositions and plant growth regulators on the shoot, root formation and growth of 'Jarang' grape for mass propagation of virus-free plant. The formation and growth of shoot were considerably favorable in half-concentration of MS medium. However, the formation of adventitious root per explants (avg. 2.1) was effective in higher concentration (two times) of MS medium. For sucrose concentration, 1% for the shoot formation, 3% for the adventitious root formation and 1% for the growth were observed as yield significant results. With the addition of 0.05% of activated carbon, the shoot growth was improved, and it was effective for the adventitious root formation and growth as well. A pH of 6.8 in the medium was the most suitable for mass propagation; the results showed significant enhancement in the number of nodes and the length of the shoot, 3.9 and 1.3 cm, respectively. The shoot growth was the most vigorous in BA 1.0 mg/L due to the impact of the growth regulator on the mass propagation in it. Consequently, 16.9 shoots per explant were formed in NAA 1.0 mg/L so good results were obtained.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.266-271
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• 2011

Physicochemical characteristics and heavy metal content of soils located along the drainage way of an abandoned mine at Busan, Korea ($35^{\circ}31'N$, $129^{\circ}22'E$) (contaminated soil; CS) and uncontaminated soils (50-70 m apart from the drainage way) (NS) were examined. Growth of tomato plants (Solanum lycopersicom cv. Rutgers) in CS and NS, development of the root-knot nematode (Meloidogyne incognita) as root-knot gall formation on tomato plants, and non-parasitic nematode populations in soil were also examined. Growth of tomato plants, root-knot gall formation, and non-parasitic nematode populations were significantly reduced in CS with higher As content, lower pH, higher electrical conductivity (EC), and lower available phosphate (av. $P_2O_5$) than in NS. None of the other physicochemical characters examined differed significantly between CS and NS (low and no significance) and were above or below the critical levels detrimental to plant growth and nematode development, suggesting that As may be the primary hazardous heavy metal in CS. The toxicity of As might be enhanced at low pH in CS because exchangeable forms of some heavy metals increase with the decrease of soil pH. The heavy metals, especially As, may have contributed to increasing EC and decreasing av. $P_2O_5$. Therefore, the effects of mine drainage contamination from the abandoned mine were derived primarily from contamination by heavy metals such as As. These may have been enhanced in toxicity (solubility) by the lowered pH, increased soil salinity (EC) and decreased av. $P_2O_5$. Our results suggest synergistic adverse effects on the plant and the nematode by decreasing osmotic potential and nutrient availability.

• Journal of Sericultural and Entomological Science
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• v.33 no.2
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• pp.68-71
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• 1991

Mulberry cuttings from shoots of Shinkwangppong(Morus bombycis koidz.) had been callused in vermiculite separately at 15, 20, 25 and 30$^{\circ}C$ for 15 days before transplanting them in greenhouse to make clear the effect of temperature on root formation and growth is as follow. The buds of cuttings started sprouting in 4 and 6 days of callusing at 30 and 25$^{\circ}C$, respectively, reaching 100% budding in 10 and 15 days of callusing. Budding was delayed, however, at low temperature, showing 86% and 92% at 15 and 20$^{\circ}C$, respectively, in 15 days. Rooting from the cuttings was also accelerated at high temperature, showing 97-100% rooting at 25$^{\circ}C$ and 30$^{\circ}C$, in 15 days of callusing but no more than 93% at low temperature even in 35 days. Although high temperature increased root number and length after 15 days in callusing, no differences showed in the number and the weight at more than 20$^{\circ}C$ in 35 days of cuttings.

• Korean Journal of Pharmacognosy
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• v.1 no.3
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• pp.81-92
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• 1970

So far, the cultivated peony is known to be originated from an indigenous species, Paeonia albiflora $P_{ALLAS}$ var. trichocarpa $B_{UNGE}$ (PAT). In this study, these two species were morphologically examined in the external and internal feature and in the pattern of callus formation by tissue culture. Also, they were compared with another indigenous species, P. japonica $M_{IYABE}$ et $T_{AKEDA}$ var. pilosa $N_{AKAI}$ (PJ), which were regarded as being scarcely related to them. The root of the cultivated peony is massive consisting with several storage roots, each of them is a hypotrophic and fusiform. The root of PAT consists of several storage roots, each of them is branching and slender. And the storage root of PJ is short, bended buried horizontally, protruding a number of corpulent lateral root. The secondary xylem of the cultivated peony is small clusters of vessels and xylem fibres are arranged in scalariform and among these cluster, single vessel is joined, but that of PAT is small clusters of vessels are arranged in separate scalariform but are not connected with each other and that of PJ is vessels and xylem fibers are grouped together in elongated clusters that radiate outward from the center. Protoxylem of the cultivated peony is surrounded by four large metaxylem, but that of PAT and PJ by seven. On the other hand, the callus formation patterns of these peonies were different; the cultivated peony callus is formed in an orderly fashion by the mammalate meristematic cell groups, PAT callus is in disorder by the meristematic cells arranged in linear, and PJ callus is in order by the meristematic cells arranged in linear. By the comparison of three different plants in the anatomical appearance and the callus formation pattern, it is evident that the cultivated peony is not derived from PAT.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.123-135
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• 2023

Previously, Pseudomonas plecoglossicida YJR13 and Pseudomonas putida YJR92 from a sequential screening procedure were proven to effectively control Phytophthora blight caused by Phytophthora capsici. In this study, we further investigated the anti-oomycete activities of these strains against mycelial growth, zoospore germination, and germ tube elongation of P. capsici. We also investigated root colonization ability of the bacterial strains in square dishes, including cell motility (swimming and swarming motilities) and biofilm formation. Both strains significantly inhibited mycelial growth in liquid and solid V8 juice media and M9 minimal media, zoospore germination, and germ tube elongation compared with Bacillus vallismortis EXTN-1 (positive biocontrol strain), Sphingomonas aquatilis KU408 (negative biocontrol strain), and MgSO₄ solution (untreated control). In diluted (nutrient-deficient) V₈ juice broth, the tested strain populations were maintained at >10⁸ cells/ml, simultaneously providing mycelial inhibitory activity. Additionally, these strains colonized pepper roots at a 10⁶ cells/ml concentration for 7 days. The root colonization of the strains was supported by strong swimming and swarming activities, biofilm formation, and chemotactic activity towards exudate components (amino acids, organic acids, and sugars) of pepper roots. Collectively, these results suggest that strains YJR13 and YJR92 can effectively suppress Phytophthora blight of pepper through direct anti-oomycete activities against mycelial growth, zoospore germination and germ tube elongation. Bacterial colonization of pepper roots may be mediated by cell motility and biofilm formation together with chemotaxis to root exudates.

• Korean Journal of Plant Resources
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• v.37 no.1
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• pp.11-21
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• 2024

In this study, as a result of exploring the physiological activity of plants useful for agriculture on various plant resources, it was possible to confirm an activity similar to auxin that promotes plant rooting in methanol extract of Cinnamon Bark (cortex of Cinnamomum cassia J.Presl). After separating the active body by applying column chromatography and HPLC to the CHCl3 active fraction obtained by solvent extraction for each polarity from the methanol extract of cinnamon bark, cinnamyl alcohol was identified through GC/MS analysis. By bioassay using cinnamyl alcohol standard and the active fraction separated and purified from the methanol extract of cinnamon bark, the rooting rate of mung bean seedlings of the cinnamyl alcohol standard was 290% compared with the untreated control at 134.2 ㎍/mL concentration, and the adventitious root formation activity similar to the rooting rate (268.6%; 100 ㎍/mL) of the active fraction was shown. In conclusion, it is believed that cinnamyl alcohol contained in methanol extract of Cinnamon Bark is the main compound that induces adventitious root formation in mung bean.

• Journal of Oral Medicine and Pain
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• v.6 no.1
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• pp.23-34
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• 1981

In order to evaluate the correlation of age with development stage on permanent lower posterior teeth. the author exmined the roentgeregrams in standard films taken by intraoral technic and analysed the development phases of 1358 teeth of 500 males ranging from 9 to 15 years. The development was divided into 7 phases : Crown complete (Cr. C.). Root length 1/4(R. 1/4) Root length /2 (R. 1/2) Apical closure complete (A.C) The obtained results were as follows : 1. The formation of roots in full length on posterior teeth was complete as follow : a. Roots of 1st premolar : 12.72 years b. Roots of 2nd premolar : 12.94 years c. Meral Roots of 2nd molar : 13.38 years d. Distal Roots of 2nd molar : 13.46 years 2. The formation of apical forman of premolar was closured as follows : a. Apical foramen of root of 1st premolar : 13.64 years b. Apical foramen of root of 2nd premolar : 13.93 years 3. As a general rule. the mesial roots of second molar were developed earlier than distal roots of second molar. 4. In the correlation of age with the development stage, the regression equations. the correlation coefficents. and the sample numbers were “Y = 0.8370x + 10.2160, r = 0.71(p<0.01), n = 318”on lower first premolar, “Y = 0.6984x + 10.2148, r = 0.71(p<0.01), n = 385”on lower second premolar, “Y = 0.8810x + 10.2040, r = 0.65(p<0.01), n = 344”on mesial Root of lower second molar, and “Y = 0.7310x + 10.7940, r = 0.66(p<0.01), n = 311”on Distal Root of lower second molar respectively.

• Journal of Microbiology and Biotechnology
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• v.34 no.3
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• pp.570-579
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• 2024

Root-nodule nitrogen-fixing bacteria are known for being specific to particular legumes. This study isolated the endophytic root-nodule bacteria from the nodules of legumes and examined them to determine whether they could be used to promote the formation of nodules in other legumes. Forty-six isolates were collected from five leguminous plants and screened for housekeeping (16S rRNA), nitrogen fixation (nifH), and nodulation (nodC) genes. Based on the 16S rRNA gene sequencing and phylogenetic analysis, the bacterial isolates WC15, WC16, WC24, and GM5 were identified as Rhizobium, Sphingomonas, Methylobacterium, and Bradyrhizobium, respectively. The four isolates were found to have the nifH gene, and the study confirmed that one isolate (GM5) had both the nifH and nodC genes. The Salkowski method was used to measure the isolated bacteria for their capacity to produce phytohormone indole acetic acid (IAA). Additional experiments were performed to examine the effect of the isolated bacteria on root morphology and nodulation. Among the four tested isolates, both WC24 and GM5 induced nodulation in Glycine max. The gene expression studies revealed that GM5 had a higher expression of the nifH gene. The existence and expression of the nitrogen-fixing genes implied that the tested strain had the ability to fix the atmospheric nitrogen. These findings demonstrated that a nitrogen-fixing bacterium, Methylobacterium (WC24), isolated from a Trifolium repens, induced the formation of root nodules in non-host leguminous plants (Glycine max). This suggested the potential application of these rhizobia as biofertilizer. Further studies are required to verify the N₂-fixing efficiency of the isolates.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.170-173
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• 2009

Leaf and petiole explants of Pulsatilla koreana NAKAI were cultured on MS medium supplemented with various concentrations of zeatin, kinetin or BAP combined with 0.05 mg/L IAA. After 6 weeks of culture, effects of cytokinin on adventitious shoot formation from explants were investigated. The highest frequency of shoot formation was obtained when petiole explants were cultured on medium with 0.5 mg/L zeatin and 0.05 mg/L IAA. Regenerated shoot were transferred on to root induction medium. The best root formation was observed at 1/2 MS medium with 1.5 mg/L NAA. Rooted plantlets were transplanted to a mixture of perlit and soil (1:3), where they were successfully acclimatized.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.449-459
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• 1989