• Korean Journal of Microbiology
• /
• v.54 no.1
• /
• pp.69-70
• /
• 2018

Erwinia pyrifoliae is a Gram-negative bacterium causing black shoot blight in apple and Asian pear trees. E. pyrifoliae strain EpK1/15 was isolated in 2014 from an apple twig from the Pocheon, Gyeonggi-do, South Korea. In this study, we report the draft genome sequence of E. pyrifoliae EpK1/15 using PacBio RS II platform. The draft genome is comprised of a circular chromosome with 4,027,225 bp and 53.4% G + C content and a plasmid with 48,456 bp and 50.3% G + C content. The draft genome includes 3,798 protein-coding genes, 22 rRNA genes, 77 tRNA genes, 13 non-coding RNA genes, and 231 pseudo genes.

• Journal of agriculture & life science
• /
• v.45 no.2
• /
• pp.15-20
• /
• 2011

This study was conducted to estimate the aboveground biomass and net primary production of 40 year old Pinus rigida forest in Sancheong, Gyeongnam province. The aboveground biomass was $127.7Mg\;ha^{-1}$ and $103.1Mg\;ha^{-1}$ of which were found from stem, $17.2Mg\;ha^{-1}$ from branch and $7.4Mg\;ha^{-1}$ from leaf. Biomass distribution ratio of Pinus rigida stands showed the highest in stem wood with 71.1%, followed by the branch with 13.5%, stem bark with 9.6% and lastly the leaf with 5.8%. Net primary production of aboveground biomass was $10.4Mg\;ha^{-1}$ and $3.6Mg\;ha^{-1}$ were found from stem, $2.2Mg\;ha^{-1}$ from branch, $1.3Mg\;ha^{-1}$ from twig and $2.8Mg\;ha^{-1}$ from leaf. Net primary production distribution ratio of Pinus rigida was 34.6% on stem wood, 26.9 on leaf, 21.2% on branch, 12.5% on twig and 4.8% on stem bark.

• Journal of agriculture & life science
• /
• v.45 no.6
• /
• pp.213-226
• /
• 2011

This study was performed to investigate the effect of essential oils and ethanolic extracts of approximately 650 plant species on acetylcholine esterase (AChE) enzyme activity using Ellman's colorimetric method in 96-well microplates. The results showed that the ethanolic extracts from twig of Sophora subprostrata, twig of Phellodendron amurense, seed of Corylopsis coreana, and essential oil (EO) from Citrus paradisi, Cupressus sempervirens, Ocimum basilicum, Pinus sylvestris and Rosmarinus officinalis inhibited more than 80% of AChE activity. Among these, EO from Pinus sylvestris, C. sempervirens and C paradisi exhibited higher values of AChE inhibitory activity, which were 75, 84 and 99% at a concentration of 50 ug/ml, respectively. Finally, EO from C paradisi (grapefruit, GEO) showed the highest inhibitory activity towards AChE, which showed 91% of inhibition at a concentration of 20 ug/ml. We also examined the anti-dementia effects of GEO in mouse by passive avoidance test and Morris water maze test. The model mouse (male, ICR) of dementia (negative control) was induced by administration of scopolamine (1 mg/kg body weight). The latency time of sample group administrated with GEO (100 mg/kg, p.o.) increased significantly as compared with negative control on passive avoidance test. There were significant recovery from the scopolamine-induced deficits on learning and memory in water maze test through daily administrations with GEO (100 mg/kg, p.o.). From these results, we conclude that GEO treatment might enhance the cognitive function, suggesting that the EO of C. paradis may be a potential candidate for improvement of perceptive ability and dementia.

• The Korean Journal of Ecology
• /
• v.6 no.4
• /
• pp.1-9
• /
• 1983

The observation of branching pattern on Magnolia denudata Desr. was performed from July 1982 to September 1983 and then computer simulation was carried out. Tree crown pattern depends on not genetic factors but also environmental factors and the determination of branchin pattern which characterized it appears to properly explain the relationships such as branching pattern and allocation of materials through the analysis of influence branches under several assumptions. Now that computer simulated simulated pattern was considered as the accumulation of two factors which controled the growth, it was represented as the stimulated tree which differs in branching rate that described allocation of material necessary for the growth of each branch. There was a tendency of allocation ratio of nutrients, i.e. subbranch to main branch to decrease by the passage of year. Under assumption that branch was branched when accumulated material reached 1, it was possible to represent the allocation of nutrients are residual $nutrient{\times}\frac{1}{1+F};in main; branch, ; residual; nutrient{\times}\frac{F}{1+F}$ in subbranch, A(iA, iC)+$F^(iA-1)$ in current twig. Like this, the basic minute difference of the allocation of nutrients according to the branch resulted in complicated patterns in the tree crown.

• The Plant Pathology Journal
• /
• v.17 no.5
• /
• pp.295-299
• /
• 2001

The relative density of phytoplasmas in witches'broom (WB)-infected jujube trees was investigated using compatitive polymerase chain reaction (PCR). During dormant and defoliating seasons, the densities of phytoplasmas were about the same in roots and twigs. In early growing season, the density showed the highest rates in roots, then in twigs and in petioles. however, the density was highest in petioles and the lowest in roots during actively growing season. Throughout the year, root samples did not show any serious fluctuation compared with that of t2wigs and petioles. Density was lowest during actively growing season in root samples. In contrast, petiole sample densities varied to a great extent depending on the season, very high during actively growing season, but very low during the early growing season, In twig samples, the densities were very high and almost the same in both defoliating and dormant seasons. Among the parts of the trees, phytoplsma density was the most stable in root samples throughout the year. The highest densities of phytoplasmas were about the same in all tree parts. These results suggest that the phytoplasmas may overwinter not only in roots but also in twigs, and that multiplication rate of phytoplsma becomes very high right after the early growing season.

• The Plant Pathology Journal
• /
• v.22 no.4
• /
• pp.375-380
• /
• 2006

In the survey from 1992 to 2000, twenty-eight parasitic diseases were observed in major apple producing areas in Korea. The predominant apple diseases were white rot(Botryosphaeria dothidea), Marssonina blotch(Marssonina mali), Valsa canker(Valsa ceratosperma), Alternaria leaf spot(Alternaria mali), and bitter rot(Collectotrichum gloeosporioides and C. acutatum). Apple scab that reappeared in 1990 after disappearance for 15 years was disappeared again since 1997. A viroid disease(caused by apple scar skin viroid) was newly found in this survey. The five diseases, fire blight(Erwinia amylovora), black rot(Botryosphaeria obtusa), scab(Cladosporium carpophilum), Monochaetia twig blight(Monochaetia sp.), and brown leaf spot(Hendersonia mali), which had once described in 1928 but no further reports on their occurrence, were not found in this survey. However, blossom blight(Monilinia mali), brown rot(Monilinia fructigena), and pink rot(Trichothecium roseum), which did not occur on apple after mid 1970s, were found in this survey.

• Journal of Environmental Science International
• /
• v.27 no.4
• /
• pp.275-279
• /
• 2018

Water status of intact plants has been optically estimated by measuring reflectance at the wavelengths 1,450 nm and 1,900 nm based on their signal strengths. Although another water band at 970 nm is considered to have very small signals, the band apparently lies within the detection range of inexpensive spectrometer and plain charge-coupled device (CCD) camera used in wild fire studies. However measurement of the reflectance at 970 nm has been rarely applied to estimate the water status of dead plant materials such as fallen branch, twig, and leaf. To test the possibility of applying water reflectance at 970 nm to estimate the water content (WC) in leaf litter, the reflectance in various WC values were measured in the leaf litter of three Quercus species (Q aliena, Q aliena, Q mongolica, and Quercus variabilis). The results showed that the WC in the leaf litter can be determined by reflectance water index (WI) in the three Quercus species ($WC=1,450{\times}WI-1,378.8$, r=0.865). However, there was no interaction effect in the relationship between WI and WC among the litter of the three Quercus species.

• Journal of Environmental Science International
• /
• v.7 no.3
• /
• pp.251-262
• /
• 1998

A number of illustrated floras are generally used when we want to idenufy a name of a certain tree. This method, however, has not been efficient because it has taken a great deal of time and effort for persons who do not have much knowledge on the group of the plant. In contrast to this method, the use of taxonomical keys is very efficient for finding out the group of a certain plant. But this method Is very dirtficult for non-specialists to understand the taxonomical ternunology and thus has not been of general use. In thins context, this study was conducted to present the efficient way of the group of a certain tree through the computer database by using the brief forms of plant organs. The database consists of effect fields such as form of trunk and evergreen or deciduous, types of leaf and leaf arrangement, existence of price and hair on twig, form of leaf margin, leaf form and venation, existence of hair on leaf surface and petiole, length of leaf and petiole. The 222 species of tree used for landscape architecture were sorted by items of the eight fields. As a result, the 222 species were divided into 185 groups and the one group contains 7species, 2 groups contain 3 species, 27 groups contain 2 species and 155 groups contain only one species. Therefore it is suggested that the use of computer database and illustrated floras is very easy and efficient in identifying a tree.

• Plant Disease and Agriculture
• /
• v.5 no.1
• /
• pp.34-40
• /
• 1999

The virus infection rates and disease symptoms of three major citrus viruses, citrus tristeza virus (CTV), satsuma dwarf virus (SDV), and citrus tatter leaf virus (CTLV), were investigated at 35 citrus orchards in Cheju Island from 1995. The infection rates of CTV, SDV, and CTLV were 69.8%, 8.6%, and 9.3%, respectively. However, depending on cultivars there were significant differences in the infection rates. The infection rates of CTV were highest in early satsuma mandarin (Citrusunshiu) with 80.9% and lowest in very early satsuma mandarin with 51.9%. In SDV, the highest was in very early stasuma mandarin with 23.1% and the lowest was in early satsuma mandarin with 6.3%. And the highest infection rate in very early satsuma mandarin with 17.9% and the lowest in tangors with 7.3% in CTLV. The symptoms of virus-infected citrus were very diverse; small and abnormal shape of fruits, abnormal leaves such as narrow boat and small spoon shapes of leaves, stem-pitting on the twig, bud-union crease and swelling of the graft part, reduction of the plant vigor and poor yields.

• Korean Journal of Pharmacognosy
• /
• v.39 no.3
• /
• pp.223-227
• /
• 2008

Advanced glycation end products (AGEs) contribute to the progression of micro and macrovsacular complication of diabetes and therefore present a promising target for therapeutic agents. In this study, 40 Korean herbal medicines have been investigated with an in vitro evaluation system using AGEs inhibitory activity. Of these, 21 herbal medicines $(IC_{50}<50{\mu}g/ml)$ exhibited an inhibitory activity against AGEs formation compared with anminoguanidine $(IC_{50}=72.12{\mu}g/ml)$. Particularly, 7 herbal medicines, Actinidia arguta (root and stem), Crataegus pinnatifida (twig), Camellia japonica (whole), Kalopanax pictus (bark), Lagerstroemia indica (leaf-stem), Reynoutria sachalinensis (root) showed more potent inhibitory activity (approximately 3-10 fold) than the positive control aminoguanidine.