• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.2
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• pp.115-123
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• 2022

This study was performed to determine carbon (C) storage of urban parks [Hadae park (established year: 1977), Songlim park (established year: 1990), Pyeonggeo park (1992), Chojeon park (2005)] in Jinju-si, Gyeongsangnam-do. The soil at 0-30 cm depth was collected to measure soil C concentration. Bulk density in all soil depths was not significantly different among the four parks, whereas coarse fragments (>2 mm) were significantly higher in the Chojeon park than in the Pyeonggeo park. Soil pH and electrical conductivity were highest in Chojeon park among four parks. Soil C concentrations in all soil depths were significantly higher in the Hadae park established in 19 77 compared with the other parks established since 1990. Mean soil C concentration at 0-30 cm was the highest in the Hadae park (1.04%), followed by the Chojeon park (0.87%), the Songlim park (0.75%), and the Pyeonggeo park (0.57%). Soil C storage at 0-10 cm was not significantly different among the four urban parks, whereas soil C storage at 10-20 cm and 20-30 cm was higher in the Hadae parks than in the other parks. Total soil C storage was significantly higher in the Hadae park (28,425 kg C ha^-1) than in the Pyeonggeo park (15,622 kg C ha^-1). Mean soil C concentration and C storage were positively correlated with silt content and negatively correlated with sand content. The results suggest that soil C storage of urban parks in Jinju-si might be related to the established period of parks and silt contents.

• The Korean Journal of Ecology
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• v.4 no.1_2
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• pp.33-37
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• 1981

This study was carried out to investigate the changes of flower properties due to decomposition in the course of time and results obtained are as follows; 1. The flower shape of Salix babylonica changed so rapid that it was difficult to recognize fragments after 40 days. 2. Total weight decreased by 50% after about 40 days. Loss on ignition changed rapidly for 40 days and then steadily. 3. Remaining carbon content decreased by a half only for first 20 days, then did steadily. 4. The content of phosphorus and total nitrogen slowly during the early period and then rapidly. 5. Above phenomena are supposed to be responisble for water content, nitrogen, and phosphorus.

• Journal of the Korean Wood Science and Technology
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• v.50 no.6
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• pp.490-498
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• 2022

The current study aimed to verify the image segmentation ability of rays in tangential thin sections of conifers using artificial intelligence technology. The applied model was Mask region-based convolutional neural network (Mask R-CNN) and softwoods (viz. Picea jezoensis, Larix gmelinii, Abies nephrolepis, Abies koreana, Ginkgo biloba, Taxus cuspidata, Cryptomeria japonica, Cedrus deodara, Pinus koraiensis) were selected for the study. To take digital pictures, thin sections of thickness 10-15 ㎛ were cut using a microtome, and then stained using a 1:1 mixture of 0.5% astra blue and 1% safranin. In the digital images, rays were selected as detection objects, and Computer Vision Annotation Tool was used to annotate the rays in the training images taken from the tangential sections of the woods. The performance of the Mask R-CNN applied to select rays was as high as 0.837 mean average precision and saving the time more than half of that required for Ground Truth. During the image analysis process, however, division of the rays into two or more rays occurred. This caused some errors in the measurement of the ray height. To improve the image processing algorithms, further work on combining the fragments of a ray into one ray segment, and increasing the precision of the boundary between rays and the neighboring tissues is required.

• The Plant Pathology Journal
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• v.36 no.5
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• pp.459-467
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• 2020

Areca palm yellow leaf (AYL) disease caused by the 16SrI group phytoplasma is a serious threat to the development of the Areca palm industry in China. The 16S rRNA gene sequence was utilized to establish a rapid and efficient detection system efficient for the 16SrI-B subgroup AYL phytoplasma in China by loop-mediated isothermal amplification (LAMP). The results showed that two sets of LAMP detection primers, 16SrDNA-2 and 16SrDNA-3, were efficient for 16SrI-B subgroup AYL phytoplasma in China, with positive results appearing under reaction conditions of 64℃ for 40 min. The lowest detection limit for the two LAMP detection assays was the same at 200 ag/μl, namely approximately 53 copies/μl of the target fragments. Phytoplasma was detected in all AYL disease samples from Baoting, Tunchang, and Wanning counties in Hainan province using the two sets of LAMP primers 16SrDNA-2 and 16SrDNA-3, whereas no phytoplasma was detected in the negative control. The LAMP method established in this study with comparatively high sensitivity and stability, provides reliable results that could be visually detected, making it suitable for application and research in rapid diagnosis of AYL disease, detection of seedlings with the pathogen and breeding of disease-resistant Areca palm varieties.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.2
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• pp.169-178
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• 2014

In this study, we investigated genetic diversity of 22 microsporidian isolates infecting tropical tasar silkworm, Antheraea mylitta collected from various geographical forest locations in the state of Jharkhand, India, using polymerase chain reaction (PCR)-based marker assay: random amplified polymorphic DNA (RAPD). A type species, NIK-1s_mys was used as control for comparison. The shape of mature microsporidians was found to be oval to elongate, measuring 3.80 to $5.10{\mu}m$ in length and 2.56 to $3.30{\mu}m$ in width. Of the 20 RAPD primers screened, 16 primers generated reproducible profiles with 298 polymorphic fragments displaying high degree of polymorphism (97%). A total of 14 RAPD primers produced 45 unique putative genetic markers, which were used to differentiate the microsporidians. Calculation of genetic distance coefficients based on dice coefficient method and clustering with un-weighted pair group method using arithmetic average (UPGMA) analysis was conducted to unravel the genetic diversity of microsporidians infecting tasar silkworm. The similarity coefficients varied from 0.059 to 0.980. UPGMA analysis generated a dendrogram with four microsporidian groups, which appear to be different from each other as well as from NIK-1s_mys. Two-dimensional distribution based on Euclidean distance matrix also revealed considerable variability among different microsporidians identified from the tasar silkworms. Clustering of few microsporidian isolates was in accordance with the geographic origin. The results indicate that the RAPD profiles and specific/unique genetic markers can be used for differentiating as well as to identify different microsporidians with considerable accuracy.

• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.40-56
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• 2023

Tree species within the Populus genus grow rapidly and have an excellent capacity to absorb carbon, conferring substantial ability to effective purify the environment. Poplar breeding can be achieved rapidly and efficiently if a genetic linkage map is constructed and quantitative trait loci (QTLs) are identified. Here, a high-density genetic linkage map was constructed for the control pollinated progeny using the genotyping-by-sequencing (GBS) technique, which is a next-generation sequencing method. A search was also performed for the genes associated with quantitative traits located in the genetic linkage map by examining the variables of height and diameter at root collar, and resilience to insect damage. The height and diameter at root collar were measured directly, while the ability to recover from insect damage was scored in a 4-year-old breeding population of aspen hybrids (Odae19 × Bonghyeon4 F1) established in the research forest of Seoul National University. After DNA extraction, paternity was confirmed using five microsatellite markers, and only the individuals for which paternity was confirmed were used for the analysis. The DNA was cut using restriction enzymes and the obtained DNA fragments were prepared using a GBS library and sequenced. The analyzed results were sorted using Populus trichocarpa as a reference genome. Overall, 58,040 aligned single-nucleotide polymorphism (SNP) markers were identified, 17,755 of which were used for mapping genetic linkages. The genetic linkage map was divided into 19 linkage groups, with a total length of 2,129.54 cM. The analysis failed to identify any growth-related QTLs, but a gene assumed to be related to recovery from insect damage was identified on linkage group (chromosome) 4 through genome-wide association study.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.42-46
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• 1998

Polymerase chain reaction (PCR) and Southern hybridization analyses were carried out to identify clones of silk worm thorn (Cudraria tricuspidata) and Rose of sharon (Hibiscus syriacus) which look like one tree with two ar three, branches or two or three different trees. For PCR five different PCR primers $(17{\sim}24\;nucleotides)$ are derived from CaMV 35S promoter, nopaline synthase terminator and coding region of thylakoid membrane protein gene. In the case of silk worm thorn, about 500 bp of PCR product was produced from DNAs of one tree or branch in the presence of 35S primer alone. Southern hybridization analysis of genomic DNAs hybridized with $^{32}P$ labeled PCR product showed that the same size of DNA fragments were hybridized with different intensities. In addition, PCR analyses using 20 different primers of OPERON 10-mer kits showed that only OPA01 primer produced PCR products of different size. These results indicate that two different trees of silk worm thorn combined to one tree. In the case of the Rose of Sharon, the same size of PCR products were produced from three different samples but Southern hybridization with the above PCR product as a probe did not show any hybridized bands. PCR analyses in the presence of OPERON 10-mers showed OPA04 and OPA13 produced different products including same sizes of products. These, results indicate that three different trees of the Rose of Sharon seem to be derived from the tree.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.191-197
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• 2013

Two medium-leaf ecotypes (CY6069, CY6097) belonging to one species (Zoysia japonica) of Korean lawngrasses were selected in sod production fields in Jang Seong, Korea. They were reported to have distinct morphological and growth rate characteristics different from the preferred medium-leaf type zoysiagrass in Korea. This study was conducted to define further the genotypic difference at the molecular level and to develop DNA marker based on the specific DNA fragment. Polymorphic DNA fragments were first explored by using randomly amplified polymorphic DNA (RAPD) primers, which were then converted into PCR-based sequence characterized amplified region (SCAR) markers. The CY6069-specific primer set amplified about 550 bp successfully, while the CY6097 marker produced the expected 690 bp band, by which those markers were nominated by CY6069_550 and CY6069_690 SCARs, respectively. Together with the reported morphological and other phenotypic features, the SCAR markers confirmed in this study will be useful to identify those medium-leaf zoysiagrass genotypes when they are cultivated with other vegetatively propagated warm-season turfgrasses in sod farms.