• Genomics & Informatics
• /
• v.11 no.4
• /
• pp.272-276
• /
• 2013

Sequence analysis of the 16S rRNA gene has been widely used for the classification of microorganisms. However, we have been unable to clearly identify five Flavobacterium species isolated from a freshwater by using the gene as a single marker, because the evolutionary history is incomplete and the pace of DNA substitutions is relatively rapid in the bacteria. In this study, we tried to classify Flavobacterium species through multilocus sequence analysis (MLSA), which is a practical and reliable technique for the identification or classification of bacteria. The five Flavobacterium species isolated from freshwater and 37 other strains were classified based on six housekeeping genes: gyrB, dnaK, tuf, murG, atpA, and glyA. The genes were amplified by PCR and subjected to DNA sequencing. Based on the combined DNA sequence (4,412 bp) of the six housekeeping genes, we analyzed the phylogenetic relationship among the Flavobacterium species. The results indicated that MLSA, based on the six housekeeping genes, is a trustworthy method for the identification of closely related Flavobacterium species.

• Journal of Plant Biology
• /
• v.13 no.2
• /
• pp.11-14
• /
• 1970

Identification and observations of leucine aminopeptidase (LAP) and multiple molecular forms of the enzyme, isozymes, were made with a technique of starch-gel electrophoresis for various legume pollen. Plants tested other than Leguminosae demonstrated either no indication of the presence or at least tract of enzymes and the isozymes, although all legume pollen tested showed strong LAP patterns. The electrophoretic patterns of LAP failed to be shown if the extracts were heated or otherwise denatured. Extent of zymogrammatic appearance of LAP and the isozymes were characteristic of a species.

• Journal of Biosystems Engineering
• /
• v.24 no.1
• /
• pp.59-66
• /
• 1999

Weed identification is important for precision farming. A machine vision system was applied to detect weeds. Shape features were analyzed with the binary images obtained from color images of radish, purslane, goosefoot, and crabgrass. Features studied were aspect, roundness, compactness, elongation, PTB, LTP, LTW, and PTAL of each plant. Discriminant analysis was used to classify plant species. The best shape features that distinguished crabgrass were LTP and LTW which distinguished the crabgrass from the others with 100%. Two dimensional discrimination by using LTP and PTB appeared to be effective for distinguishing radish, purslane, and goosefoot.

• Plant Biotechnology Reports
• /
• v.2 no.2
• /
• pp.93-112
• /
• 2008

Medicinal and aromatic plants (MAPs) are important sources for plant secondary metabolites, which are important for human healthcare. Improvement of the yield and quality of these natural plant products through conventional breeding is still a challenge. However, recent advances in plant genomics research has generated knowledge leading to a better understanding of the complex genetics and biochemistry involved in biosynthesis of these plant secondary metabolites. This genomics research also concerned identification and isolation of genes involved in different steps of a number of metabolic pathways. Progress has also been made in the development of functional genomics resources (EST databases and micro-arrays) in several medicinal plant species, which offer new opportunities for improvement of genotypes using perfect markers or genetic transformation. This review article presents an overview of the recent developments and future possibilities in genetics and genomics of MAP species including use of transgenic approach for their improvement.

• The Plant Pathology Journal
• /
• v.24 no.2
• /
• pp.159-163
• /
• 2008

Accurate identification of pine wood nematode, Bursaphelenchus xylophilus is a prerequisite to diagnose the pine wilt disease. However, a fungivorous nematode, B. mucronatus is highly similar to B. xylophilus and it is difficult to differentiate these two species by morphological features. A molecular diagnosis method, ITSRFLP was applied for the identification of B. xylophilus and B. mucronatus from Korea. Genomic DNA was extracted from a single individual nematode and ITS DNA was amplified by PCR. The size of PCR product was approximately 900bp and the sequence data were obtained after cloning. Amplified ITS was digested by 5 different restriction enzymes (Rsa I, Hae III, Msp I, Hinf I, and Alu I) and provided a discriminatory profile for B. xylophilus and B. mucronatus. Besides, B. mucro- natus was determined to have 2 different genotypes, East Asian type and European type also clearly separated by Rsa I and Hae III digestion. European type of B. mucronatus is recently collected from Pinus koraiensis and has not been reported before. ITS sequnce data were analyzed by Restriction Mapper program and the result supported ITS-RFLP pattern. These data indicated that PCRRFLP method is an accurate and simple way for identification of Bursaphelenchus species.

• Journal of the Korean Wood Science and Technology
• /
• v.46 no.4
• /
• pp.402-414
• /
• 2018

Species identification of wood provides important information for archaeology, restoration of cultural assets, preventing illegal logging, and more. Wood species are usually identified based on their anatomical features with the use of a microscope. However, this method may not be able to distinguish between anatomically similar species or subspecies. To overcome this problem, wood species need to be identified at the molecular level using DNA sequencing. However, unlike living plant cells, wood is difficult to pulverize using a mortar, and DNA extraction from dried wood is challenging. To solve these problems, we propose a pretreatment method in which wood is pulverized using 60-grit sandpaper and hydrated with water for 2 days. Using this method, we were able to stably amplify the rpoB gene from the extracted DNA of Pinus rigida. In addition, sequence analysis of the rpoB gene revealed six single nucleotide polymorphisms (SNPs), which classified the rpoB sequences in the genus Pinus into five groups. Our data indicate that although these SNPs were not suitable for species identification, they can potentially be used to determine the origin of different wood subspecies or individual samples of wood.

• The Korean Journal of Mycology
• /
• v.47 no.2
• /
• pp.95-104
• /
• 2019

The genus Ochrolechia is a widespread, lichen genus in Korea. Despite being common, little is known about the species diversity and geographical distribution of Ochrolechia. In this study, we detailed the identification procedure of the genus Ochrolechia in a Korean collection and provided the description of each species. Using 104 specimens collected from 2003 to 2017, we identified four species of the genus Ochrolechia via morphological and/or molecular phylogenetic analysis: O. parellula, O. trochophora, O. yasudae and O. akagiensis. Among them, O. akagiensis had not been previously reported in Korea. Moreover, the species identified as O. frigida and O. tartarea in past studies were corrected as O. yasudae and O. parellula, respectively, based on morphological and/or molecular evidence. Phylogenetic analysis using the internal transcribed spacer regions including 5.8S rRNA gene showed that the four species separated clearly, indicating that the morphological identification corresponds to the phylogenetic identification. We provide a taxonomic key for the four species of the genus Ochrolechia.

• The Plant Pathology Journal
• /
• v.28 no.3
• /
• pp.239-247
• /
• 2012

Phytoplasmas have been associated with more than 46 plant species in Korea. Several vegetables, ornamentals, fruit trees and other crop species are affected by phytoplasma diseases. Six 16Sr groups of phytoplasmas have been identified and these phytoplasmas are associated with 63 phytoplasma diseases. Aster yellows phytoplasmas are the most prevalent group and has been associated with more than 25 diseases in Korea. Jujube witches' broom, paulownia witches' broom and mulberry dwarf diseases cause economic losses to host trees throughout the country. So far, Korean phytoplasmas belong to six species of 'Candidatus Phytoplasma'; 'Ca. P. asteris', 'Ca. P. pruni$^*$', 'Ca. P. ziziphi', 'Ca. P. trifolii', 'Ca. P. solani$^*$' and 'Ca. P. castaneae'. The diseases are distributed throughout the country and most of them were observed in Gyeongbuk and Chonbuk provinces. At least four insect vectors; Cyrtopeltis tenuis, Hishimonus sellatus, Macrosteles striifrons and Ophiola flavopicta have been identified for phytoplasma transmission.

• Journal of Species Research
• /
• v.12 no.4
• /
• pp.299-306
• /
• 2023

A northern lineage plant, Stellaria filicaulis (Caryophyllaceae), was newly found in Yeoncheon-gun, Gyeonggi-do of South Korea. This species is distributed in China, Japan, Korea, Mongolia, and Russia. On the Korean Peninsula, St. filicaulis, however, has been known to grow in North Korea. Species identification was confirmed using morphological characteristics and DNA sequence data, while comparing with materials obtained from herbarium specimens. Stellaria filicaulis is distinguished from St. longifolia by having smooth surface of stem, petals about twice longer than sepals. On the neighbor-joining tree, St. filicaulis formed a clade, and the species is closely related to St. longifolia of the Parviflorae clade. Details of the morphological characters, the type specimens, voucher specimens data, and photographs of St. filicaulis in South Korea are presented. In addition, it is likely that a new habitat will be found by plant biodiversity field surveys through the middle part of the Korean Peninsula. Further research is needed to determine its population size, distribution, and threats, as well as identify appropriate locations for conservation collection of germplasm.

• 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.