• The Plant Pathology Journal
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• v.38 no.3
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• pp.220-228
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• 2022

Pollen is a vector for viral transmission. Pollenmediated viruses cause serious economic losses in the fruit industry. Despite the commercial importance of pollen-associated viruses, the diversity of such viruses is yet to be fully explored. In this study, we performed metatranscriptomic analyses using RNA sequencing to investigate the viral diversity in imported apple and kiwifruit pollen. We identified 665 virus-associated contigs, which corresponded to four different virus species. We identified one virus, the apple stem grooving virus, from pear pollen and three viruses, including citrus leaf blotch virus, cucumber mosaic virus, and lychnis mottle virus in kiwifruit pollen. The assembled viral genome sequences were analyzed to determine phylogenetic relationships. These findings will expand our knowledge of the virosphere in fruit pollen and lead to appropriate management of international pollen trade. However, the pathogenic mechanisms of pollen-associated viruses in fruit trees should be further investigated.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.266-272
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• 2023

Silene fissipetala Turcz., which is native to Continental China and Taiwan, was newly found in Chungcheongnam-do, Korea. S. fissipetala is similar to the related taxa S. antirrhina L., S. armeria L., and S. koreana Kom. in that it has glutinous zones. However, S. fissipetala is distinguished from the congeneric species by the presence of laciniate at the petals. The species grows on slopes and roadsides, suggesting that it is likely to have been introduced through the installation of green sites and road construction. A precise description, photographs, voucher specimens and a key to related taxa are provided.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.20-31
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• 2012

Endophytic bacterial communities of tidal flat plants antagonistic to oomycete plant pathogens were studied by the isolation of 256 root colonizing endophytic bacteria from surface-disinfected root tissues of six plants ($Rosa$ $rugosa$, $Suaeda$ $maritima$, $Vitex$ $rotundifolia$, $Carex$ $scabrifolia$, $Glehnia$ $littoralis$ and $Elymus$ $mollis$) growing in a tidal flat area of Namhae Island, Korea. To understand the antagonistic potential, an $in$ $vitro$ antagonistic assay was performed to characterize and identify strains that were antagonistic to the oomycete plant pathogens $Phytophthora$ $capsici$ and $Pythium$ $ultimum$ from the total population. Nine percent of the total number of isolated bacteria exhibited in vitro inhibitory activity against target plant pathogenic oomycetes. Taxonomic and phylogenetic placement of the antagonistic bacteria was investigated by analysis of the 16S rRNA gene sequences. The sequence analysis classified the antagonistic strains into four major classes of the domain bacteria ($Firmicutes$, ${\alpha}-Proteobacteria$, ${\gamma}-Proteobacteria$ and $Actinomycetes$) and 10 different genera. Further production of secondary metabolites, hydrolytic enzymes and plant growth promoting traits were determined for the putative new species of antagonistic endophytic bacteria. These new strains could not be identified as known species of ${\alpha}-Proteobacteria$, and so may represent novel bacterial taxa. The unexpected high antagonistic bacterial diversity associated with the tidal flat plants may be indicative of their importance in tidal flat plants as a promising source of novel antimicrobial compounds and biocontrol agents.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.555-563
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• 2016

The morphological characteristics and genetic relationships among 32 germplasms of Zanthoxylum schinifolium and Zanthoxylum piperitum collected from two farms in Korea were investigated. The traits with the most variability were seed color, leaf size, and spine size. The intraspecific polymorphism of Z. schinifolium and Z. piperitum was 96.5% and 60.3%, respectively. The genetic diversity and Shannon’s information index values ranged from 0.11 to 0.33 and 0.19 to 0.50, with average values of 0.26 and 0.42, respectively. Two ISSR primers (UBC861 and UBC862) were able to distinguish the different species. The genetic similarity matrix (GSM) revealed variability among the accessions ranging from 0.116 to 0.816. The intraspecific GSM for Z. schinifolium and Z. piperitum was 0.177-0.780 and 0.250-0.816, respectively. The GSM findings indicate that Z. schinifolium and Z. piperitum accessions have high genetic diversity and possess germplasms qualifying as good genetic resources for cross breeding. The clustering analysis separated Z. schinifolium and Z. piperitum into independent groups, and all accessions could be classified into three categories. Z. Schinifolium var. nermis belonged to independent groups. Comparison of the clusters based on morphological analysis with those based on ISSR data resulted in an unclear pattern of division among the accessions. The study findings indicate that Z. schinifolium and Z. piperitum accessions have genetic diversity, and ISSR markers were useful for identifying Z. schinifolium and Z. piperitum.

• The Korean Journal of Ecology
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• v.19 no.1
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• pp.93-104
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• 1996

Ecological approach to conservation of Korea's National Parks (KNP) was reviewed. Four hundred twenty five reports on 15 national parks for 80 years (1915~1994) were analyzed in consideration of phytocoenotic information such as flora, plant community and landscape. Total species was recorded as 157 familles, 752 genera, and 2,369 species (64.3% of Korean flora), in which is included only 75 species of the protected plant species designated by the Ministry of EnvironMent. Occurrence patterns of plant species in national parks were quite similar to one another, but those of plant community were rather unique. Seventy-four of 97 plant communities were reported in only one of 15 national parks, which might be regarded as an endemic or local vegetetation type. These facts are far different from actual status of the KNP＇s ecosystem, which indicate that not only original data in previous reports are less informative, but also tools of investigation and description are too subjective, and thus these can never afford to monitor the ecosystem. From the correlation analysis between 10 ecological characteristics, the following results were obtained: (1) the species richness was positively associated with the area of national park, (2) the number of visitors was related to landscape diversity, (3) occurrence of the designated species was closely related to the vegetation diversity. Numerical analysis (cluster analysis and ordination) using dissimilarity ratio by ecological characteristics divided 15 national parks into 4 groups. The first group, composed of national parks of Chirisan, $S\v{o}laksan$, Sokrisan, Hallasan, $T\v{o}kyusan$, Odaesan, and Sobaeksan, is recognized as the best national parks in terms of ecological conservation values. Nevertheless, they have been faced with the threat of visitor stress. This study will contribute to the establishment of strategy for appropriate conservation and sustainable use of KNP.

• Journal of Microbiology and Biotechnology
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• v.21 no.8
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• pp.777-790
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• 2011

To elucidate the biodiversity of plant growth-promoting rhizobacteria (PGPR) in Korea, 7,638 bacteria isolated from the rhizosphere of plant species growing in many different regions were screened. A large number of PGPR were identified by testing the ability of each isolate to promote the growth of cucumber seedlings. After redundant rhizobacteria were removed via amplified rDNA restriction analysis, 90 strains were finally selected as PGPR. On the basis of 16S ribosomal RNA sequences, 68 Gram-positive (76%) and 22 Gram-negative (24%) isolates were assigned to 21 genera and 47 species. Of these genera, Bacillus (32 species) made up the largest complement, followed by Paenibacillus (19) and Pseudomonas (11). Phylogenetic analysis showed that most of the Grampositive PGPR fell into two categories: low- and high- G+C (Actinobacteria) strains. The Gram-negative PGPR were distributed in three categories: ${\alpha}$-proteobacteria, ${\beta}$- proteobacteria, and ${\gamma}$-proteobacteria. To our knowledge, this is the largest screening study designed to isolate diverse PGPR. The enlarged understanding of PGPR genetic diversity provided herein will expand the knowledge base regarding beneficial plant-microbe interactions. The outcome of this research may have a practical effect on crop production methodologies.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.6
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• pp.1-16
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• 2012

The research has analysed the targeted land situation, the composition of species, legally controlled plants, vegetation distribution, dominance, species diversity, and the similarity to evaluate the plant characterization of the eco forest in Jangsan, Busan. The results of the research is as following. The number of the plants that belongs to the area is 63 families, 126 genuses, and 163 species. Among them the fern plants : 4 families, 5 genuses, 5 species, and the egg species : 5 families, 8 species, 10 species, and angiospermae : 54 families, 113 genuses, 148 species have been checked. Monocotyledoneae of angiospermae : 7 families, 20 genuses, 22 species (13.5%) and dicotyledoneae : 47 families, 93 genuses, 126 species (77.3%) have been totally checked. The endangered wildlife species by the standard of the Ministry of Environment and the rare plants by the standard of IUCN evaluation realesed by the Bureau of Forest and National Plant Institution has never been checked but one species of Weigela subsessilis has been checked as an approving plant in being delivered abroad, the 8 imported plant by the standard of National Plant Institution checked, some disturbing ecosystem plants released by the Ministry of Environment (2009) not emerged. The succession into the oak trees is occurring to the biodiversity of the researched area, the number of species and their species diversity.

• The Plant Pathology Journal
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• v.33 no.3
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• pp.296-306
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• 2017

Sugarcane mosaic virus (SCMV) is one of the most damaging viruses infecting sugarcane, maize and some other graminaceous species around the world. To investigate the genetic diversity of SCMV in Iran, the coat protein (CP) gene sequences of 23 SCMV isolates from different hosts were determined. The nucleotide sequence identity among Iranian isolates was more than 96%. They shared nucleotide identities of 75.5-99.9% with those of other SCMV isolates available in GenBank, the highest with the Egyptian isolate EGY7-1 (97.5-99.9%). The results of phylogenetic analysis suggested five divergent evolutionary lineages that did not completely reflect the geographical origin or host plant of the isolates. Population genetic analysis revealed greater between-group than within-group evolutionary divergence values, further supporting the results of the phylogenetic analysis. Our results indicated that natural selection might have contributed to the evolution of isolates belonging to the five identified SCMV groups, with infrequent genetic exchanges occurring between them. Phylogenetic analyses and the estimation of genetic distance indicated that Iranian isolates have low genetic diversity. No recombination was found in the CP cistron of Iranian isolates and the CP gene was under negative selection. These findings provide a comprehensive analysis of the population structure and driving forces for the evolution of SCMV with implications for global exchange of sugarcane germplasm. Gene flow, selection and somehow homologous recombination were found to be the important evolutionary factors shaping the genetic structure of SCMV populations.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.257-262
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• 2008

Genetic diversity of cultivated wheat is narrowing down and is increasingly becoming non-complacent in tackling new pathogenic races and adverse environmental situations. Wild relatives of wheat are rich repositories of beneficial genes that are capable of defying adverse situations. However, these wild species are not readily crossable with cultivated ones. The present study attempted to cross three wild wheat species as females with three cultivated species of varying ploidy to understand the intricate behaviour of hybrids in relation to cytology, morphology, and molecular recombination. Post-fertilization barriers caused hybrid recovery in wild species in contrast to cultivated species. Triticum monococcum did not produce hybrids in any of the crosses. Various degrees of chromosome anomalies and hybrid sterility were seen with hybrids of T. timopheevi and T. sphaerococcum. Cytoplasmic factors were suspected to add more to the abnormality. G genome from T. timopheevi could enhance more pairing between Band D of cultivated species. Precocity of certain chromosomes in laggard formation was evident, pointing towards evolutionary self balance of the genomes which prevented homeologous pairing. They are eliminated in hybrids. Molecular diversity clearly corroborated with genetic proximity of the species, which distinguished themselves by maintaining the genome homeology.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.04a
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• pp.220-221
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• 2005