• The Plant Pathology Journal
• /
• v.18 no.3
• /
• pp.109-114
• /
• 2002

To evaluate the phylogenetic and taxonomic status of the phytoplasmas associated with water dropwort (Oenanthe javanica DC) disease in Korea and Japan, their 16S rDNA was analyzed. DNAs extracted from water dropworts collected in Korea (Kyongnam province) and Japan (Chiba prefecture) affected by witches' broom and yellows were subjected to PCR using phytoplasma-specific primers, which amplified a 1.4-kbp fragment that included the 16S rDNA. Phytoplasmas were characterized by RFLP analysis using AluI, HaeIII, HhaI, KpnI, MseI, and RsaI restriction enzymes and by sequence analysis of the PCR products. The mater dropwort witches'broom (WDWB) and water dropwort yellows (WDY) 16S rDNA sequences were identical and closely related to onion yellows (OY, 99.9% identity), which belong to the aster yellows (AY) 16S-subgroup. However, the KpnI RFLP analyses clearly distinguished the WDY and WDWB phytoplasmas from the OY phytoplasma. The phylogenetic analysis based on 16S rDNA showed that WDWE and WDY phytoplasmas are members of a relatively homogeneous group that evolved from a common ancestor.

• The Plant Pathology Journal
• /
• v.28 no.4
• /
• pp.381-389
• /
• 2012

Molecular characterization of Cucumber mosaic virus (CMV) was done by using samples from tomato and cucurbitaceous plants collected from different locations in the northwest region of Iran. After screening by enzyme-linked immunosorbent assay, 91 CMV-infected samples were identified. Biological properties of eight representative isolates were compared with each other revealing two distinct phenotypes on squash and tomato plants. Phylogenetic analyses based on nucleotide sequences of the coat protein (CP), movement protein (MP) and 2b of the new isolates, together with that of previously reported isolates, led to the placement of the Iranian isolates in subgroups IA and IB according to CP and MP genes, but in subgroup IA according to the 2b gene. These data suggest that reassortment may have been a major event in the evolution of CMV in Iran, and that the Iranian isolates are derived from a common recent ancestor that had passed through a bottleneck event.

• Journal of Crop Science and Biotechnology
• /
• v.10 no.1
• /
• pp.27-32
• /
• 2007

RAPD, Inter-SSR, and AFLP markers were used to assess the genetic diversity of lettuce cultivars and the phylogenetic relationships in Lactuca spp. A total of 216 polymorphic bands from seven RAPD primers, four Inter-SSR primers, and five AFLP primer combinations were used to elucidate the genetic similarity among lettuce cultivars. Forty-four lettuce accessions were subdivided into discrete branches according to plant type: crisphead, butterhead, and stem type, with some exceptions. The leafy- and cos-type accessions were intermingled in other groups with no discrete branch indicating that these are more diverse than others. Three accessions, including the Korean cultivar 'Cheongchima', the Korean local landrace 'Jinjam', and the German cultivar 'Lolla Rossa' were classified as the most diverse accessions. Twenty bands were unique in specific cultivars. Among these, three were specific in a plant type; one in Korean leafy type, one in crisphead type, and one in cos type lettuce. In the phylogenetic analysis among Lactuca species, L. saligna, L. serriola, and L. georgica clustered in a sister branch of the L. sativa complex. Two L. virosa accessions show the highest intra-specific relationships. L. perennis outlied from all the other Lactuca species at a genetic similarity of 0.53 and clustered with two Cichorium species, C. intybus and C. endivia, with genetic similarity of 0.67. The phylogenetic tree was supported by data from polymorphism of chloroplast genome which was revealed by PCR-RFLP.

• ALGAE
• /
• v.28 no.4
• /
• pp.307-330
• /
• 2013

The genus Cryptomonas is easily recognized by having two flagella, green brownish color, and a swaying behavior. They have relatively simple morphology, and limited diagnostic characters, which present a major difficulty in differentiating between species of the genus. To understand species delineation and phylogenetic relationships among Cryptomonas species, the nuclear-encoded internal transcribed spacer 2 (ITS2), partial large subunit (LSU) and small subunit ribosomal DNA (rDNA), and chloroplast-encoded psbA and LSU rDNA sequences were determined and used for phylogenetic analyses, using Bayesian and maximum likelihood methods. In addition, nuclear-encoded ITS2 sequences were predicted to secondary structures, and were used to determine nine species and four unidentified species from 47 strains. Sequences of helix I, II, and IIIb in ITS2 secondary structure were very useful for the identification of Cryptomonas species. However, the helix IV was the most variable region across species in alignment. The phylogenetic tree showed that fourteen species were monophyletic. However, some strains of C. obovata had chloroplasts with pyrenoid while others were without pyrenoid, which used as a key character in few species. Therefore, classification systems depending solely on morphological characters are inadequate, and require the use of molecular data.

• The Korean Journal of Mycology
• /
• v.46 no.4
• /
• pp.375-382
• /
• 2018

Members of the genus Mortierella (Mortierellales) are filamentous fungi, which are found on nearly all substrates, but more frequently in soil. Till date, 7 species of Mortierella have been reported in Korea, but being a ubiquitous group with high species diversity in temperate zones, this number is still low. During a survey of fungal biodiversity in Korea, we collected many isolates of Mortierella, and through morphological and molecular phylogenetic analyses, identified them to be 3 previously unrecorded species, namely, M. chienii, M. epicladia, and M. gamsii. A total of 10 Mortierella species in Korea, including the 3 species reported in the present study, are widely distributed in 5 out of 7 phylogenetic groups of this genus. This indicates that the diversity of Mortierella was so far underestimated in Korea. Multi-locus sequence analysis is required to provide a more reliable backbone for some uncertain phylogenetic groupings and to more clearly define a species of Mortierella, which would encourage deeper research in the diversity and ecological roles of Mortierella and allied genera.

• Parasites, Hosts and Diseases
• /
• v.56 no.6
• /
• pp.583-588
• /
• 2018

Although widely studied, the natural diversity of the hard tick is not well known. In this study, we collected 194 sequences from 67 species, covering 7 genera of hard tick. The 5' region of the mitochondrial cytochrome c oxidase subunit 1 region (586 bp) has been used to investigate intra- and inter-species variation and the phylogenetic tree of neighbor joining method has been used for assessment. As a result, by comparing the K2P-distance of intra- and interspecies, 30 samples (15.2%) shown that interspecies distance was larger than the minimum interspecfic distance. From the phylogenetic analysis, 86.8% (49) of the species were identified correctly at the genus level. On deeper analysis on these species suggested the possibility of presence cryptic species. Therefore, further work is required to delineate species boundaries and to develop a more complete understanding of hard tick diversity over larger scale.

• Journal of Veterinary Science
• /
• v.22 no.6
• /
• pp.66.1-66.9
• /
• 2021

Background: Maedi/Visna virus (MVV) is a contagious viral pathogen that causes considerable economic losses to the sheep industry worldwide. Objectives: In China, MVV has been detected in several regions, but its molecular characteristics and genetic variations were not thoroughly investigated. Methods: Therefore, in this study, we conducted next-generation sequencing on an MVV strain obtained from northwest China to reveal its genetic evolution via phylogenetic analysis. Results: A MVV strain obtained from Inner Mongolia (NM) of China was identified. Sequence analysis indicated that its whole-genome length is 9193 bp. Homology comparison of nucleotides between the NM strain and reference strains showed that the sequence homology of gag and env were 77.1%-86.8% and 67.7%-75.5%, respectively. Phylogenetic analysis revealed that the NM strain was closely related to the reference strains isolated from America, which belong to the A2 type. Notably, there were 5 amino acid insertions in variable region 4 and a highly variable motif at the C-terminal of the surface glycoprotein (SU5). Conclusions: The present study is the first to show the whole-genome sequence of an MVV obtained from China. The detailed analyses provide essential information for understanding the genetic characteristics of MVV, and the results enrich the MVV library.

• The Korean Journal of Mycology
• /
• v.52 no.2
• /
• pp.97-108
• /
• 2024

In this study, three fungal isolates belonging to the phylum Ascomycota under classes Leotiomycetes, Eurotiomycetes, and Sordariomycetes were isolated from soil in Korea. These species were designated as KNUF-22-003, KNUF-22-005, and KNUF-20-NI016, respectively, and identified based on their phylogenetic relationships and morphological characteristics. The isolates were confirmed through molecular phylogenetic analyses of their internal transcribed spacer (ITS) region, 28S rDNA large subunit (LSU), and actin (ACT1 ) gene sequences. Cultural and morphological characteristics of strains KNUF-22-003, KNUF-22-005, and KNUF-20-NI016 were matched with Chaetomella oblonga CBS110.78^T, Oidiodendron chlamydosporicum CBS403.69^T, and Sarocladium subulatum CBS217.35^T, respectively. To the best of our knowledge, this is the first report on C. oblonga, O. chlamydosporicum, and S. subulatum in Korea.

• Mycobiology
• /
• v.42 no.1
• /
• pp.12-16
• /
• 2014

We isolated and examined a new Alternaria sp., which causes leaf spots on Peucedanum japonicum in Korea, by using molecular and morphological methods. Phylogenetic analysis based on a combined internal transcribed spacer region analysis and two protein-coding genes (gpd and Alt a1) demonstrated that the causal fungus was most closely related to A. cinerariae and A. sonchi, and relevant to A. brassicae. However, conidial morphology indicated that it is a novel species within the genus Alternaria, and therefore we have assigned the fungus a new name in this study.

• Mycobiology
• /
• v.29 no.2
• /
• pp.73-79
• /
• 2001

The Polyporaceae is a chaotic mass of genera having poroid hymenophores in the Aphyllophorales. To classify the Polyporaceae into more natural groups, phylogenetic analyses were performed using nuclear small subunit ribosomal DNA sequences. Thirty-six species from the families of the Polyporaceae, the Hymenochaetaceae, the Ganodermataceae, the Corticiaceae, the Bondarzewiaceae, the Meruliaceae, the Steccherinaceae and the Lentinaceae were phylogenetically compared. By performing maximum parsimony analysis, seven phylogenetically meaningful groups were identified and discussed. The hyphal system, presence or absence of clamps, and the type of rot were found as important characters in defining the groups. Each group was phylogenetically significant enough to be a core member of each family when the Polyporaceae was split into smaller and more natural families.