• Korean journal of applied entomology
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• v.53 no.4
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• pp.465-472
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• 2014

The tobacco whitefly, Bemisia tabaci, infest the Oriental melon and give significant economic damage along with its virus-vectoring activity. Various biotypes of B. tabaci have been well known and are classified depending on the severity of crop damage and insecticide susceptibility. In this study, B. tabaci adults were collected in the melon fields located in Poongchun-myeon, Andong, Korea and diagnosed on their biotypes using PCR molecular markers. From the all the 11 greenhouses, B. tabaci biotype Q was identified. In addition, biotype B adults were also found from the 4 greenhouses. These results report the first occurrence of B. tabaci at the Oriental melon farms in Gyeongbuk province with mixed infection by the two biotypes in the area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.199-213
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• 2020

Grain size and shape are the two important components contributing to rice yield and quality. To analyze traits related to grain-shape, a total of 272 varieties derived from japonica, japonica black and Tongil-type rice accession in Korea were evaluated in this study. The traits, grain length (GL), grain width (GW), grain thickness (GT), length to width ratio (RLW), and 1000-grain weight (TGW) were measured and replicated 10 times. Genes (GW2, GS3, qGL3, qSW5, GS5, TGW6, GW7, and GW8) related to grain-shape were validated in the accessions using specific DNA marker sets. K-mean clustering of the accession based on phenotypic data revealed three groups: group 1 was classified by GW and GT and included most of japonica type, group 2 was classified by RLW and GL reached a medium size and possessed a half spindle-shaped type, and group 3 was classified by TGW, reached a long size and possessed a semi-round shape. In validation tests using the marker sets, both gw2 and tgw6 were validated in less than 1% of the tested accessions and two allelic types, qgl3 and gw8, were only verified in Tongil-type accessions. For GW8 and GW2, any different amplicons were not amplified in any japonica or Tongil-type accessions, respectively. In order to suggest the representative grain-shape gene combinations for each ecotype, the allelic combinations were evaluated by PCR analysis. Cj1 and 2 in japonica (Cj1-7), Cj_b1 and 2 in japonica-black (Cj_b1-3), and CT3 in Tongil-type (CT1-13) turned out to be the dominant combination in each ecotype, respectively. In addition, the results revealed that introgression of four genes (gw2, gs3, qSW5, and GS5) would expand the diversity of grain shape in Korean japonica varieties. The gene combinations information could be utilized practically to understand or enhance grain shape in japonica rice breeding program.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.320-330
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• 2007

Mitochondrial 16S DNA sequences of Bemisia tabaci which were collected on rose greenhouse of Iwol and Jinchen in Chungbuk and red pepper field of Miryang, Gyeongnam, were analyzed. The mtCOI PCR product of B. tabaci collected on red pepper field of Miryang were digested with EcoT14I (Sty I) into two fragments 555bp and 311bp, while the PCR product of B. tabaci collected on rose greenhouse of Iwol were digested with Sty I into two fragments of 560bp and 306bp. As a result, B. tabaci collected on red pepper reveal biotype Q and those on rose greenhouse was biotype B. These was difference between two biotypes in insecticide susceptibility, and the biotype B was more susceptible than biotype Q. As a result of foliar systemic test, root-uptake systemic test and residual effect, the biotype B was more susceptible. In case of inhibition effect on enzyme activities of fenitrothion (organophosphorous) and fenothiocarb (carbamate), those of biotype Q was higher than those of biotype B. These results indicate that biotype Q was more resistant than biotype B against 12 insecticides.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.179-188
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• 2009

Nymphal development of the B and Q biotypes of Bemisia tabaci was normal on all seven tomato varieties tested. However, their nymphal development was different on red pepper varieties. B biotype was not normally developed on nine red pepper varieties tested. On the contrary, Q biotype was normally developed, but its adult emergence rate was very low in Nokkwang variety than in other eight varieties. The EPG analysis of the feeding behavior of Bemisia tabaci showed that B and Q biotypes had different duration of phloem phases on red pepper. Q biotype showed longer phloem phases than B biotype. On Nokkwang variety, Q biotype had short phloem phases and did not prefer to feed on Nokkwang variety. Interestingly, Q biotype was found to have long duration of phloem phases on eight red pepper varieties, but B biotype did not prefer to feed on red pepper varieties. However, both biotypes did not show any difference in feeding time on tomato varieties.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.401-408
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• 2007

The feeding behaviors of 2 biotypes (type B and Q) of tobacco whitefly, Bemisia tobaci, were monitored using EPG technique on tomato and pepper plants treated 3 insecticides for controlling whiteflies, for examples, acetamiprid, spinosad and thiamethoxam. After treatment of three insecticides with recommended concentrations to tomato and pepper plants, EPG waveforms were recorded during 6 hours. The characteristic patterns of feeding behaviors investigated were as follows; time consumed by withdrawal of proboscis, total non-penetration time, total stylet pathway pattern time and total phloem feeding time. There was somewhat difference among 3 insecticides tested. As a result of investigation of total duration showed the stylet pathway activity due to the reaction against all tested insecticides, the Q biotype showed fewer time than those from the B biotype. The B biotype showed more frequent stylet pathway activity patterns during whole recording time and a shorter phloem ingestion time than those from the Q biotype. In result of prior up (non-penetration) time representing the reaction against the insecticide treated, the time of B biotype was more faster than that of the Q biotype, so it was considered that the B biotype was more sensitive to the tested insecticides. Therefore, our results revealed a clear difference in feeding behaviour between the B and Q biotypes of B. tabaci. Also, it was investigated that B biotype was susceptible to the 3 insecticides.

• Korean Journal of Environment and Ecology
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• v.12 no.2
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• pp.119-130
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• 1998

The purposes of this study were to investigate vegetation structure and to present management plan of mountain type green space in Kangwhado, Inchon. The actual vegetation in survey sites(11,331ha) was divided into 19 community types. It was consisted of secondary forest(92.32%) which was Quercus acutissima, Pinus densiflora-Q. acutissima, and Q. mongolica community so on. Artificial planting forest area, such as Robinia pseudoacacia and Pinus rigida forest and others, was 5.40%(612ha) and it was less than cases in other cities in the Metropolitan area. According to the classification by TWINSPAN, 57 survey plots were divided into seven community types; P rigida(community A), Q. acutissima(community B) P. densiflora-Q. acutissima(community C), Q. acutissima-P. densiflora (community D), P. densiflora-Carpinus laxiflora-Q. serrata-Q. acutissima(community E), Q. serrata-Q. mongolica(community F), and Zelkova serrata-Acer mono(community G). From this result, ecological succession trend of vegetation in this area seems to be change from P. densiflora forest through Q. acutissima forest to Q. mongolica, Q. serrata, and C. laxiflora forest. It was similar to the ordinary successional trend of temperate deciduous forest in middle area, Korea. In addition, this study area was showed acid soil(pH 4.17). Therefore, there is a need for managing the soil environment for effective vegetation management.

• Korean Journal of Environment and Ecology
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• v.25 no.1
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• pp.37-46
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• 2011

This study was written about the actual vegetation map by researchig current vegetation and on-site vegetation in the Deogyusan National Park. Current vegetation patterns were classified into 42 types according to correlation. And Quercus mongolica forest was 39.08% out of the total forest vegetation, and was dispersed the most widely. Next were Q. variabilis, Pinus densiflora, and Fraxinus mandshurica forests in order, so that the forests of Deogyusan are different from those of another national parks in that F. mandshurica forest is more widely dispersed. Forest vegetation of Deogyusan national park is broadly classified into three types: deciduous broad-leaved forest (Quercus forest and valley forest), coniferous forest(P. densiflora forest), and sub-alpine forest(Taxus cuspidata forest, Abies koreana, Rhododendron schlippenbachii shrub-forest, and prairie). Distribution of DBH of Q. mongolica and Q. variabillis had a higher frequency of young individuals and middle individuals, Q. serrata and Carpinus laxiflora had a higher frequency of young individuals, suggesting a continuous domination of these species over the other species for the time being. In contrast, F. mandshurica appeared limited to the valley of the sheet and a higher frequency of young individuals, suggesting a continuous domination of these species the development of a climax forest terrain. P. densiflora, Betula davurica, Cornus controversa, B. costata, A. koreana and T. cuspidata had a formality distribution, suggesting a continuous domination of these species over the other species for the time being.

• Korean Journal of Environment and Ecology
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• v.37 no.5
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• pp.347-366
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• 2023

In the present study, the vegetation was classified using the phytosociological method and canonical-correlation analysis (CCA) was implemented to analyze correlation between community structure and environmental factors in the natural habitats of forest byproducts, especially medicinal plants, such as Cudrania tricuspidata, Sorbus commixta, and Hovenia dulcis, in 2021-2022 to provide primary ecological data to establish environmental conditions for wild vegetable cultivation. A total of 11 plots in five regions, 8 plots in three regions, and 17 plots in 5 regions were selected for the natural habitats of C. tricuspidata in southern Korea, S. commixta in high mountains, and H. dulcis in valleys of central Korea, respectively. The importance value in each community was respectively analyzed as follows, in C. tricuspidata community, the importance value of C. tricuspidata (61.10) was the highest, followed by Celtis sinensis, Pinus thunbergii, Neolitsea aciculata, Styrax japonica, Carpinus coreana, Quercus serrata, and Q. acutissima. In Sorbus commixta community, Q. mongolica (57.21) was the highest, followed by, S. commixta (42.58), Betula ermani, Tilia amurensis, A. pseudosieboldianum, A. tschonoskii var. rubripes, Cornus controversa, Magnolia sieboldii, and Taxus cuspidata. In H. dulcis community, H. dulcis (64.58) was the highest, followed by Zelkova serrata, Cornus controversa, A. mono, Q. serrata, C. cordata, and Juglans mandshurica. As the result of the analysis on DBH of the major species having the high importance value, in C. tricuspidata community, C. tricuspidata, C. sinensis, Neolitsea aciculata, and C. coreana show the density of normal distribution, so the dominant status of these species is likely to continue. In S. commixta community, S. commixta show the density of reverse J-shaped curve, so the dominant status of these species is likely to be stable, and Q. mongolica, B. ermani and T. amurensis, show the density of normal distribution, so the dominant status of these species is likely to continue. In H. dulcis community, C. cordata, and J. mandshurica show the density of reverse J-shaped curve, so the dominant status of these species is likely to be stable, and H. dulcis, Z. serrata, C. controversa and A. mono had a formality distribution, suggesting a continuous domination of these species over the other species for the time being. The results of CCA ordination analysis using 11 environmental factors and 30 communities of three taxa classified by TWINSPAN analysis revealed that the altitude showed the strongest correlation with the vegetation. C. tricuspidata community was distributed on the moderate and gentle northeastern slope at low altitude with the highest pH, C.E.C, Ca²⁺, and Mg² and various P₂O₅, whereas S. commixta community was distributed on the steep slope at high altitude with the highest O.M and T-N and lower P₂O₅, Ca²⁺, Mg²⁺, C.E.C and pH, which is the opposite tendency of the environment of C. tricuspidata community. H. dulcis community was distributed on the gentle northern slope at lower altitude with an average pH, O.M, T-N, Ca²⁺, Mg²⁺, and C.E.C, except higher P₂O₅.