• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.177-180
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• 2008

Worldwide, cyst nematode(Heterodera glycines Ichinohe) is the most destructive pathogen of cultivated soybean. In the USA, current annual yield losses are estimated to be nearly a billion dollars. Crop losses are primarily reduced by the use of resistant cultivars. Nematode populations are variable and have adapted to reproduce on resistant cultivars over time because resistance primarily traces to two soybean accessions. It is important to use diverse resistance sources to develop new nematode resistant cultivars. Soybean PI 494182 is a recent introduction from Japan and found to be resistant to multiple nematode populations. It is yellow seeded and maturity group 0. We have determined inheritance of resistance in PI 494182 using $F_{2:3}$ families derived from cross PI 494182 X cv. Skylla. Skylla is a susceptible parent. Three nematode populations, races 1, 3, and 5, corresponding to HG types 2.5.7, 0, and 2.5.7 were used to bioassay 162 $F_{2:3}$ families in greenhouse experiments. Based on Chi-square tests, a two-gene model is proposed for resistance to race 1 and a three-gene model is proposed for conditioning resistance to both races 3 and 5. Correlation coefficient analysis indicated that some genes conditioning resistance to races 1, 3, and 5 are shared or closely linked with each other. These results will be useful to soybean breeders for developing soybean cultivars for broad resistance to nematodes.

• Korean journal of applied entomology
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• v.34 no.2
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• pp.83-88
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• 1995

Soybean has been cultivated in China for 5,000 years. The soybean cyst neamtode (SCN), Heterodra glycines, was recongnized in Northeastern China in 1899. Currently, it is known to occur in 12 provinces. The biology of SCN was investigated in several provinces. Six races of SCN were identified (race 1, 2, 3, 4, 5 and 7). About f10,000 soybean germplasm lines were evaluated for their resistance to race 1, 3, 4 and 5 of SCN. At least two black-seeded cultivars are resistant to all four races. Several tolerant soybean cultivars with yellow seed coat were released and are in production. Additional resistant cultivars are being developed. Nematicides were not applied in production Potential biocontrol agents and related aspects are being investigated.

• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.251-261
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• 1983

Survey on soybean parasitic nematodes has been undertaken in order to get an ideas about the distribution of nemic fauna. Total 71 soil samples were collected from soybean fields in Gyeongbug and Chungbug provinces. Eighteen species belonging to fourteen different genera were found associated with soybean, Glycine max. The results were as follows: Aphelenchus avenae, Circonemoides informis, Ditylenchus dipsaci, Helicotylenchus pseudorobustus, Heterodera glycines, Hirschmanniella imamuri, Meloidogyne hapla, Meloidogyne incognita, Paratylenchus pandus, Pratylenchus thornei, Pratylenchus vulnus, Psilenchus hilarulus, Rotylenchus sp. Tylenchorhynchus clay toni, Tylenchorhynchus dubius, Tylenchorhynchus nudus, Tylenchus sp. Xiphinema americanum were found in soybean fields. In frequency of occurring nematodes by localities, soybean cyst nematode was higher in Chungbug by $70\%$, while $50\%$ in Gyeongbug. But rook-knot nematode was higher in Gyeongbug by $54.1\%$, while $19.1\%$ in Chungbug. In density of nematode, Heterodera was the most dominant as 200.4 populations per 100ml soil, Meloidogyne as 107.1 populations, Rotylenchus, Xiphinema, Aphelenchus in decreasing order. In survey of loss, density of soybean cyst nematode in heavily infested fields was 155 cysts per 100ml soil while 35 cysts in slightly infested fields. Seventy percent of soybean yields was decreased when comparing with average 64.2kg/10a in heavily infested fields and average 209.5kg/10a in slightly infested. Correlation coefficients among number of soybean cyst and yields, pod weight, number of pod was negative as r- 0.57, 0.47, 0.38 over all localities.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.133-136
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• 1975

Influence of susceptible and resistant soybean varieties to the development of the soybean cyst nematode(Heterodera glycines) was examined. It does not seem likly that there are any differences between varieties in attracting the Second Stage larvae of the nematode. In susceptible varieties, there were large populations and three generations during a ten·week examination period, while the resistant varieties maintained very low populations and had only two generations.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.710-713
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• 1998

Spatial distribution in soil and seasonal population changes of Pasteuria nishizawae first found in Korea from soybean cyst nematode were studied. P. nishizawae infested in 61% of areas in a soybean field; in an average, about 0.3% of 46 cysts and 17.6% of 9 juveniles per 100 g soil were infested with the bacterium. The highest percentages of spore-attached nematodes were found in July (75%) and between soil depth of 11~20 cm. The number of spores per juvenile was positively correlated with the percentage of juveniles with spores (r=0.4203; P＜0.0133), but negatively correlated with the number of juveniles in soil (r=-0.3499; P＜0.042). P. nishizawae completed its life cycle in cyst and produced 1.7$\times$105 spores per cyst.

• Korean journal of applied entomology
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• v.26 no.4 s.73
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• pp.203-207
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• 1987

Studies were conducted to investigate the race distribution of soybean cyst nematode (Heterodera glycines Ichinohe) in Korea. The results are abstracted as follows. The soybean cyst nematode populations collected from Kangwon Province were identified as races 1 and 3; the nematode populations collected from Kyunggi Province were identified as race 3, 5 and c and those collected from Chungnam Province were identified as races 1 and 5. From the total 21 populations 11 populations or 52.4% of the total were race 1; 6 populations or 28.6% of the total were race 5; 3 populations or 14.3% of the total were race 3 and one population or 4.8% of the total were race c. Soybean cyst nematode populations from the same district, at least from the same 'myeon' district were identified as same race. Of these 4, race 3 has not been recorded in Korea yet.

• Korean journal of applied entomology
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• v.27 no.1
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• pp.35-40
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• 1988

The control efficiency of the nematicides, aldicarb and carbofuran, in the population dynamics of the soybean cyst nematode(Heterodera glycines)was evaluated. Nematode viability, penetration and reproduction were examined in greenhouse experiments. Nematode viability(movement) was greatly reduced by aldicard, but mot by carbofuran. Penetration was inhibited by both chemicals. Percentages of Pentration relative to the untreated check 3 days after treatment were 0.4% and 1.7% for aldicarb and carbofuran, respectively. Systemic effect ot the nematicides were observed with both nematicides but effect was greater with aldicarb than with carbofuran. The total effect of the nematicides, applied ay the time of planting soybean in infested soil, appeared to be less than the sum of the contact and systemic effects on the initial population dynamics of H. glycines.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.654-661
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• 2019

The soybean cyst nematode, Heterodera glycines, is a major plant-parasitic nematode that has caused important economic losses to Korea's soybean production. Four species of cyst nematodes, H. schachtii, H. glycines, H. trifolii, and H. sojae, all belong to schachtii group are coexist in field soil in Korea. The rapid identification of the nematode is crucial for preventing crop damage and in decision making for controlling this nematode. This study aimed to develop a species-specific primer set for quantitative PCR (qPCR) assay of H. glycines. The specific primer set (HGF1 and HGR1) for H. glycines was designed based on the cytochrome c oxidase subunit I (COI) sequence of mitochondrial DNA. After optimization, it is possible to identify the H. glycines using a qPCR assay with DNA extracted from a single cyst and single second-stage juvenile (J2). The specificity was confirmed by the absence of SYBR fluorescent signals of three other Heterodera species. A serial dilution of DNA extracted from a single cyst was obtained for the sensitivity test. The result showed that the standard curve of the test had a highly significant linearity between DNA concentration and Ct value (R² = 0.996, slope = -3.49) and that the detection limit concentration of DNA of the primer set was 10 pg of DNA per reaction. Our findings suggested that H. glycines could be distinguished from H. sojae and other Heterodera species when a qPCR assay is used with a specific primer set.

• The Plant Pathology Journal
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• v.38 no.4
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• pp.366-371
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• 2022

The white soybean cyst nematode Heterodera sojae, isolated from the roots of soybean in Korea, is widespread in most provinces of the country and has the potential to be as harmful to soybean as H. glycines. Determining the virulence phenotypes of H. sojae is essential to devising management strategies that use resistant cultivars. Consequently, virulence phenotypes of 15 H. sojae populations from Korea were determined on seven soybean lines and one susceptible check variety. Two different HS types were found to be present in Korea; the more common HS type 2.5.7, comprising 73.3% of the H. sojae populations and the less common HS type 0, constituting only 26.7% of the tested populations. Considering the high frequency of H. sojae adaptation to soybean indicator lines, the PI 88788 group may not be a possible source of resistance while PI 548402, PI 90763, PI 437654, and PI 89772 can be used as resistance sources for soybean breeding programs aimed at developing H. sojae-resistant soybean cultivars in Korea.

• Korean journal of applied entomology
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• v.58 no.1
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• pp.37-47
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• 2019

A survey on the geographical distribution of two soybean cyst nematodes, Heterodera glycines and Heterodera sojae, was conducted in soybean cultivation areas in the Gangwon-do and Chungcheongbuk-do provinces. In 67 fields of 10 counties or cities in Gangwon-do province, H. glycines was detected in 13 fields, H. sojae was detected in five fields, and both species were found in two fields. In 84 fields of nine counties or cities in Chungcheongbuk-do province, H. glycines was detected in 27 fields, H. sojae was detected in four fields, and both species were found in five fields. The diversity and dominance of the plant parasitic nematodes in the Gangwon and Chungbuk provinces were not significantly different among the soybean cultivars. The diversity and dominance index of the plant parasitic nematodes according to the presence or absence of soybean cyst nematodes did not show any significant difference between the soybean cultivation areas of both provinces. The relationship between the soybean cyst nematodes and soil chemical properties showed a low coefficient of determination, and the density of soybean cyst nematodes tended to increase as the pH and available phosphate content in soil samples increased. The soil texture of cyst nematode-detected fields was mostly sandy soils, which amounted to about 60% of the total. As the clay and silt content increased, the density of soybean cyst nematodes tended to decrease, and as the sand content increased, the density of cyst nematodes tended to increase.