• Journal of agriculture & life science
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• v.46 no.4
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• pp.101-111
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• 2012

Soybean cyst nematode(SCN) (Heterodera glycines Ichinohe) causes the greatest yield loss to soybean compared to any other pest worldwide. Yield loss due to SCN is estimated 7.6 million megagrams in the USA and nearly 9 million worldwide. SCN causes yield reductions by feeding on plant nutrients, retarding root growth, and inhibiting Bradyrhizpbium japonicum(Kirchner) Buchanan nodulation. The primary methods for controlling SCN include planting resistant cultivars and rotation with nonhost crops. Genetically diverse field populations of SCN combined with the limited germplasm base of commercial soybean for resistance could potentially leads to population shifts over time, and this makes controlling H. glycines more difficult. This paper reviewed the importance of soybean, soybean cyst nematode, researches on resistance to SCN, and prospects. Tremendous effort must still be endeavored for elucidating resistance mechanisms and managing H. glycines in the soybean field.

• Korean journal of applied entomology
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• v.58 no.1
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• pp.49-54
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• 2019

Clover cyst nematode, Heterodera trifolii are one of the major pests that damage Chinese cabbage in high land cultivation area and have recently been distributed in Korea. This study was conducted to investigate the effect of temperature and inoculation density on the proliferation of clover cyst nematode. The clover cyst nematode was proliferated at $15-30^{\circ}C$ and the egg, female adult and cyst number was the highest at $20^{\circ}C$. As the inoculation density increased, the number of female cyst nematodes increased with the inoculation density and when 16 eggs were inoculated per gram of soil, the amount of growth, number of egg and cyst was the highest. Number of females and eggs were formed more in cabbage than in kale regardless of inoculation density. Chinese cabbage was a favorable host for clover cyst nematode growth than kale.

• Research in Plant Disease
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• v.26 no.2
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• pp.72-78
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• 2020

Clover cyst nematode, Heterodera trifolii, is one of the most important plant-parasitic nematode on Kimchi-cabbage in highland in Korea. Recently, a demand of soil disinfection machine for fumigants is increasing. This study was conducted to assess the control effects of a newly developed prototype soil disinfection machine to the cyst nematode. Two fumigants, dimethyl disulfide (DMDS) and metam sodium (MNa), were treated using the machine in a field, which was infected with the cyst nematode. After 4 weeks, control effects of fumigants were assessed as eggs hatching rates inside of cysts extracted from the soil, and as a number of females reproduced in roots of Kimchi-cabbage. DMDS (39 l/10 a) suppressed over 99.0% of the eggs hatching rate and the number of females reproduced. On the other hand, MNa (29 l/10 a) controlled the egg hatching rates from minimum 78.3% to maximum 99.4%, and the number of females from 34.7% to 49.3%. The control effects of two fumigants to clover cyst nematode by treated depth were no significant differences statistically. These results showed that DMDS treatment using the soil disinfection machine was expected to have the control effects for the clover cyst nematode.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.339-345
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• 2018

The sugar beet cyst nematode (SBCN), Heterodera schachtii first detected in Taebaek, Gangwon-do in 2011, is one of the major plant parasitic nematodes that cause economic damage to the Chinese cabbage in highland regions. In addition, the distribution of clover cyst nematode (CCN), H. trifolii was confirmed in the highland Chinese cabbage cultivated regions in 2017. In order to investigate the spread of cyst nematodes, this study has been conducted since 2013 in the highland Chinese cabbage cultivation area. In addition, in 2017, the Real-Time PCR technique with the species-specific primer was used to investigate those two cyst nematodes and the soybean cyst nematode (SCN), H. glycines which is known for its distribution in Korea, focusing on the main production regions of highland Chinese cabbage cultivation. The number of infected fields in the Chinese cabbage plantation in highland increased every year to confirm distribution in Taebaek, Samcheok, Jeongseon and Gangneung in 2017, and the cumulative number of infection fields reached 245 by 2017. Of the 41 possible cyst nematode samples for PCR analysis, 61% were CCN, only 9.8% of the SBCN and 29.3% of the SCN were identified. Therefore, some of the previously known SBCN or CCN discoveries are likely to have been infected with SCN. It is believed that the CCN needs to be controlled in the future as CCN have been found to be dominant species in the highland Chinese cabbage plantation regions.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.329-335
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• 2021

Chinese cabbage fields have been damaged by cyst nematodes in highland of Gangwon province in Korea since the year 2011, and clover cyst nematode (CCN) is one of the most problematic cyst nematodes in the crop. To investigate the plant resources for breeding new Chinese cabbage cultivar, which is resistant to CCN, screening for resistance of fifty-seven Brassicaceae plant resources to CCN was conducted. Among the plant resources, fifty-four plant resources (Brassica rapa subsp. pekinensis, B. rapa, Brassica sp., B. juncea, B. carinata, B. rapa subsp. nipposinica, B. rapa subsp. narinosa, B. rapa var. perviridis, B. rapa var. perviridis, B. napus var. napobrassica, and Eruca sativa) were very susceptible to CCN and the number of females on roots was more than 300. Two plant resources (B. carinata and B. tournefortii) with more than 100 females on roots were susceptible to CCN. However, African mustard (B. tournefortii, Korean Genebank accession no. IT218058) was resistant to CCN because of the small number of females (4±1.8) on roots. This study showed that African mustard (IT218058) was valuable as a breeding material for Chinese cabbage, which is resistant to CCN.

• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.1-5
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• 2021

Radish is one of the major vegetable crops and has been damaged economically by the causal agent of Fusarium wilt disease, Fusarium oxysporum f. sp. raphani (FO) in the highlands of Gangwon province, Korea. Recently, clover cyst nematode, Heterodera trifolii(HT), occurred in highland of Jeongseon area and poses a threat to radish plants. The nematodes, besides causing direct damage to radish plants, possess the capability to synergize with other plant pathogens, leading to the development of a disease complex. The aim of this study was to investigate the interaction between FO and HT in radish plants. The length of plants co-infected with both FO and HT was shorter than that of plants infected with FO alone, but there was no statistically significant difference. However, the disease severity was much higher in the plants co-infected with both FO and HT(1.60±0.97) compared to FO alone(0.20±0.42)(df=3, F=10.17, p<0.001). Disease incidence was also about two-fold higher in plants co-infected with both FO and HT (80%) compared to FO alone (44%). These results suggested that the clover cyst nematode should be considered in the management of Fusarium wilt disease in the highlands of Gangwon province.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.389-403
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• 2016

Sugar beet nematode (Heterodera schachtii Schmidt) was first detected in 2011, in Chinese cabbage grown in the highland areas of Korea. Chemical control of the nematode by nematicides is not feasible due to its cyst-forming characteristics; therefore, the cultivation of non-host crops is a preferable alternative to utilize nematode-infected fields. In this study, a total of 276 plant cultivars belonging to 18 different families were screened to evaluate their resistance to the nematode. Based on the number of cysts formed following nematode inoculation, the tested crops were classified into 3 levels: susceptible, moderately susceptible, and resistant/immune. Among the 276 cultivars tested, 106 cultivars were susceptible, 40 cultivars were moderately susceptible, and 130 cultivars were resistant/immune. Among the resistant/immune cultivars, cyst formation was not observed on eggplant, tomato, lettuce, perilla, carrot, celery, watermelon, oriental melon, cucumber, pumpkin, chives, onion, welsh onion, balloon flower roots, deodeok (Codonopsis lanceolata), Jandae (Adenophora triphylla), and bean. Therefore, these plants are regarded as immune to the cyst nematode. However, many crops belonging to Solanaceae, Asteraceae, Chenopodiaceae, and Poaceae families showed moderate susceptibility or immunity, depending on the crop or cultivar. This study provides a basis for alternative crop recommendations for sugar beet nematode cyst-infected farms in Chinese cabbage production areas.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.5-13
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• 2001

Two unrecorded species of Heteroderinae, Clobodera hypolysi Ogawa, Ohshima and Ichinohe, 1983 and Sarisodera hydrophila Wouts and Sher, 1971 from Korea were firstly reported. The Korean specimens well correspond with the original description of Globodera hypolysi except stylet length of the juveniles, slightly shorter (21~24 vs. 24~25 $\mu$m) and shorter distance from the anus to the fenestra in cyst (22~50 vs. 25~80$\mu$m). The measurements of Korean specimen of Sarisodera hydrophila are slightly short compared with the type species; Female body length 367.2~597.6$\mu$m vs 359~688$\mu$m; Stylet length 37~44$\mu$m vs 38~46$\mu$m; Male body length 662~11987m vs 579~1405$\mu$m; stylet length 37~43.8$\mu$m vs 38~46$\mu$m. Juvnile body length 460~536$\mu$m vs 466~5587m. stylet length 32~387m vs 39~43$\mu$m.

• Korean journal of applied entomology
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• v.19 no.1 s.42
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• pp.31-34
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• 1980

In pot experiment, relations between soybean cyst nematode, Heterodera glycines, and growth and yield of soybean were followed. Soybean growth and nodule development in plots which inoculated more than 16 cysts were reduced greatly from two month after inoculation. Tolerance limit was about 20 cysts per 500g of soil at seeding period. There was $60\%$ loss of grain yield 낀hen nematode population was 1 cyst/g of soil at seeding period. Reproduction of soybean cyst :nematode was good when initial population had been low. So, the final population was no difference depend on inoculation density.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.413-420
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• 2017

Sugarbeet cyst nematode (Heterodera schachtii) has recently been detected as a severe pest of Chinese cabbage fields in Korea. Two studies were performed to evaluate the effect of inoculation density of H. schachtii and plant age of Chinese cabbage on the final population of the nematodes. Chinese cabbage inoculated with high inoculation density (4 juveniles or eggs/g soil) showed significant differences in the number of cysts, females and eggs. The 40 day- old plants inoculated with high nematode densities yielded the highest nematode populations after 30 and 60 days of inoculation, compared with other plant age groups (0, 20, 30 day-old)used in the experiment. We, thus, summarize that, maximum nematode multiplication rates are made on comparatively older plants at the high nematode densities. Therefore, taking plant age into consideration at the transplanting of Chinese cabbage was recommended for the management of H. schachtii.