The root-lesion nematode Pratylenchus spp. is the most important plantparasitic nematode due to its worldwide distribution, wide host ranges, and migratory endoparasitic characteristics. One population of Pratylenchus collected from the giant pussy willow (Salix chaenomeloides Kimura) in the Andong area as part of a nematode survey in Korea was characterized morphologically and by molecular methods. The analysis of morphological measurements and morphometric characteristics, as well as DNA sequencing of the rRNA large subunit (LSU) D2/D3 expansion segments and the internal transcribed spacer (ITS) gene sequence, confirmed the identity of this population as P. hippeastri. This study is the first report of P. hippeastri associated with Salix chaenomeloides in Korea and worldwide. Further studies on distribution and pathogenicity in different P. hippeastri host crops, such as grapevines, strawberries, and apples, are necessary. The taxonomic keys to 16 Pratylenchus species in Korea are provided.

A survey of plant-parasitic nematodes (PPNs) was carried out in medicinal crop cultivated fields from July to August in 2023. Three-leaf ladybell, Adenophora triphylla var. japonica is a highly valued medicinal plant that is used to treat or prevent bronchitis, cough, cancer, and obesity in Korea. A. triphylla plants with small root-galls were observed in a field of Yeongju Agricultural Technology Center, which were identified as a root-knot nematode. Additional morphological and molecular analyses studies were performed and identified as Meloidogyne hapla, Northern root-knot nematode. Population densities of M. hapla ranged from 20~30 nematodes per 100 cm3 of soil. M. hapla was detected at lower densities in soil compared to other infected host crops, but there are concerns about damage to M. hapla since A. triphylla is cultivated for more than two years once planted. Our results indicate that A. triphylla roots damage by M. hapla were identifed, it is necessary to prepare control methods such as registration of applicable nematicides and crop rotation.

Perilla plant is a special crop that is used as oilseed and food in Korea. Root lesion nematodes have caused great damage to perilla plants, so for effective management of root lesion nematodes, it is necessary to understand their ecology in perilla. In this study, we investigated the effect of temperature in the development of Pratylenchus penetrans (Pp) and Pratylenchus vulnus (Pv) when the nematodes infected the perilla plant. To estimate the effect of temperature, we assessed the reproduction factor (RF); final population/initial population (Pf/Pi) of these two nematode species. We used perilla plants as inoculated hosts and investigated the density of nematodes at 10 weeks after inoculation. As a result, the RF of Pp was highest at 20°C (0.41 (1st test), 2.2 (2nd test)) followed by 25, 30, and 15°C. The RF of Pv was highest at 30°C (9.84 (1st test), 31.39 (2nd test)), followed by 25, 20, and 15°C. Comparing the RF by temperature between Pp and Pv, Pv was higher than Pp at all temperatures used in the test. This study showed the optimal development temperature of Pp was 20-25°C and Pv was 30°C, respectively.

2017년 이후 강원도 고랭지배추는 클로버씨스트선충에 의한 피해를 받아 왔다. 저항성 배추 품종 재배는 씨스트선충 피해를 줄일 수 있는 가장 경제적인 방제 방법이다. 본 연구에서는 클로버씨스트선충 저항성 배추 신품종 육성을 위한 육종 소재 탐색을 위해 배추류 유전자원 총 57 자원을 대상으로 클로버씨스트선충에 대한 저항성 검정을 수행하였다. 배추 (Brassica rapa subsp. pekinensis), 순무 (B. rapa), Brassica sp., 갓 (B. juncea), 겨자류 (B. carinata, B. tournefortii), 경수채 (B. rapa subsp. nipposinica), 다채 (B. rapa subsp. narinosa), 평지 (B. rapa var. perviridis), 루타바가 (B. napus var. napobrassica), 로켓샐러드 (Eruca sativa) 54자원은 뿌리에 클로버씨스트선충 암컷이 300개 이상 증식되어 매우 감수성인 것으로 나타났다. 겨자류 2자원 (B. carinata, B. tournefortii)도 클로버씨스트선충 암컷이 각각 144개, 110 개 증식되어 감수성인 것으로 나타났다. 반면, 겨자류 중 에서 African mustard (B. tournefortii, 씨앗은행 관리번호 IT218058)는 클로버씨스트선충 암컷이 평균 4±1.8로 증 식되어 저항성인 배추류 유전자원인 것으로 나타났다. 본 연구에서 선발된 African mustard (IT218058)는 클로버씨 스트선충 저항성 배추 품종 육성을 위한 육종 소재로 활용 가능할 것으로 판단된다.

국내 들깨 재배지의 식물기생선충 감염현황을 조사하기 위해 2020년 1월 21일부터 10월 27일까지 8개 시군의 노지, 시설 들깨 재배지에서 채취한 토양 시료 51점을 분석하였다. 들깨 재배지에는 뿌리썩이선충류, 나선선충류, 뿌리혹선충, 위축 선충이 감염되어 있었으며, 뿌리썩이선충 (39%)과 나선선충 (55%)이 다른 선충에 비해 높은 감염률을 보였다. 들깨는 연작연수가 증가할수록 뿌리썩이 선충의 발생 빈도는 증가하는 추세를 보였으며, 11년 이상 연작하면 5년 미만일 때보다 발생 빈도가 2배 이상 증가하였다. 잎들깨와 종실용 들깨 재배지에 감염된 선충 종류와 밀도는 차이를 보였다. 들깨 검출 선충 가운데 경제적으로 중요한 뿌리썩이선충의 분자생물학적 종 동정 결과, 2속 3종 (Pratylenchus penetrans, P. vulnus, Pratylenchoides leiocauda)의 뿌리썩이선충이 감염되어 있는 것으로 나타났다. 본 연구 결과에 따라, 들깨 밭의 선충 관리 전략 수립 을 위해서는 뿌리썩이선충이 문제 선충이라는 점이 고려 되어야 할 것이다.

선충포식성 곰팡이는 선충을 포획하기 위하여 다양하고 특수한 기관을 사용한다. 국내 성주지역의 참외 경작지 뿌리 주변의 토양에서 3차원 접착 고리를 형성하여 선충을 포획하는 곰팡이를 분리하였다. 곰팡이의 미세형태 구조를 관찰한 결과 분생포자병은 직립형으로 길이는 290~528 (342.8) μm으로 길었으며, 계란형의 30.5 × 20.3 μm 크기를 가진 1~3개의 분생포자를 형성하였다. 균주의 rDNA의 5.8 S 영역의 염기서열을 분석한 결과, Arthrobotrys속의 계통군에 속하였으며, 특히 Arthrobotrys sinensis와 99%의 유사성을 보였다. 형태적 특징과 분자생물학적 계통 분석을 바탕으로 본 균주는 A. sinensis로 확인되었으며, 이는 국내 미기록종으로 식물기생성선충의 생물학적 조절을 위한 하나의 자원이 될 수 있다.

We reported a new white soybean cyst nematode, Heterodera sojae in 2016. This species is closely related to H. glycineswhich has the same host plant. Morphological observations of the cyst, female, male and second-stage juveniles indicatedthat this species is differed from those of H. glycines. Cysts of H. sojae appeared more round, shining and darker thanthat of H. glycines. The distribution of this new cyst nematode in soybean field in Korea is unknown yet. In 2016, 270soil samples were collected from soybean fields and examined the existence of H. glycines and H. sojae. Total of 111samples (41.1%) contained cysts. Among them 77% were H. glycines and 23% were H. sojae. Our results suggest thatextensive researches are required for white soybean cyst nematode.

This study is the identification of root-knot nematode (RKN), Meloidogyne hapla, from strawberry in Korea using molecular analyses. Strawberry plants showed localized stunting and galled roots. Molecular analyses of COⅡ/lrRNA, 28S rDNA D2-D3 segment and internal transcribed spacer (ITS) region were employed for the identification of Meloidogyne spp. Polymerase Chain Reaction (PCR) amplification of COⅡ/lrRNA region produced a single fragment ca 528bp. Restriction digestion of the amplified PCR products with Dra1 enzyme produced two fragments at 200 and 250bp indication M. hapla. 28S rDNA D2-D3 segment and ITS were cloned and sequenced. 28S rDNA D2-D3 segment and ITS region produced a single fragment of 1004bp and 560bp, respectively. In BLAST search in Genbank, all sequences accord with other known M. hapla. As a result, all of the RKN samples were M. hapla. This study suggests that the dominant species of RKN on strawberry is M. hapla in Korea.

The Baermann funnel method requires three to four Kimwipes tissues for clean nematode extraction. To find more efficient and economical nematode extraction paper, 14 different kinds of tissue papers were tested and compared with Kimwipes tissues. Nematode species used in the extraction efficiency test were juvenile (J2) of Heterodera spp., J2 of Meloidogyne spp., Pratylenchus spp., Rhabditis spp., Acrobeloides spp., Panagrolaimus spp., Poikilolaimus spp. and Diplogasterida. Extraction efficiency varied between 42.0 to 88.8%. Considering costs, extraction efficacy, and cleanness, one sheet of Pulling Kitchen Towel (MONALISA Co., Korea) is selected.

For management of soybean parasitic cyst nematodes, this study was conducted to investigate the resistance of the Korean soybean cultivars to HG type 2.5.7 of Heterodera sojae. Among the 44 Korean soybean cultivars, there was only one resistant cultivar ‘Namcheon’. ‘Sobaeknamul’, ‘Socheng No. 2’, ‘Pungsannamul’, ‘Cheongja’, ‘Miryang’ and ‘Daewon’ were moderately resistant to HG 2.5.7 of H. sojae populations. Eleven cultivars including ‘Paldal’ were moderately susceptible and the other cultivars were susceptible. Therefore, soybean cultivar ‘Namcheon’ should be cultivated in H. sojae infested fields, until varieties resistant against Heterodera species are more developed or identified. Moreover, ‘Namcheon’ is not recommended for cultivation because very weak to soybean mosaic virus, and it will be a candidate with resistant cultivar breeding resource.

This study was conducted to evaluate resistance of 10 different cowpea cultivars which were introduced from the United States against two major root-knot nematodes, Meloidogyne arenaria and M. incognita, that affect greenhouse crop cultivation in Korea. The results showed that the resistance of the tested cultivars to the root-knot nematodes varied with the cultivar. Texas Cream 40 showed moderate resistance to M. arenaria whereas the other cultivars were susceptible. Purple Hull Pinkeye and Texas Pinkeye Purple Hull were found to be resistant to M. incognita, whereas Mississippi Silver showed moderate resistance and the other cultivars were susceptible. As the cultivars exhibit resistance to M. arenaria and M. incognita, such cultivars resistant to root-knot nematodes should be considered during the cultivation of cowpea as a green manure crop.