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.

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.

Plant-parasitic nematodes causes yield losses of more than $100 million per year in the world. Among them, soybeancyst nematode (Heterodera glycines Ichinohe) causes the greatest yield loss to soybean compared to any other pest worldwide.SCN causes yield reductions by feeding on plant nutrients, retarding root growth and inhibiting Bradyrhizobium japonicum(Kirchner) Buchanan nodulation. The primary methods for controlling SCN include planting resistant cultivars and rotationwith nonhost crop. In order to control SCN, we should be breeding resistant soybean cultivars which has resistant genefor this pest. The research that can minimize the damage of the soybean yield is still insufficient, comprehensive andsystematic research is urgently required. Current researches in our lab are discussed.

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.

To select resistant oil seed crops against two species of root-knot nematodes, M. incognita and M. arenaria, 10 cultivars of sesame (Sesamum indicum) and 10 cultivars of perilla (Perilla frutescens var. japonica) were screened in greenhouse pot test. All sesame cultivars tested were resistant to M. incognita but susceptible to M. arenaria. While, perilla was resistant to both Meloidogyne species. Therefore, perilla cultivars could be used as rotation crops in greenhouses infested with both M. incognita and M. arenaria. But, sesame cultivars only can be used as a rotation crops in greenhouses infested with M. incognita but not for M. arenaria.

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.