Donggeun Kim

Resistance of Commercial Tomato Cultivars to Meloidogyne arenaria and M. incognita

Root-knot nematodes (Meloidogyne spp.) are among the main pathogens of greenhouse crops worldwide. Plant resistance is currently the method of choice for controlling these pests. To select resistant tomato against two common species of root-knot nematodes, M. incognita and M. arenaria, 36 commercial tomato (Lycopersicon esculentum Mill.) cultivars were screened. Seventeen tomato cultivars were resistant to both root-knot nematodes: six in cherry tomato, `Tenten`, `Cadillac`, `Cutti`, `Sweet`, `Ppotto`, `Lycopin-9`, eight in globe tomato, `Lovely 240`, `Dotaerang Dia`, `Cupirang`, `Dotaerang Master`, `Super Dotaerang`, `Dotaerang Season`, `Miroku`, `Hoyong`, and three in root stock, `Special`, `Fighting`, and `Magnet`.

Studies on HG Type of Heterodera glycines in Korea

Thirteen soybean cyst nematode (SCN) (Heterodera glycines) populations collected in Korea were examined in their HG type by their reproductivity on 7 Plant Introduction indicators for the identification of HG type. Six HG types were identified, HG type 0, 2, 5, 2.5, 1.2.7, and 2.5.7. HG type 2.5 was the most frequent (4 samples, 30.8%), followed by HG type 2.5.7 (3 samples, 23.0%). About 76.9% of SCN populations were reproduced on PI 88788, followed by PI 209332 (61.5%), PI 548316 (‘Cloud’) (30.8%), and PI 548402 (‘Peking’) (7.7%). No population could reproduce on PI 90763, PI 437654, thus, they could be used for resistant source for developing SCN resistant soybean in Korea.

Plant Parasitic Nematodes in Soybean in Korea and Their Importance Rating

Plant parasitic nematodes were isolated from 274 soil samples collected from soybean fields in Korea. Nematode importance rating in soybean is proposed based on this study and by reviewing other reports. Soybean cyst nematode, Heterodera glycines is the most important nematode species and rated as 1 st because it detected from 38%(range 25-51%) of soil samples with high density except Jeju province. Root-knot nematode, Meloidogyne spp. is rated 2 nd and is more widely distributed in southern provinces, Gyeongnam, Jeonnam, and Jeju province (detection rate ranged 16-44%). Pratylenchus is rated 3 rd and is more frequently detected from northern provinces such as Gyeonggi and Gangwon (detection rate ranged 10-13%). Helicotylenchus is rated 4 th and is particularly important in Jeju province (detection rate is 62% and numbers averaged 571 nematodes/300cm 3 soil), which is the main production area for sprouting soybean in Korea. Tylenchorhynchus, Paratylenchus, Criconema, Criconemoide, Mesocriconema, Ogma, Xiphinema, Paratrichodorus, and Trichodorus occur in low frequency and density, thus they are rated to 5 th . We propose to delete following nematode genus from the list of soybean parasitic nematode in Korea because their parasitism on soybean is unconfirmed or negligible; Tylenchus, Aphelenchus, Aphelenchoides, Ditylenchus, Hirschmanniella immamuri, Basiria graminophila, Psilenchus, and Pseudhalenchus. Therefore, we revised 30 species in 16 genera as soybean parasitic nematodes in Korea. Importance rating is 1 st Heterodera glycines, 2 nd Meloidogyne spp., 3 rd Pratylenchus spp. and 4 th Helicotylenchus spp. especially in Jeju province.

Resistance of Sesame and Perilla Cultivars to Meloidogyne arenaria and M. incognita in Korea

뿌리혹선충(Meloidogyne spp.)은 전 세계적으로 농작물에 큰 피해를 미치는 선충인데 국내에서는 주로 시설재배지 작 물에 많이 발생되고 있다. 뿌리혹선충에 감염된 식물은 뿌 리에 혹이 형성되고, 이로 인하여 양분과 물의 흡수가 저해 되어 지상부에는 양분결핍 증상이 나타나고 결과적으로 수 확량이 감소하게 된다(Williamson과 Hussey, 1996). 또한 뿌 리혹선충은 양분과 수분의 흡즙에 의한 직접적인 피해뿐 만 아니라 선충의 침입에 의해 식물체에 상처를 발생시키 고 그 상처를 통해 토양에 서식하는 각종 세균, 곰팡이 등이 침입하여 각종 식물병을 유발하기도 한다(Park 등, 1995). 전 세계적으로 약 90종의 뿌리혹선충이 있는데(Perry 등, 2009), 국내에서 중요한 뿌리혹선충 4종은 고구마 뿌리혹선충 (Meloidogyne incognita), 땅콩 뿌리혹선충(M. arenaria), 당근 뿌 리혹선충(M. hapla), 자바니카 뿌리혹선충(M. javanica)이다. 국내 남부 시설재배지에는 주로 M. incognita와 M. arenaria가 분포하고 있으며 그 분포 비율은 각각 45%와 55%이다(Kim 등, 2001b). 시설재배지에서는 동일 작물의 연작재배로 인해 토양 기 생선충의 밀도가 증가하여 선충 피해가 만연하고 있는데 뿌 리혹선충의 피해로 인하여 선충 침입에 의한 상처 부위에 이차적인 토양 전염성병의 발생을 유발하고 수확 후기부터 작물이 고사하고 있다. 작물이 고사한 포장에는 다음해 선 충 피해를 막기 위해 윤작, 객토 등 여러 가지 처리를 하고 있

Survey of Nematodes in Coniferous Bonsai in Korea

Bonsai refers to trees growing in pots for people who enjoy watching them. It is considered as an elegant hobby for generations. Today, bonsai is an export commodity. It has become a high-value product. Japanese bonsai is renowned worldwide. However, Japanese bonsai is suffering due to aged technicians, high-wages, and avoidance of labor-intensive growing for bonsai by young people. China is supplying a huge amount of low quality bonsai to the world market based on large acreage and low wages. If Korean bonsai gardeners could supply high quality bonsai at affordable prices, they could have a competitive edge in the export market of bonsai. For bonsai exports, EU and the United States require that bonsai should be grown in certified gardens that meet their specific standards. Recently, EU and other countries have strengthened nematode inspection for bonsai during the quarantine process. To promote bonsai exports, bonsai should be free of plantparasitic nematodes. There are 1,500 plant-parasitic nematodes. They cause crop losses with estimated economic value of about

Screening of Tissue Papers for Nematode Extraction for the Baermann Funnel Method

1,180 billion worldwide. In Korea, 132 species in 42 genera and 12 families of plant-parasitic nematodes have been reported (Choi, 2001). However, bonsai nematodes have not been reported yet. Therefore, the objective of this study was to survey nematodes in bonsai gardens of Korea.

Effect of Density of Helicotylenchus dihystera on Growth of Solanum lycopersicum

The Baermann funnel method requires approximately four Kimwipe tissues for research a nematode count under a stereo microscope. To select more efficient and economical nematode extraction paper for nematode extraction, 15 different kinds of tissue papers were tested and compared with Kimwipe tissues. Nematode species used in the extraction efficiency tests include juvenile (J2) of Heterodera sp., J2 of Meloidogyne sp., Pratylenchus sp., Rhabditis sp., Acrobeloides sp., Panagrolaimus sp., Poikilolaimus sp. and Diplogasterida. The extraction efficiency varied between 42.0 to 88.8%. Considering costs, extraction efficacy, and clarity, the Pulling Kitchen Towel (Monalisa Co., Korea) is the best tissue, with clarity A, isolation efficiency of 69.4% (not significantly different compared to Kimwipe 1 ply 88.8%), and 1⁄2 costs per isolation of Kimwipe 2 ply.

Identification and Characterization of Entomopathogenic Fungi Isolated from Bemisia tabaci in Korea

A greenhouse experiment was conducted to examine the effect of initial population density (Pi) of Helicotylenchus dihystera on six commercial tomato cultivars. Two-week-old tomato seedlings of six commercial cultivars were transplanted in d-10-cm clay pot and was inoculated with to give 0, 0.02, 0.2, and 2 nematodes/g soil. Plants were grown in a greenhouse for 60 days. Root and plant weights were unaffected but plant height declined only at inoculum level of 2 nematodes/g soil. At the highest initial population density (2 nematodes/g soil), plant height of tomato cv. Poseidon was reduced by 24%. Tomato cv. Hoyong produced the most nematodes with 7.0 nematodes/g soil and the least was tomato cv. Miniheuksu with 2.2 nematodes/g soil.

Resistance of Soybean Cultivars to Heterodera glycines HG type 2.5 in Korea

Entomopathogenic fungi were isolated from Bemisia tabaci in an Oriental melon field, and their growth characteristics, factors related to a natural outbreak, and infectivity against Bemisia tabaci, Tetranychus urticae, and Frankliniella intonsa were investigated. The isolates had erect conidiophores bearing whorls of 4-6 phialides with a swollen base where cylindrical conidia of were attached. The isolates were identified as Isaria fumosorosea on the basis of morphological characteristics and an ITS sequence with 99% similarity. I. fumosorosea IFs-08 grew well on Sabouraud dextrose agar+yeast extract medium(3.2 mm/day/); it grew better at than at . The isolates of I. fumosorosea-IFs were highly infective and killed 93.9-96.7% B. tabaci, 84.9-92.0% T. urticae, and 81.5-84.4% F. intonsa in bioassay, whereas three isolates (Isaria tenuipes, Isaria farinosa, and Isaria fumosorosea) from KACC showed a low infectivity of 10-20%. To the best of our knowledge, this is the first report of I. fumosorosea isolated from B. tabaci in Korea.

New Cyst Nematode, Heterodera sojae n. sp. (Nematoda: Heteroderidae) from Soybean in Korea.

A total of 75 soybean cultivars developed in Korea was screened against soybean cyst nematode (SCN), Heterodera glycines HG type 2.5. Cysts developed on soybean cultivars ranged from 104 to 624 cysts per pot. There was no resistant cultivar but `Jangyeopkong`, `Saealkong`, `Miryangkong`, and `Mansukong` were moderately resistant; 33 cultivars were moderately susceptible and the other cultivars were susceptible. `Jangyeopkong`, `Saealkong`, `Miryangkong`, and `Mansukong` could be recommended for soybean fields infested with SCN until developing SCN resistant soybean.