Clover cyst nematode (Heterodera trifolii, CCN) is one of the important plantparasitic nematodes in the Republic of Korea, causing serious damage to Kimchi-cabbage in Gangwon province since 2017. Soil fumigants are the preferred choice for managing CCN. However, cabbage fields in Gangwon province have a slope, making it challenging to apply soil fumigants and use plastic mulch. Consequently, alternative materials should be developed for managing CCN. Nematicidal cover crops and resistant cultivars are among the alternatives. We conducted resistance screening of 82 white mustard (Sinapis alba) resources from a genebank at RDA against CCN for use as nematicidal cover crops or breeding materials. In the first assay (1st, 2nd, and 3rd pot experiments), 15 white mustard resources were selected, while others were susceptible to CCN. To confirm the reproducibility of resistance to CCN for 13 selected resources, the second assay was performed. As a result, five white mustard resource (IT297309, IT297312, IT302951, IT302953, IT302954) demonstrated resistance to CCN. These findings indicate the potential use of these five white mustard resources as nematicidal cover crops or for breeding cultivars of Kimchi-cabbage in Republic of Korea.

Southern root-knot nematode (SRKN, Meloidogyne incognita) is known to be responsible for annual economic losses of 38.2 million USD in cucumber cultivation in Korea. Nematicides are frequently used to manage SRKN in plastic greenhouses. A field experiment was conducted to assess the effect of a soil fumigant (dimethyl disulfide, DMDS) and a non-fumigant (fluopyram, FL) against SRKN during the winter fallow season in a greenhouse from October to December. Nematicidal efficacy was assessed at 43 days after treatment, and the root gall index was measured 4 months after transplanting cucumber seedlings. DMDS effectively reduced second-stage SRKN juvenile density with 91% control efficacy, while FL showed no control efficacy against SRKN. Root gall index values were significantly different (p=0.020) in DMDS treatment and controls at 1.0±0.00 and 4.3±0.58, respectively. This study showed that DMDS could be considered an effective nematicide for controlling SRKN in the fallow period in winter.

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.

본 연구는 국내 배추 주산단지 5지역을 대상으로 배추 재배에 활용되는 농업용수를 각 지역의 수확 시기에 채취 하여 위생지표세균(총대장균군, 대장균, 장구균)과 이화학 성분을 분석함으로써 농업용수의 수질의 오염도를 조사하기 위하여 수행되었다. 그 결과 지하수 보다 지표수에서 위생지표세균이 높은 수준으로 검출되었다. 지표수의 경 우 총대장균군 1.96-4.96 log MPN/100 mL, 지하수의 경우 0-3.98 log MPN/100 mL 수준이었다. 장구균의 경우 지표 수에서 95% (72/75), 지하수에서 22% (8/36) 빈도로 검출 되었으며, 대장균의 경우 지표수에서 100% (72/75), 지하수에서 22% (8/36) 빈도로 검출되었다. 위생지표세균과 이 화학성분의 상관관계를 조사한 결과, 지표수의 경우 대장균군과 대장균은 총인과 상관성을 보였으며, 장구균은 부유물질과 생물학적산소요구량에 상관성을 보였다. 지하수의 경우 위생지표세균은 부유물질과 화학적산소요구량에 상관성을 보였다. 본 연구의 결과는 엽채류 재배에 사용되는 농업용수의 미생물 기준을 설정하기 위한 기초자료 로 활용될 수 있을 것으로 판단된다.

Sugar beet cyst nematode (SBCN), Heterodera schachtii, is one of the important pests of sugarbeet growing area inthe world, especially in Europe, Canada and USA. SBCN has host in 23 plant families and the important crop host occursin two families; the Chenopodiaceae and Brassicaceae. Host crops include beets, mangolds, cabbage, spinach, brassicas,radish, mustard, and broccoli etc. In korea, SBCN was first detected in the highland Kimchi cabbage fields of easternGangwon-do, 2011. The obvious foliar symptom is poor plant stands and growth, wilting and yellowing. The most easilyrecognized sign of infection is the white to pale yellow and lemon-shaped adult female attached to roots. A survey ofBrassica spp. fields was conducted to determine the distribution of SBCN in Korea. The cyst nematode was only foundedin a restricted highland Kimchi cabbage fields in Gangwon-do. Damage from SBCN may be reduced by employing acombination of various management practies such as prevention of nematode infestation, crop rotation, SBCN resistanttrap crop, weed control and chemical control.

본 연구는 캄보디아에서 육성된 36개 벼 품종의 종실 및 이화학적 특성 등 분석을 통해 금후 캄보디아 고품질 벼 품종 개발과 쌀 수출증대에 필요한 기초자료를 얻고자 시험하였으며, 그 결과는 다음과 같다. 1. 캄보디아에서 육성된 벼 품종은 대부분이 감광성이며, 무 감광성은 조생종과 일부 중생종이였다. 2. 종실의 주요 특성 중 1,000립중의 범위는 24-31 g이었다. 중생종의 무 감광성이 31.4 g으로 높은 반면 만생종은 24.2 g으로 낮았다. 입장은 7.9 - 10.6 mm으로 모든 품종이 장립종이었다. 입폭은 1.77 - 2.03 mm로 품종간 차이는 없었다. 3. 도정된 벼의 특성 중 완전미의 비율은 31 - 66% 범위이며, 중생종 향미가 66.9%로 높았다. 반면 다른 품종은 50%이하를 보였다. 분상질립의 비율은 1.1 - 19.4% 범위로 중생종 향미가 1.1% 가장 낮은 반면 만생종이 3.5%로 높았다. 4. 단백질 함량은 7 - 8% 범위이고, 아밀로스 함량은 17.2 - 27.3% 범위였으며, 특히 중생종의 향미가 17.2%로 다른 품종에 비해 가장 낮았다.

한국에서 개발한 고추 9품종, 토마토 5품종을 대상으로 캄보디아의 고온 조건에서 차광재배를 통하여 적응품종을 선발하고 그 품종과 함께 재배기술을 수요자에게 보급함으로서 소득향상에 기여할 기초자료를 얻고자 본 연구를 수행한 바 그결과를 요약하면 다음과 같다.1. 고추 품종의 과폭은 최대 1.35cm (60%차광 Internet),최소 0.56cm(10%차광 Chili9) 로 나타났다 2. 고추 품종의 과장은 Asia Dan 4를 제외한 모든 품종에서10%, 60% 차광의 경우 무차광에 비하여 커지는 경향이었다.3. 고추의 과중은 0.9g (무차광 Asia Dan)에서 7.3g (60%Hot Asia)의 범위로 품종별, 차광별로 차이를 보였다.4. Chili 9를 제외한 고추품종에서 차광재배보다 무차광에서주당 과실수가 많았다. 특히 무차광일 경우 Asia Dan 2,Asia Dan 4, Asia Dan 24 등은 각각 55개, 40개, 41개 등으로 차광처리구 보다 많았다. Hot Asia, Hot Pia, Internet품종 등은 차광재배가 더 유리한 것으로 보였다. Asia Dan2, Asia Dan 4, Asia Dan 24 등은 노지재배가 더 유리할것으로 보였다.5. 토마토의 경우 10%와 60%차광의 과실수는 품종에 따라10개~36개의 범위를 보였다. 반면 무차광의 경우는 품종에따라 46~81개로 많았다. 특히 Hero110 과 Hera110의 경우10%차광, 60%차광처리에 비해 무차광일 경우 4배 이상 높은 수확량을 보였다.6. 토마토의 당도는 Asia Rio를 제외한 나머지는 무차광에서 높았다. 특히 Hero80은 다른 품종에 비하여 6.1 brix°를보여 월등하게 높았다.

During the survey of plant parasitic nematode of Citrus orchard in Korea, Paratrichodorus minor (Colbran, 1956) Siddiqi is founded from the soil of Citrus unshiu Markovich for the first time in Korea. The body length of females is 428.34~506.22 ㎛ long: a = 12.08~22.79, b = 4.02~5.02, V(%) = 38.46~60.68. The excretory pore is located near the base of esophagus. Additionally, the morphological characteristics on P. porosus (Allen, 1957) Siddiqi, 1974 recorded in 1976 on Korea is redescribed in detail.

This study was conducted to investigate occurrence and biodiversity of phytoparasitic nematodes in kiwifruit orchards in Korea. Soil samples were collected from 11 locations of Gosung, Goheung, Namhae, Bosung, Sacheon, Suncheon, Wando, Jangheung, Jeju, Jindo, Haenam from April to August, 2008. Phytoparasitic nematodes were found in 115 among 178 soil samples. The major genera of phytoparasitic nematodes on kiwifruit were Meloidogyne spp.(52.2%), Tylenchinae (42.1%), Tylenchus spp. (9.0%), Helicotylenchus spp. (9.0%) and Tylenchorhynchus spp. (6.7%). Ditylenchus spp., Hirschmaniella spp., Trichodorus spp. and Psilenchus spp. were also detected, even though their frequencies were very low. According to the cultivation period, the phytoparasitic nematodes were found as follows; 16.9% of soils under 5 years of kiwifruit cultivation, 10.7% 6~10 years, 23.0% 11~15 years, 3.9% 16~20 years and 5.6% over 21 years respectively. The frequency of phytoparasitic nematodes is higher in the open field (50.0%) than that in plastic houses (13.5%). The frequency of phytoparasitic nematodes was 36.5% in the field where vegetables were previously cultivated and 12.9% in the field where rice was previously cultivated.

Trophic groups and functional guilds were studied of soil nematodes from the soils of two abandoned mines in Ilkwang and Gunbuk, South Korea to compare nematode communities between the heavy metal contaminated soil and the nonheavy metal contaminated soil. No obvious correlation was found between the level of heavy metal and the total number of nematodes statistically. However the overall densities of bacterial, hyphal, omnivorous and predatory nematodes from the non-heavy metal contaminated soil was higher than those from the heavy metal contaminated soil. Also the densities of c-p 2, c-p 3, c-p 4 and c-p 5 nematodes were higher from the non-heavy metal contaminated soil than those from the heavy metal contaminated soil. MI, MI 2-5 and ΣMI 2-5 were higher, but there were no significant differences.

We amplified D1 and D3 expansion segments of the 28S ribosomal RNA from 10 Suanguina moxae populations found in Korea. The amplification of the D1-D3 expansion segments of 28S gene of all populations tested produced a single PCR product approximately 1.03kb in size, suggesting the lack of D1-D3 expansion region size polymorphism among populations. The secondary structure model of 28S expansion segments D2 and D3 for Subanguina Moxae was predicted based on free energy minimization with comparative sequence analysis and new sequence alignment was conducted based on predicted secondary structure model. The predicted model was compared with previous predicted models of plant and animal parasite nematode. This predicted secondary structure model will provide valuable information to allocate positional sequence homology and reconstruction of reliable phylogenetic trees.

차나무뿌리썩이선충(Pratylenchus loosi)이 국내에서 처음으로 전라남도 명암군과 제주도 남제주군의 차나무 뿌리와 주변 중에서 발견되었다. 차나무뿌리썩이선충의 두부주름은 2개이며 암컷의 길이는 433-646이고, a ＝ 29.1-37.5, b ＝ 5.1-6.4, c ＝ 15.0-21.3, vulva (%) ＝ 73.0-85.4였다. 수컷의 몸길이는 408-512 였으며 a ＝ 36.1-40.0, b ＝ 4.8-6.7, c ＝ 17.0-19.0, spicule ＝ 14.1-18.0였다. 구침의 길이는 11.6-18.0였으며, 측선의 갯수는 4개였다. 저정낭은 정자로 차 있으며, 모양은 둥근 고치모양 또는 직사각형 모양이다. 꼬리의 형태는 가늘고 끝이 둥글거나 뾰족하다.

This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and 30°C). Baranyi model was used as a primary order model for growth data. The maximum growth rate (μmax) and lag-phase duration (LPD) for each temperature (except for 10°C LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.