Geminiviruses are plant-infecting viruses with monopartite or bipartite single-stranded circular DNA genomes. They are known to be mediated by insects such as whiteflies, treehoppers, leafhoppers or aphids and can cause devastating plant diseases in a wide range of economically significant crops worldwide. In Korea, occurrence of geminiviruses were reported officially after the 2000s. Although Honeysuckle yellow vein virus (HYVV) and Sweet potato leaf curl virus (SPLCV) were identified from honeysuckle and sweet potato in 2004 and 2006 respectively, these viruses did not spread and cause much concern for geminiviruses. In 2008, Tomato yellow leaf curl virus (TYLCV) that has caused severe tomato production loss in many subtropical and tropical countries was first reported in tomato plants cultivated in Tongyeong. TYLCV rapidly spread through the country and has been continuously reported from tomato cultivating areas in Korea. In addition to TYLCV, Tobacco leaf curl virus and Sweet potato golden vein associated virus have occurred. In recent years, new geminiviruses including Papaya leaf curl Guangdong virus (PaLCGdV) and Euphorbia leaf curl virus (EuLCV) have been introduced. Newly emerging geminiviruses from tropical and subtropical countries are due to increased demand for various fruits and vegetables, and climate change. In addition, there are reports that some geminiviruses including TYLCV can be transmitted by infected seeds. Therefore it is important to study on epidemiology of virus introduction and spread among the countries and within country.

Scutellonema. brevistyletum was collected at soil around the roots of oriental melon (Cucumis melo L. var. makuwa Makino) at Seongju, Gyeongbuk in Korea. Scutellonema brevistyletum resembles to S. sorghi in having large number of longitudinal lines (16-18 vs 16 in S. sorghi), but differs by the areolated at level of scutellum(not areolated in S. sorghi), shorter tail length(9.1-13.3㎛ vs 16.2-35.7㎛ in S. soghi) and not long intestinal overlap rectum. S. brevistyletum differs from S. unum in having shorter stylet (24.5-28㎛ vs 29-32㎛ in S. unum) and basal lip not having longitudinal striae.

The measurements of Ditylenchus acutus is similar to Fortuner & Maggenti’s 1987 D. acutus (Khan, 1965) except the body length was much longer (L=0.65-0.71 mm vs. L=0.39-0.50 mm) and body width was thinner (a=40-49.2 vs. a=22-28). In addition, Ditylenchus myceliophagus was recorded for the first time in Korea. Thus, both species were described in this paper.

Rotylenchus arsenjevi are reported for the first time in Korea. The Korean species differs slightly by having a hemispherical lip region and a slightly shorter tail than the original description (c=38.2-68.7 vs 36-41). Male was founded firstly from Korea and described. Geocenamus adakensis were collected a second time from Korea at a different locality and habitat. The measurements were compared with original description and the firstly collected specimen in Korea.

Hemicycliophora minora Wu, 1966와 Pratylenchoides ivanovae Ryss, 1980를 국내 미기록종으로 보고한다. 현재 국내에는 Hemicycliophora속에서 총 5종, Pratylenchoides속에서 총 3종의 선충이 보고되었으며, 이들 종에 대한 검색표를 첨부하였다. 아울러 주사전자현미경을 이용하여 Pratylenchoides utahensis Baldwin, Luc & Bell 와 Rotylenchus feroxcis Eroshenko의 형태적 특징을 추가적으로 기록하였다.

새롭게 도입된 얌빈의 국내 재배기술 확립을 위하여 육묘조건, 적심, 적화, 재식밀도 등의 재배요인에 의한 생장과 수량반응을 조사한 결과는 다음과 같다. 얌빈은 P.E. 하우스내에 전열 온상을 설치하여 평균 22℃로 유지하여 30일(적산온도 650℃) 육묘하면 건전묘 생산이 가능하였다. 트레이 규격에 따른 출현 특성의 차이는 없으며, 셀 크기가 클수록 묘 생장량이 증가하지만 육묘효율, 이식작업의 편의성을 고려하여 128공 트레이가 적합하였다. 7월 하순에서 8월 상순에 120 ㎝ 높이에서 적심을 하면 수량이 23% 가량 많아지며 8월 하순에서 9월 상순 사이에 적화를 하면 괴경수와 괴경중이 증가하여 수량이 32% 가량 많아진다. 50 ㎝×30 ㎝로 정식하였을 때 관행 100 ㎝×30 ㎝보다 수량이 30% 증가하였다. 적심, 적화, 재식밀도 최적조합처리는 무처리에 비해 경제적으로 107%의 이익적인 요소가 발생하였다. 이상의 연구 결과 얌빈의 최적 재배기술 적용을 통해 국내에서 새로운 소득 작목으로서 유망할 것으로 판단된다.

Amaranth (Amaranth caudatus) is attracting attention as a preference crop in Gyeongsangbuk-do province. To determine its growth potential and cultivation requirements, we investigated its growth characteristics, dry matter productivity, and grain yield according to the growing period. Growth and dry matter productivity were significantly higher for plants that were sown on May 10th when the temperature was the highest, whereas the yield was significantly higher for plants that were sown on April 10th. Amaranth grain yield ranged from 96 to 243 kg according to the sowing date and cultivation year. The optimum harvest time for plants that were sown on April 10th, May 10th, and June 10th were 120, 110, and 110 days after seeding, respectively. The mean temperature and growing period had a significant quadratic function with yield. Based on these equations, the optimum growing temperature was estimated as 20.6℃ and the optimum growing period as 104-119 days after seeding.

This study was conducted to elucidate the photosynthetic response to the environment and establish optimum cultivation conditions for the Korean endemic plant, Aster koraiensis. Photosynthetic characteristics according to growth stage, light, CO2, and soil water potential were investigated. During the first year of transplanting, photosynthetic rates were drastically increased until June, after which they slowly declined, During the second year, photosynthetic rates declined throughout the entire growth period. The highest level of light compensation point was shown the early growth stage. Photosynthetic rates affected by intercellular CO2 concentration were maintained or decreased over the CO2 saturation point. The lowest CO2 compensation point was 16.1 μmol･mol -1 during March. The morphological changes of leaves were observed due to shading with chlorophyll contents increasing. Photosynthetic rates were higher at 0% and 50% shading treatments than at 75%. There were rarely any morphological changes of leaves due to soil moisture, however, changes to leaf compactness were observed. Photosynthetic rate, apparent quantum yield, and respiration rate increased, whereas water use efficiency decreased over -25 kPa of soil moisture.