• 제목/요약/키워드: Dark spot

검색결과 123건 처리시간 0.026초

Incidences of Leaf Spots and Blights on Kiwifruit in Korea

  • Jeong, In-Ho;Lim, Myoung-Taek;Kim, Gyung-Hee;Han, Tae-Woong;Kim, Hong-Chul;Kim, Min-Ji;Park, Hyun-Su;Shin, Soon-Ho;Hur, Jae-Seoun;Shin, Jong-Sup;Koh, Young-Jin
    • The Plant Pathology Journal
    • /
    • 제24권2호
    • /
    • pp.125-130
    • /
    • 2008
  • Various kinds of leaf spots and blights were found in kiwifruit (Actinidia deliciosa) orchards on 2006 in Korea. Disease incidences were quite variable between open-field and rain-proof shelter. Rate of diseased leaves was recorded as about 70% at open-field orchards in late season but use of rain-proof vinyl shelters alleviated the disease incidences by 20%. Angular leaf spots appeared at early infection stage on June and several other symptoms were also recognized as the disease developed afterward. On September, brown leaf blights were the most frequent, followed by grayish brown ring spots, silvering gray leaf blights, zonate leaf blights, dark brown ring spots and angular leaf spots at open-field orchards. Four fungal species were frequently isolated from the disease symptoms. Phomopsis sp. was the most predominant fungus associated with the leaf spot and blight symptoms on kiwifruit, followed by Glomerella cingulata, Alternaria alternata and Pestalo-tiopsis sp. Phomopsis sp. was commonly isolated from angular leaf spots, silvering gray leaf blights, and zonate brown leaf blights. G. cingulata, A. alternata and Pestalotiopsis sp. were isolated from grayish brown ring spots (anthracnose), brown ring spots and zonate dark brown leaf blights. Typical symptoms appeared on the wounded and unwounded leaves, which were inoculated by each of Phomopsis sp., G. cingulata, and Pestalotiopsis sp., but A. alternata caused symptoms only on the wounded leaves.

재래종 팥의 작물학적 형질 특성 (Agronomic characters of Korean Adzuki Beans (Vigna angularis (Willd.) Ohwi & Ohashi))

  • 노창우;손석용;홍성택;이경희;유인모
    • 한국자원식물학회지
    • /
    • 제16권2호
    • /
    • pp.147-154
    • /
    • 2003
  • 우리나라에서 수집된 재래종 팥 361개의 작물학적 특성을 조사한 결과 수집재래종 팥의 초형은 직립형이 77.8%로 제일 많고 중간형이 15.3%, 만성형이 6.9%로 제일 적었다. 엽형은 원형, 타원형, 점선형 순으로 많았고 화색은 황색 이 89.5%로 가장 많았고 담황색 9.4%, 농황색 1.1% 순이었다. 종피색은 적색 60.6%, 회색 26.9%이며 그 외 녹색, 백색, 담흑색, 적지흑, 암지흑, 백지갈색 은 1.4∼3.3%로 매우 적었다. 개화일수는 69∼75일, 결실일수는 41∼50일, 생육일수는 111∼120일인 수집종들이 가장 많았다. 경장은 41∼60 cm에서 50,2%, 개체당 협수는 16∼20개에서 40.2%, 100립중은 8-10g이 30.5%로 가장 분포비율이 높았다.

흑전갱이, Carangoides ferdau의 형태적 특징 및 분자계통분류학적 위치 (Morphological Characteristics of the Blue Trevally, Carangoides ferdau (Perciformes: Carangidae) and its Phylogenetic Relationships among Korean Relatives)

  • 김준상;송춘복
    • 한국어류학회지
    • /
    • 제25권4호
    • /
    • pp.222-226
    • /
    • 2013
  • 수중사진으로만 보고되었던 흑전갱이 (Carangonides ferdau)에 관해서 제주도 연안에서 채집된 표본 2개체를 근거로 하여 형태적 특징을 상세하게 기재하였다. 이 종의 특징은 제2 등지느러미 전반부가 길고, 몸에 7~8개의 가로줄 무늬가 있으며 문장이 눈의 지름과 거의 유사하다는 점이다. 그리고 흑전갱이는 제주도 주변해역에 분포하는 노랑점무늬유전갱이 (C. orthogroammus)와 형태적으로 매우 유사하지만 몸통에 있는 가로줄무늬로, 몸통에 노란 반점을 가지는 노랑점무늬유전갱이와 쉽게 구분된다. 한편, cytochrome b 염기서열을 이용하여 작성한 분자계통수에서 흑전갱이와 노랑점무늬유전갱이, 그리고 채찍유전갱이와 미늘전갱이가 각각 계통분류학적으로 가장 가깝게 묶여서 자매군을 형성하였으며, 이들의 염기서열 차이(p-distance)는 각각 8.2%를 나타내었다.

Effect of NaOH Concentration on the PEO Film Formation of AZ31 Magnesium Alloy in the Electrolyte Containing Carbonate and Silicate Ions

  • Moon, Sungmo;Kim, Yeajin;Yang, Cheolnam
    • 한국표면공학회지
    • /
    • 제50권5호
    • /
    • pp.308-314
    • /
    • 2017
  • Anodic film formation behavior of AZ31 Mg alloy was studied as a function of NaOH concentration in 1 M $Na_2CO_3$ + 0.5 M $Na_2SiO_3$ solution under the application of a constant anodic current density, based on the analyses of voltage-time curves, surface appearances and morphologies of the anodically formed PEO (plasma electrolytic oxidation) films. The anodic film formation voltage and its fluctuations became largely lowered with increasing added NaOH concentration in the solution. Two different types of film defects, large size dark spots indented from the original surface and locally extruded white spots, were observed on the PEO-treated surface, depending on the concentration of added NaOH. The large size dark spots appeared only when added NaOH concentration is less than 0.2 M and they seem to result from the local detachments of porous PEO films. The white spots were observed to be very porous and locally extruded and their size became smaller with increasing added NaOH concentration. The white spot defects disappeared completely when more than 0.8 M NaOH is added in the solution. Concludingly it is suggested that the presence of enough concentration of $OH^-$ ions in the carbonate and silicate ion-containing electrolyte can prevent local thickening and/or detachment of the PEO films on the AZ31 Mg alloy surface and lower the PEO film formation voltage less than 70 V.

제주도 남부 연안해역에서 채집된 농어목 놀래기과 한국 첫기록종, Oxycheilinus bimaculatus (First Record of the Two-spot Wrasse, Oxycheilinus bimaculatus (Perciformes: Labridae) from the Southern Coastal Waters of Jejudo Island, Korea)

  • 김병직;안정현;김상길
    • 한국어류학회지
    • /
    • 제34권2호
    • /
    • pp.138-143
    • /
    • 2022
  • 우리나라 연안성 어류자원 미발굴 분류군 탐색을 위해 제주도 남부 연안해역에서 SCUBA를 이용한 수중조사 중 2015년 11~12월에 수심 약 17 m 부근에서 놀래기과 한국미기록종인 Oxycheilinus bimaculatus 3개체 (표준체장 50.6~67.7 mm)를 채집하였다. 본 종은 체형이 길쭉한 계란형으로 체고가 다소 낮아 두장보다 작은 점, 아래턱이 위턱보다 약간 긴 점, 눈의 후단과 가슴지느러미 후상방에 2개의 소형 흑색 반점이 있는 점, 성숙한 수컷의 꼬리지느러미 상부와 중앙의 기조가 실처럼 신장하는 점, 등지느러미 극조부 전반부가 검고, 등지느러미와 뒷지느러미 가장자리에 작은 흑색 반점이 산재하는 특징에서 동속 타종과 쉽게 구별된다. 본 종의 신한국명으로 체측에 2개의 흑색 반점이 있는 점에서 '두점긴주둥이놀래기'를 제안한다.

Preflight Calibration Results of Wide-Angle Polarimetric Camera (PolCam) onboard Korean Lunar Orbiter, Danuri

  • Minsup Jeong;Young-Jun Choi;Kyung-In Kang;Bongkon Moon;Bonju Gu;Sungsoo S. Kim;Chae Kyung Sim;Dukhang Lee;Yuriy G. Shkuratov;Gorden Videen;Vadym Kaydash
    • 천문학회지
    • /
    • 제56권2호
    • /
    • pp.293-299
    • /
    • 2023
  • The Wide-Angle Polarimetric Camera (PolCam) is installed on the Korea's lunar orbiter, Danuri, which launched on August 5, 2022. The mission objectives of PolCam are to construct photometric maps at a wavelength of 336 nm and polarization maps at 461 and 748 nm, with a phase angle range of 0°-135° and a spatial resolution of less than 100 m. PolCam is an imager using the push-broom method and has two cameras, Cam 1 and Cam 2, with a viewing angle of 45° to the right and left of the spacecraft's direction of orbit. We conducted performance tests in a laboratory setting before installing PolCam's flight model on the spacecraft. We analyzed the CCD's dark current, flat-field frame, spot size, and light flux. The dark current was obtained during thermal / vacuum test with various temperatures and the flat-field frame data was also obtained with an integrating sphere and tungsten light bulb. We describe the calibration method and results in this study.

녹두 발아 조해물질(阻害物質)의 이화학적(理化學的) 성질(性質) (Physico-chemical Characteristics of the Inhibitory Substance on the Germination of Mung Bean)

  • 김광현
    • 한국식품영양과학회지
    • /
    • 제14권1호
    • /
    • pp.57-60
    • /
    • 1985
  • 녹두 종자 발아억제물질을 생산하는 균을 동정한 결과 Streptomyces luteogriseus로 판정 되었으며, 본 저해물질의 순도검정을 위해 silica gel thin layer chromatography를 행한 결과 BuOH-HOAc-formic acid-water(15 : 12 : 3 : 10)와 BuOH-HOAc-water(4 : 1 : 5)의 용매게에서 각 Rf 치는 0.85와 0.92 의 단일 spot가 확인되었다. 또한 본 저해물질의 주요 radical을 조사해 본 결과 phenol기, pyrimidine 기, amono 기, 환원당 및 auxin은 함유되지 않았으며 단지 UV조사에 의해 형광을 나타내었다. 본 저해물질의 UV spectrum은 ${\gamma}^{H20}_{max}=252$ 였으며, IR spectrum 에서는 $3300{\sim}3500,\;2900{\sim}3000,\;1600{\sim}1700$$1400cm^{(-1)}$의 peak가 인정되었다.

  • PDF

Pseudomonas syringae pv. theae에 의한 차나무 갈색마름병 발생 (Occurrence of Brown Blight of Tea Plant Caused by Pseudomonas syringae pv. theae in Korea)

  • 최재을;차선경;육진아;최춘환;노일섭
    • 식물병연구
    • /
    • 제9권4호
    • /
    • pp.213-216
    • /
    • 2003
  • 2002년 봄, 순천시 비닐 하우스에서 육묘중인 차나무에 세균병이 발견되었다. 초기 병반은 신엽에 작은 수침상 병반이 나타났으며 갈색반점으로 변하였다. 이 병반은 점점 커졌으며, 중륵 또는 엽맥을 따라 신장하였으며 검은색으로 변하였고, 병든 잎은 쉽게 낙엽이 되었다. 병반으로부터 10균주를 분리하여 잎에 접종한 결과 자연 병반과 동일한 병징이 나타났다. 병원세균은 염색반응, 형태적 특성, colony 패턴, 생리적, 생화학적 반응에 따라 Pseudomonas syringae pv. theae로 동정되었다. 국내에서 이 균에 의한 차나무 세균병은 아직 보고되지 않았으므로 병명을 차나무 갈색마름병(brown blight)으로 명명할 것을 제안한다.

Altered Cultivar Resistance of Kimchi Cabbage Seedlings Mediated by Salicylic Acid, Jasmonic Acid and Ethylene

  • Lee, Young Hee;Kim, Sang Hee;Yun, Byung-Wook;Hong, Jeum Kyu
    • The Plant Pathology Journal
    • /
    • 제30권3호
    • /
    • pp.323-329
    • /
    • 2014
  • Two cultivars Buram-3-ho (susceptible) and CR-Hagwang (moderate resistant) of kimchi cabbage seedlings showed differential defense responses to anthracnose (Colletotrichum higginsianum), black spot (Alternaria brassicicola) and black rot (Xanthomonas campestris pv. campestris, Xcc) diseases in our previous study. Defense-related hormones salicylic acid (SA), jasmonic acid (JA) and ethylene led to different transcriptional regulation of pathogenesis-related (PR) gene expression in both cultivars. In this study, exogenous application of SA suppressed basal defenses to C. higginsianum in the 1st leaves of the susceptible cultivar and cultivar resistance of the 2nd leaves of the resistant cultivar. SA also enhanced susceptibility of the susceptible cultivar to A. brassicicola. By contrast, SA elevated disease resistance to Xcc in the resistant cultivar, but not in the susceptible cultivar. Methyl jasmonate (MJ) treatment did not affect the disease resistance to C. higginsianum and Xcc in either cultivar, but it compromised the disease resistance to A. brassicicola in the resistant cultivar. Treatment with 1-aminocyclopropane-1-carboxylic acid (ACC) ethylene precursor did not change resistance of the either cultivar to C. higginsianum and Xcc. Effect of ACC pretreatment on the resistance to A. brassicicola was not distinguished between susceptible and resistant cultivars, because cultivar resistance of the resistant cultivar was lost by prolonged moist dark conditions. Taken together, exogenously applied SA, JA and ethylene altered defense signaling crosstalk to three diseases of anthracnose, black spot and black rot in a cultivar-dependent manner.

MAGNETIC CVs AS A BRIGHT REPRESENTATIVE OF CLOSE BINARIES

  • QIAN, S.-B.;HAN, Z.-T.;ZHU, L.-Y.;LIAO, W.-P.;LAJUS, E. FERNANDEZ;ZEJDA, M.;LIU, L.;SOONTHORNTHUM, B.;ZHOU, X.
    • 천문학논총
    • /
    • 제30권2호
    • /
    • pp.175-178
    • /
    • 2015
  • Due to the lack of an accretion disk in a polar (magnetic cataclysmic variable, MCV), the material transferred from the secondary is directly accreted onto the white dwarf, forming an accretion stream and a hot spot on the white-dwarf component. During the eclipses, different light components can be isolated. Therefore, the monitoring of eclipsing polars could provide valuable information on several modern astrophysical problems, e.g., CVs as planetary hosting stars, mass transfer and mass accretion in CVs, and the magnetic activity of the most rapidly rotating cool dwarfs. In the past five years, we have monitored about 10 eclipsing polars (e.g., DP Leo and HU Aqr) using several 2-m class telescopes and about 100 eclipse profiles were obtained. In this paper, we will introduce the progress of our research group at YNOs. The first direct evidence of variable mass transfer in a CV is obtained and we show that it is the dark-spot activity that causes the mass transfer in CVs. Magnetic activity cycles of the cool secondary were detected and we show that the variable mass transfer is not caused by magnetic activity cycles. These results will shed light on the structure and evolution of close binary stars (e.g., CVs and Algols).