• Asian-Australasian Journal of Animal Sciences
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• 제5권2호
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• pp.329-335
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• 1992

Degradation of rice straw was observed to be higher (p<0.01) in the buffaloes than in cattle. At 48 h, the dry matter (DM) loss of straw for buffaloes was 53.6 0.8% and that for cattle was 48.7 2.6%. Palm press fibre (PPF) was poorly degraded in the rumen of both animal species. A loss of about 21% DM was observed in both cattle and buffaloes after 48 h of incubation in the rumen. The pattern of bacterial and fungal colonization of straw and PPF seemed to be similar in both cattle and buffaloes. Microbial colonization was restricted by plant structures like the silica crystals in both straw and PPF. The predominant bacteria colonizing both straw and PPF fragments were the rods. Eroded zones and digestion pits were pronounced in straw fragments after 1 h of incubation. The PPF fragments appeared undegraded even after 6 h of incubation. Fungal colonization of straw was rapid and extensive in both cattle and buffaloes. The sporangia observed in straw were mainly spherical or oval in shape, but fusiform sporangia with acuminate tip were predominantly seen in PPF fragments.

• The Plant Pathology Journal
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• 제19권6호
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• pp.288-290
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• 2003

Shoot blight of suckers of common lilac plants (Syringa vulgaris) was found in an apartment garden in Daegu, Korea. The causal organism was a species of Phytophthora, which was homothallic with paragynous antheridium. Oogonia were globose and measured 21.5-34.0 $\mu\textrm{m}$ with an average of 29.7$\pm$3.2 $\mu\textrm{m}$ in diameter. Oospores in oogonia were round, light orange brown when mature, mostly plerotic, and measured an average of 25.6$\pm$3 $\mu\textrm{m}$ in diameter. Antheridia were ovoid and around 11.7$\times$7.8 $\mu\textrm{m}$. Sporangia seldom formed on agar media but formed abundantly in water. Sporangia that formed in water were semipapillate, ovoid obpyriform, non-caducous, and 23.4-66.3$\times$17.6-37.1 $\mu\textrm{m}$ in dimension with I/b ratio of 1.46. The causal organism was identified as Phytophthora citricola Sawada on the basis of morphological characteristics. This is the first report of shoot blight caused by P. citricola Sawada in lilac suckers in Korea.

• The Plant Pathology Journal
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• 제19권6호
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• pp.291-293
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• 2003

Leaf spot and blight disease of tree peony (Paeonia suffruticosa Andr.) was found in an apartment garden in Daegu in May 2003 for the first time in Korea. The causal organism was identified as Phytophthora cactorum (Leb. And Cohn) Schroeter. The causal fungus was homothallic, and produced distinctively papillate, ovoid to subspherical, and caducous sporangia with pedicel. Sporangia that formed in water measured 23.4-42.9$\times$21.5-35.1 $\mu\textrm{m}$ in range with an average of 35.3$\pm$4.6${\times}$26.9$\pm$36.0 $\mu\textrm{m}$, I/b ratio=1.31, papillae approximately 3.7 $\mu\textrm{m}$ high, and pedicels 2.8 $\mu\textrm{m}$ long. Oogonia were spherical and 21.5-37.1 $\mu\textrm{m}$ in diameter with an average of 29.6$\pm$4.9 $\mu\textrm{m}$. Oospores were spherical, mostly plerotic, and light orange brown when mature, and measured 19.5-31.2 $\mu\textrm{m}$ in diameter with an average of 25.2$\pm$4.4 $\mu\textrm{m}$. Antheridia were almost ovoid or club-shaped and 1l.7-15.6$\times$9.8-11.7 $\mu\textrm{m}$ in size.

• The Plant Pathology Journal
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• 제29권1호
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• pp.87-92
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• 2013

This study was conducted to determine the Phytophthora rot resistance of 514 accessions of watermelon germplasm, Citrullus lanatus var lanatus. About 46% of the 514 accessions tested were collections from Uzbekistan, Turkey, China, U.S.A., and Ukraine. Phytophthora capsici was inoculated to 45-day-old watermelon seedlings by drenching with 5 ml of sporangial suspension ($10^6$ sporangia/ml). At 7 days after inoculation, 21 accessions showed no disease symptoms while 291 accessions of susceptible watermelon germplasm showed more than 60.1% disease severity. A total of 510 accessions of watermelon germplasm showed significant disease symptoms and were rated as susceptible to highly susceptible 35 days after inoculation. The highly susceptible watermelon germplasm exhibited white fungal hyphae on the lesion or damping off with water-soaked and browning symptoms. One accession (IT032840) showed moderate resistance and two accessions (IT185446 and IT187904) were resistant to P. capsici. Results suggest that these two resistant germplasm can be used as a rootstock and as a source of resistance in breeding resistant watermelon varieties against Phytophthora.

• Journal of Microbiology
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• 제37권1호
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• pp.27-34
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• 1999

Two fractions with unusual antifungal activity that suppress asexual sporulation of several fungi were obtained from culture filtrate of Pseudomonas aeruginosa and were partially purified through the repeated silicagel flash column chromatographies. The sporulation-suppressive actions of these fractions in Aspergillus nidulans, Rhizopus stolonifer, and Coprinus cinereus, were analyzed by light and electron microscopes. The germination ability of the spores produced in the presence of these fractions were also checked to determine the persistent effects of these antifungal substances on the next generation. Light microscopic observation of developing sporangia of R. stolonifer grown in the presence of both fractions revealed that the significant number of sporangia failed to reach maturity, and frequently, uncontrolled growths of hyphae and rhizoids from the sporangiophores were found. In A. nidulans addition of these fractions appeared to cause different classes of morphological abnormality in conidia development, which included aborted formation of conidiogenous cells from the apex of conidiophores and enhanced hyphal growths either at the tip or middle of the conidiophores. Germination abilities of spores obtained from the cultures grown in the presence of antifungal fractions were 40∼60% in Aspergillus, 50∼80% in Coprinus (thallic spores), and 30∼40% in Rhizopus compared to those of normal spores.

• 식물병연구
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• 제20권1호
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• pp.50-53
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• 2014

2012년 태안백합시험장 포장에 재배중인 절화 백합에서 이상증상이 발생하였다. 처음 병징은 토양 지제부의 줄기가 물러지고 점차 위쪽으로 진전되면서 결국 잎을 포함한 식물체 전체 적가 빠르게 부패되었다. 병원균의 균사생육 적온은 $25^{\circ}C$이며 PDA상에 왕성하게 생장하였으며, 갈색의 균총과 검은색의 포자낭을 형성하였다. 포자낭경은 초기에 흰색에서 점차 회색으로 되었으며 포자낭을 균사 끝에 형성하였고, 폭은 $6-10{\mu}m$이었다. 포자낭은 처음에 흰색에서 나중에 검은색으로 되었고, 모양은 반구형으로 크기는 $87-116{\mu}m$이었다. 포자낭포자는 담갈색으로 단포이며, 구형 또는 타원형으로 대부분 불규칙하며, 크기는 $4-8{\mu}m$이었다. 이상과 같이 병원균의 균학적 특징, ITS 염기서열 분석, 병원성 검정 결과 본 병해는 Rhizopus oryzae에 의한 백합 무름병으로 명명할 것을 제안한다.

• Weed & Turfgrass Science
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• 제5권1호
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• pp.17-22
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• 2016

장성지역 잔디 재배지에서 총생 증상의 들잔디가 발생하였다. 총생 증상의 들잔디는 작고 다발형태로 유의한 형태적인 변화를 보였고, 병징은 여러 개의 잎이 짧은 포복경 마디에 무더기로 발생되어 빗자루처럼 총생 형태를 보였으며, 총생 형태의 잔디는 잎이 황화되면서 연녹색이나 노란색을 띄었다. 총생 증상을 보이는 들잔디는 건전한 들잔디에 비해 포복경 1개 마디당 약 5.8배 이상의 잎이 발생하였다. 또한 과도한 지상부 생육으로 인해 포복경과 지하부 생장이 저조하였다. 총생 병징의 들잔디를 채집하여 병원균을 배양한 후 관찰한 결과 포자낭의 모양은 레몬모양이었으며, 포자낭 축의 끝이 뾰족하게 튀어나와 있었고, 크기는 $60{\sim}96{\times}42{\sim}51{\mu}m$로 관찰되었다. 이는 Sclerophthora macrospora 병원균이 형성하는 포자낭의 균학적 특징과 유사하였고, 봄과 가을에 병징을 확인할 수 있었다. 따라서 본 연구를 통하여 국내 잔디 재배지 총생 증상에 대한 기초적인 자료를 제시하고자 한다.

• 식물병연구
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• 제7권1호
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• pp.8-10
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• 2001

1998년 경기도 고양시의 분화용 칼랑코에(Kalanchoe sp.)재배농가에서 줄기 하부가 검게 썩으며 급격히 시드는 증상으로부터 병원균을 분리.동정한 결과 Phytophthora nicotianae로 동정되었다. 병원균의 형태적 특성은 뚜렷한 유두돌기를 가진 유주자낭을 형성하였고, 원형~rPfis형이며 크기는 20~48$\times$24~64$\mu\textrm{m}$였고, 구형의 후막포자를 다량 형성하였다. 배양적 특성은 V8 juice agar와 corn-meal agar에서는 풍부한 균사를 형성하였으며, PDA에서는 전형적인 거미집 형태로 자라는 특성을 보였다. 생육온도범위는 최저 1$0^{\circ}C$, 최고 37$^{\circ}C$, 최적온도는 3$0^{\circ}C$였다. \\\"Florus\\\"를 비롯한 14개 칼랑코에 주요 재배품종에 대한 병원성검정을 실시한 결과 품종에 따라 저항성의 차이가 있었다.의 차이가 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제5권2호
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• pp.323-327
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• 1992

An experiment was conducted to determine whether there were any apparent differences in the microbial population, colonization pattern and digestion of guinea grass in situ, between cattle and swamp buffalo. Percentage losses in dry matter (DM), nitrogen (N) and neutral detergent fibre (NDF) of guinea grass were significantly (p<0.01) higher when incubated in the rumen of buffalo than in cattle. Buffalo also showed significantly (p<0.05) faster degradation rates than cattle for each grass component (DM, N, DNF). Light microscopy and SEM examination of the incubated grass materials showed that there were no apparent differences in the pattern of bacterial and fungal invasion and colonization of the grass materials between cattle and buffalo. Attachment of bacteria and fungal zoospores on the grass fragments occurred at 15 min after rumen incubation. After 3 h of rumen incubation, dense population of bacteria was observed in the thin-walled mesophyll and parenchyma tissues, whereas root-like fungal rhizoids were observed in both thin-walled and thick-walled cells. By 6 h, eroded zones were apparent in the thin-walled tissues and in thick-walled tissues with profuse rhizoids. After 24. 48 and 72 h of rumen incubation, most thin-walled tissues were degraded leaving mostly the thick-walled tissues. The predominant bacteria were the curved rods resembling Butyrivibrio sp., the thick rods resembling Fibrobacter sp., the diplococcoids resumbling Ruminococcus sp. And spirochetes. Fungi were predominantly those with spherical or oval sporangia. Fusiform sporangia with acuminate apices which resembled Ruminomyces sp. Were of lesser occurrence. Few protozoa were found on the grass fragments at all incubation times.

• 한국식물병리학회지
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• 제14권5호
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• pp.402-407
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• 1998

Phytophthora rot on jujube fruit has occurred at several cultivation areas in Kyung-buk and Kyung-nam provinces. Symptoms consisted of brownish to reddish rot on fruits resulting in early drop or mummification. The causal fungus isolated from infected fruits and adjacent leaf stalks was identified as Phytophthora citricola, which has never been reported in Korea. Sporangia were semi-papillate, noncaducous and highly variable in shapes. Plerotic oospores with paragynous antheridia were abundant is single cultures. Sporangia of two isolates were measured as 38-76$\times$20-40 ${\mu}{\textrm}{m}$ and averaged 51.4$\times$27.0 and 55.6$\times$36.0 ${\mu}{\textrm}{m}$. Oogonia were ranged from 26 to 36 ${\mu}{\textrm}{m}$ and averaged 31.3 and 32.0 ${\mu}{\textrm}{m}$. Colony pattern was slightly radiated with sparse aerial mycelia on common media. Minium, optimum and maximum temperatures for mycelial growth were recorded at 7, 25, and 32$^{\circ}C$, respectively. Among tested media, 10% V8A was the best and $25^{\circ}C$ was better than 15$^{\circ}C$ for oospore formation of the fungus. The jujube isolates of P. citricola were readily differentiated from other closely related species in the genus, namely; P. nicotianae, P. citrophthora, P. cactorum, P. capsici, and P. plalmivora on the basis of PCR-RFLP of r-DNA. The fungus showed strong pathogenicty to jujube, apple, pear, orange, persimmon and eggplant, and relatively weak to citron, tomato, pepper and cucumber. In this study, P. citrocola is firstly identified and jujube fruit rot caused by the fungus is recorded as a new disease in Korea.