• Mycobiology
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• 제38권2호
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• pp.137-143
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• 2010

The production of conidia of entomopathogenic Beauveria bassiana by solid-state fermentation was studied for the development of a biocontrol agent against aphid Myzus persicae. The optimal conditions for conidia production on polished white rice were 40% moisture content, $25^{\circ}C$ culture temperature, 2-day-old seeding culture grown in 3% corn meal, 2% rice bran, 2% corn steep powder medium, initial conidia concentration of $10^7$ conidia/g in the wet rice, 10% inoculum size, and use of a polyethylene bag as a container. The polyethylene bag containing inoculated rice was hand-shaken every 12 hr during fermentation. Using optimal conditions, the maximum conidia production obtained was 4.05 g conidia/100 g dry rice after 14 days of cultivation, a rate 2.83 times higher than conidia yield of pre-optimization.

• The Plant Pathology Journal
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• 제33권1호
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• pp.75-79
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• 2017

The causal fungus of pear scab, Venturia nashicola, grows slowly and rarely produces conidia on artificial media in the laboratory, but it produced conidia on the Cheongah medium containing Cheongah powder. V. nashicola grew too slow to produce conidia until 15 days after cultivation but produced conidia with $4{\time}10^4$ conidia/plate 30 days after cultivation on the Cheongah medium containing 1% Cheongah powder. V. nashicola showed a peak production of conidia with $4.5{\times}10^5$ conidia/plate 60 days after cultivation on the carrot medium containing 2% carrot powder, one of the constituents of Cheongah powder. The carrot medium is considered to be the best medium to obtain conidia of V. nashicola in the laboratory until now. This is the first report on the development of a suitable medium for conidia production of V. nashicola, as far as we know.

• Mycobiology
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• 제42권4호
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• pp.346-352
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• 2014

Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide, because of its increased resistance to some insecticide groups. As an alternative control agent, we selected an Isaria javanica isolate as a candidate for the development of a mycopesticide against the Q biotype of sweet potato whitefly. To select optimal mass production media for solid-state fermentation, we compared the production yield and virulence of conidia between 2 substrates (barley and brown rice), and we also compared the effects of various additives on conidia production and virulence. Barley was a better substrate for conidia production, producing $3.43{\times}10^{10}$ conidia/g, compared with $3.05{\times}10^{10}$ conidia/g for brown rice. The addition of 2% $CaCO_3+2%$ $CaSO_4$ to barley significantly increased conidia production. Addition of yeast extract, casein, or gluten also improved conidia production on barley. Gluten addition (3% and 1.32%) to brown rice improved conidia production by 14 and 6 times, respectively, relative to brown rice without additives. Conidia cultivated on barley produced a mortality rate of 62% in the sweet potato whitefly after 4-day treatment, compared with 53% for conidia cultivated on brown rice. The amendment of solid substrate cultivation with additives changed the virulence of the conidia produced; the median lethal time ($LT_{50}$) was shorter for conidia produced on barley and brown rice with added yeast extract (1.32% and 3%, respectively), $KNO_3$ (0.6% and 1%), or gluten (1.32% and 3%) compared with conidia produced on substrates without additives.

• 한국균학회지
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• 제19권1호
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• pp.27-31
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• 1991

국내외에서 수집된 10종의 느타리버섯 균사를 버섯 완전 배지에 배양한 후 균사체에 형성된 분생자(分生子) (conidia)를 관찰 하였다. 느타리버섯(P. ostreatus), 사철느타리버섯(P. florida), 노랑느타리버섯(P. cornucopiae), 맛느타리버섯(P. sapidus), 여름느타리버섯(P. sajor-caju), 분홍느타리버섯(P. salmoneostramineus) 외에 P. dryinus, P. eryngii, P. pulmonarius, 및 P. cystidiosus 균사에서 conidia가 형성되었다. Conidia 형태는 구형과 타원형의 2가지였고 2핵 균사체 뿐만 아니라 1핵 균사체에서도 conidia를 형성하였다. Conidia는 버섯 완전 배지에서 관찰되었으나 버섯 최소 배지에서는 관찰하지 못하였으며 담자포자에 UV를 처리하여 conidia를 형성하지 못하는 변이균주를 선발하였다.

• Mycobiology
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• 제36권3호
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• pp.183-189
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• 2008

The production of aerial conidia of Lecanicillium lecanii 41185, a highly virulent fungus, by solid-state fermentation was studied for use as a biocontrol agent against aphids. Among several agro-industrial solid media, steamed polished rice was found to produce the highest amount of aerial conidia. The optimal conditions for aerial conidia production were determined to be a 28.5% moisture content in the rice, 25$^{\circ}C$ culture temperature, rice pH of 6.0, 75% ambient relative humidity, 4-dold seeding culture, 0.6% $KNO_3$, and 12 d of culture time. The conidia yield increased from $5.7\times10^9$ conidia/g polished rice to 18.2 $18.2\times10^9$ conidia/g polished rice following application of these optimized conditions.

• The Plant Pathology Journal
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• 제18권6호
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• pp.328-332
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• 2002

Wheat samples showing typical spot blotch symptoms on stems and sheaths were collected from the field after physiological maturity, and were sealed in paper bags and stored in the laboratory at room temperature to study the survival of Bipolaris sorokiniana conidia on wheat straw. The materials were observed at monthly intervals to assess the conidia viability during storage. After 4 months, the frequency of individual conidia already present on wheat straw at the time of sampling was reduced and appeared to be progressively replaced by the formation of round structures consist-ing of conidia aggregates. After 5 months, distinct, individual conidia were no longer detected, and only 'clumps of conidia' were observed. These dark black aggregates or 'clumps of conidia’measured 157-170$\mu\textrm{m}$ in diameter and were grouped into boat-shaped olivacious conidia showing thick wall and measuring 50-82$\times$20-30$\mu\textrm{m}$. The germination was unipolar and below 0.5%, suggesting the occurrence of dormancy, In contrast, individual conidium produced on wheat during the growing season were 96-130$\times$16-20$\mu\textrm{m}$, slightly curved, hyaline to light pale, and euseptate with a bipolar germination reaching 98-100%. Bipolaris sorokiniana conidia produced on PDA were 55-82$\times$20-27$\mu\textrm{m}$, tapered at both ends, dark brown to olivacious, distoseptate, showed up to 1% germination, and were predominantly unipolar. Results of the present study suggest that B. sorokiniana conidia belonged to two different physiological categories corresponding to the pathogen's infection phase and its survival, respectively. The infection phase is characterized by a high germination percentage as opposed to the survival phase harboring apparent dormancy.

• 아시안잔디학회지
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• 제18권4호
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• pp.221-229
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• 2004

경북지방에서 분리한 곤충병원성곰팡이 Beauveria bassiana와 Metarhizium anisopliae를 이용하여 나비목 해충인 거세미나방 (Agrotis segetum), 배추흰나비 (Artogeia rapae), 도둑나방 (Mamestra brassicae), 배추좀나방(Plutella xylostella), 파밤나방 (Spodoptera exigua), 담배거세미나방 (S. litura)의 생물적 방제 가능성을 알아보기 위하여 실험한 결과, 거세미나방 2$\cdot$3령충에 대하여 B. bassiana와 M. anisopliae의 반수치사농도 ($LC_50$)는 접종7일 후에 각각 $4.3\times10^6\;conidia/m\ell$와 $2.4\times10^5\;conidia/m\ell$였다. 배추흰나비 2$\cdot$3령충에 대한 B. bassiana와 M. anisopliae의 $LC_50$는 접종 7일 후에 각각 $1.2\times10^7\;conidia/m\ell$와 $5.2\times10^6\;conidia/m\ell$였다. 도둑나방 2$\cdot$3령충에 대한 B. bassiana와 M. anisopliae의 $LC_50$는 접종 7일 후에 각각 $1.5\times10^6\;conidia/m\ell$와 $9.7\times10^5\;conidia/m\ell$였고, 배추좀나방 2$\cdot$3령충에 대한 B. bassiana와 M. anisopliae의 $LC_50$는 각각 $3.0\times10^6\;conidia/m\ell$와 $1.4\times10^6\;conidia/m\ell$였다. 파밤나방 2$\cdot$3령충에 대한 B. bassiana와 M. anisopliae의 $LC_50$는 접종 7일 후에 각각 $6.3\times10^6\;conidia/m\ell$와 $2.6\times10^6\;conidia/m\ell$였고, 담배거세미나방 2$\cdot$3령충에 대한 B. bassiana와 M. anisopliae의 $LC_50$는 각각 $1.6\times10^7\;conidia/m\ell$와 $3.4\times10^6\;conidia/m\ell$였다.

• 미생물학회지
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• 제13권2호
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• pp.45-50
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• 1975

Uptake of $^{14}C$-sorbose and $^{14}C$-3-O-methylglucose by ungerminated conidia of Neurospora crassa was measured by means of the millipore filter technique. Initial rates of jptake of both sorbose and 3-O-methylglucose show a marked dependence optimal pH for uptake of both sugars is close to 4.75. When ungerminated conidia are "starved" with buffer for a prolonged period of time prior to assaying their transport capacity and mycelia, no de-repression of the glucose-repressible sugar transport system is effectuated in contrast to the findings for germinated conidia.d conidia.

• 한국식물병리학회지
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• 제11권3호
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• pp.230-237
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• 1995

Airborne and waterborne ascospores and conidia of Botryosphaeria dothidea were collected in apple orchards at Suwon and Chunan in 1992 through 1994. Both waterborne and airborne spores were first detected in mid April to early May. Thereafter, spores were abundant in early June to late August and present until early December. Rainwater collections contained much more conidia than ascospores during the apple growing seasons. Airborne ascospores catches, which were also detected on humid days without measurable rainfall, were much more than airborne conidia catches. High amounts of ascospores were detected in early times of apple growing season, whereas most conidia catches occurred in later times of the season. The number of waterborne conidia and airborne ascospores was positively correlated with mean daily maximum, minimum, and average air temperatures during the trapping periods (p=0.01). However, no significant correlation was found between the number of spores and the total precipitation during the trapping periods.

• Mycobiology
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• 제33권2호
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• pp.118-120
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• 2005

Most commonly occurring predacious fungus Arthrobotrys oligospora showed great variation in size and shape of conidia on some media. The formation of larger conidia was recorded on beef extract and nutrient agar media. The length of conidia in Richard's YPSS, Sabouraud's, PDA and com meal agar media was of medium size while smaller conidia were produced on Czapek's, Jensen's, Martin's medium. Maximum width of conidia was recorded on YPSS medium followed by Sabouraud's medium. The average size of spores on nematode infested com meal agar medium was slightly increased than those on com meal agar medium.