• 한국균학회지
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• 제38권1호
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• pp.75-79
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• 2010

2006년부터 2007년까지 벼키다리병균을 수집하여 25개 균주의 prochloraz와 benomyl + thiram에 대한 약제저항성을 검정하였다. 공시한 균주 중, 대부분의 균주가 감수성이었으나 prochloraz에 대한 약제저항성 균주는 6개로 조사되었고, benomyl + thiram에 대해서는 3개 균주가 저항성을 나타내었다. 이 중 CF245, CF249, CF337은 공시약제 모두에 대해 저항성이었다. 감수성 균주간 교배 및 감수성, 저항성 균주간 교배를 통해 얻어진 후대균주를 분리하여 온도별 균사 생장율과 약제에 대한 반응을 조사하였다. 온도별 균사 생장은 감수성 균주간 교배(CF202 $\times$ CF232)에서는 모균주와 비슷하였으나, 감수성과 저항성 균주간 교배(CF179 $\times$ CF337)에서는 모균주에 비해 후대균주의 균사생장이 빠른 것으로 나타났다. 공시약제에 대한 반응은 약제에 따라 모균주와 다른 양상을 나타내었다. Prochloraz의 경우, 감수성균주인 CF202 $\times$ CF232의 후대균주에서 감수성과 저항성의 분포비율이 86 : 14로 나타났고, 감수성과 저항성 균주인 CF179 $\times$ CF337의 후대균주에서는 78 : 22로 나타났다. Benomyl + thiram의 경우, CF202 $\times$ CF232의 후대균주는 모두 감수성인 것으로 나타났으며, CF179 $\times$ CF337의 후대균주에서는 35 : 65로 조사되었다.

• 생명과학회지
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• 제18권10호
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• pp.1355-1359
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• 2008

내생성 진균류는 초본류의 식물체 내에 주로 서식하며, 식물의 병원균으로부터 숙주를 보호할 뿐만 아니라, 식물 생육에 유리하게 작용하는 다양한 대사 산물을 생산한다. 매우 흔히 접할 수 있는 사구식물의 뿌리로부터 49종의 균류를 분리하여 식물 생장 촉진 활성이 있는 균주를 선별하였다. 결과적으로 37균주(75.5%)는 awito-c 벼의 생육을 촉진하였으며, 11균주(22.5%)는 생육을 저해하였으며, 1균주(2%)는 생육에 아무런 영향을 미치지 않았다. Gibberella fujikuroi와 증류수 및 Czapek broth 배지를 control 로 사용하여 실험을 수행하였다. 결론적으로 사구식물 내생균류의 많은 부분은 숙주식물의 생육과 발달을 조장하는 대사 산물을 생산함을 알 수 있었다.

• 식물병연구
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• 제20권4호
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• pp.259-263
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• 2014

차아염소산나트륨의 벼 키다리병 종자소독제로서 활용 가능성을 구명하고자, 항균 활성 효과와 종자소독 효과를 연구한 결과, 차아염소산나트륨이 높은 항균 활성을 나타내어 $100{\mu}l/l$ 이상의 농도에서 균총이 형성되지 않았으며 $80{\mu}l/l$ 농도에서도 균 총형성이 현저히 낮았다. 벼 키다리병균 감염 벼 종자를 차아염소산나트륨 0.3% 농도로 8시간 침지 처리 시 종자소독효과가 90%로 높았다. 또한 차아염소산나트륨 0.5%, 0.3% 용액에 감염종자를 각각 12시간 처리하였을 벼 키다리병 발병율이 4.3%, 4.7%로 무처리 발병율 97.3%에 비해 현저히 억제되었으며, 유묘 출현율이 무처리 대비 29.1%, 26.9% 높았다. 그리고 벼 키다리병이 발생하여 자연 감염된 주남벼 종자를 사용하여 차아염소산나트륨 처리한 후 prochloraz 처리와, prochloraz를 처리한 후 차아염소산나트륨 처리의 종자 감염율이 각각 4.0%, 6.3% 로서 prochloraz 단독처리 13.7% 보다 낮은 경향을 보였으며, 벼 키다리병 발병율도 각각 3.7%, 8.3% 로 prochloraz 단독처리 14.3% 보다 낮았다. 아울러 차아염소산나트륨을 처리한 후 prochloraz를 처리한 것에서 더 높은 종자소독효과를 보였다.

• 한국작물학회지
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• 제53권4호
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• pp.417-420
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• 2008

2006년도에 생산한 일품벼 종자의 키다리병 이병종자와 건전종자를 사용하여 소독 방법별(관행-프로크로라츠 2,000배액 상온 24시간 침지후 침종 5일, 발아상-프로크로라츠 2,000배액 $33^{\circ}C$에서 48시간 침지 및 침종, 무처리-상온 6일 침종) 생육 특성과 수량 등을 분석한 결과는 다음과 같다. 키다리병 이병 종자의 소독 방법별 키다리병 발생율은 파종 후 10일째 무처리와 관행은 각각 76.0%, 5.0%였으나 발아 상 $33^{\circ}C$에서 프로크로라츠 2,000배액에 48시간 동안 소독 시는 발생하지 않았으며, 수확기 때는 발아상 소독시 발병율 3.3%로 관행 9.2%에 비해 낮아 효과적이었다. 수수는 발아상 소독시 30개/주였으나 관행이나 무처리시는 각각 27개, 24개로 적었다. 등숙율은 발아상 소독시 $81.3{\sim}80.3%$로서 관행 75.4%에 비해 $5.9{\sim}4.9%$ 향상 되었고 수량은 $512{\sim}517\;kg/1,000\;m^2$로 관행에 비해 $6{\sim}7%$ 증수되었다. 키다리병 이병 종자라도 발아상 이용 소독시 키다리병은 건전 종자와 비슷하게 발생하여 매우 효과적인 방법이라 할 수 있겠다.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.809-814
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• 2005

Gibberellins (GAs) play an important role in plant growth and development. Fifteen fungi were isolated from Physalis alkekengi var francheti plant roots, and among them, four isolates showed GA-production activity. A bioassay using waito-c rice was carried out with the culture fluid of the GA-producing fungi. The GA-producing fungi were cultured for 7 days in Czapek's liquid medium at $30^{\circ}C$, 120 rpm, under dark conditions. The culture broth was concentrated 30-fold and 10 ${\mu}l$ of that concentrate was applied to 2-leaf rice sprouts. The height of the rice seedlings treated with the culture fluid of isolate PA08 was 26 cm high, while that of the seedlings treated with the wild-type Gibberella fujikuroi was 13 cm high. As such, the plant growth-promoting activity exhibited by isolate PA08 was 2 times stronger than that exhibited by the wild-type G fujikuroi. The amounts of $GA_l,\;GA_3,\;GA_4,\;GA_7,\;GA_9,\;GA_{20}$, and $GA_{24}$ in the medium were measured using gas chromatography-mass spectrometry (GC-MS), and the quantities produced by isolate PA08 were 4.85 ng/ml, 4.79 ng/ml, 17.30 ng/ml, 6.01 ng/ml, 16.61 ng/ ml, 0.08 ng/ml, and 17.30 ng/ml, respectively. Isolate PA08 was also identified as Fusarium proliferatum KGL0401 by a genetic analysis of the nucleotide sequences of the internal transcribed spacer region of the ribosomal DNA.

• Journal of Microbiology and Biotechnology
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• 제31권11호
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• pp.1526-1532
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• 2021

Suaeda australis, Phragmites australis, Suaeda maritima, Suaeda glauca Bunge, and Limonium tetragonum in the Seocheon salt marsh on the west coast of the Korean Penincula were sampled in order to identify the endophytes inhabiting the roots. A total of 128 endophytic fungal isolates belonging to 31 different genera were identified using the fungal internal transcribed spacer (ITS) regions and the 5.8S ribosomal RNA gene. Fusarium, Paraconiothyrium and Alternaria were the most commonly isolated genera in the plant root samples. Various diversity indicators were used to assess the diversity of the isolated fungi. Pure cultures containing each of the 128 endophytic fungi, respectively, were tested for the plant growth-promoting abilities of the fungus on Waito-C rice germinals. The culture filtrate of the isolate Lt-1-3-3 significantly increased the growth of shoots compared to the shoots treated with the control. Lt-1-3-3 culture filtrate was analyzed and showed the presence of gibberellins (GA₁ 2.487 ng/ml, GA₃ 2.592 ng/ml, GA₉ 3.998, and GA₂₄ 6.191 ng/ml). The culture filtrate from the Lt-1-3-3 fungal isolate produced greater amounts of GA₉ and GA₂₄ than the wild-type Gibberella fujikuroi, a fungus known to produce large amounts of gibberellins. By the molecular analysis, fungal isolate Lt-1-3-3 was identified as Gibberella intermedia, with 100% similarity.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.91.1-91
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• 2003

Bakanae disease, caused by Gibberella fujikuroi (anamorph Fusarium moniliforme J. Sheldon), a typical seed-borne disease of rice occurs from nursery to paddy fields. Consequently, chemical seed disinfectants is the most efficient control method. Several seed treatment methods with various fungicides were attempted to inhibit disease. Spray and 24 hrs immersion of seeds using prochloraz emulsion reduced disease infection and the control value were 99.3 and 100％, respectively. In contrast, dressing to wet seeds thiophanate-methyl＋thiram wp and benomyl＋thiram wp reduced disease infection more effectively than 24 hrs immersion of seeds. However, dressing of carpropamid+imidacloprid＋fludioxonil wp to wet seeds did not reduced disease as well as wettable liquid of fludioxonil. The results suggest that the bakanae disease might be disinfected effectively by 24 hrs immersion of seeds in prochloraz emulsion and seed dressing of fungicides.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권6호
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• pp.544-549
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• 2006

The performance of immobilized fungal cells on celite beads for the production of gibberrelic acid was investigated in flasks and 7-L stirred-tank reactor. Repeated incubations of immobilized fungal cells increased cell concentrations and volumetric productivity. The maximum volumetric productivity obtained in the immobilized-cell culture was 3-fold greater than that in suspended-cell culture. The concentration of cotton seed flour (CSF), among the various nutrients supplied, most significantly influenced productivity and operational stability. Notably, insoluble components in CSF were found to be essential for production. CSF at 6 g/L with 60 g/L glucose was found to be optimal for gibberellic acid production and stable operation by preventing excessive cell growth.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1244-1249
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• 2009

Endophytic fungi are known for the production of valuable metabolites, but information on the gibberellin production capacity of this group is limited. We isolated 9 endophytic fungi from the roots of salt-stressed soybean plants and screened them on waito-c rice, in order to identify plant growth promoting fungal strains. The fungal isolate TK-2-4 gave maximum plant length (20.35 cm) promotion in comparison with wild-type Gibberella fujikuroi (19.5 cm). In a separate experiment, bioassay of TK-2-4 promoted plant length and biomass of soybean cultivar Taegwangkong. The TK-2-4 culture filtrate was analyzed for the presence of gibberellins, and it was found that all physiologically active gibberellins, especially $GA_4$ and $GA_7$, were present in higher amounts ($GA_1$, 0.11 ng/ml; $GA_3$, 2.91 ng/ml; $GA_4$, 3.21 ng/ml; and $GA_7$, 1.4 ng/ml) in conjunction with physiologically inactive $GA_9$ (0.05 ng/ml), $GA_{12}$ (0.23 ng/ ml), $GA_{15}$ (0.42 ng/ml), $GA_{19}$ (0.53 ng/ml), and $GA_{20}$ (0.06 ng/ml). The fungal isolate TK-2-4 was later identified as a new strain of Phoma herbarum, through the phylogenetic analysis of 28S rDNA sequence.

• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.560-565
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• 2009

We isolated nine endophytic fungi from the roots of salt-stressed soybean cultivar Daewonkong and screened them for growth-promoting secondary metabolites. Of all fungal isolates, P-4-3 induced maximum growth promotion of waito-c rice and soybean. Analysis of the culture filtrate of P-4-3 showed the presence of physiologically active gibberellins $GA_1$, $GA_3$, $GA_4$, and $GA_7$, along with physiologically inactive $GA_{15}$ and $GA_{24}$. The plant growth promotion and gibberellin-producing capacity of P-4-3 was much higher than wild-type Gibberella fujikuroi, which was taken as the control during the present study. The fungal isolate P-4-3 was identified as a new strain of Scolecobasidium tshawytschae through the morphological characteristics and phylogenetic analysis of 18S rDNA sequence. Gibberellins production and plant growth promoting ability of genus Scolecobasidium was reported for the first time in the present study.