• Asian-Australasian Journal of Animal Sciences
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• 제9권5호
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• pp.519-524
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• 1996

An investigation was carried out to study the microbial colonization and degradation of five crop residues, viz., sago waste, rice straw, oil palm trunk shavings, untreated palm press fibre and palm press fibre teated with 3% ammonium hydroxide in the rumen of goats. Colonisation by rumen bacteria and fungi was already established on all the five crop residues 8 h after incubation. However, the extent of colonization varied among the crop residues. Microbial colonization was poor on palm press fibre (treated and untreated) but more extensive on sago waste, oil palm trunk shavings and rice straw. By 24 h, most of the soft-walled tissues in sago waste, rice straw and oil palm trunk shavings were degraded leaving the thick-walled tissues extensively colonized by bacteria and fungi. Degradation on palm press fibre was still limited. At 48 h, the thick-walled tissues of sago waste, oil palm trunk shavings and rice straw showed various degrees of degradation - from small erosion zones to large digested areas. Bacterial growth was similar to that at 24 h but fungal growth was less. On palm press fibre, microbial colonization was more extensive than at 24 h but degradation of the fibres was still limited. Degradation of all the five crop residues at 72 h was somewhat similar to that at 48 h. Overall, microbial colonization and degradation were the most extensive on sago waste, followed by rice straw and oil palm trunk shavings, and the least on palm press fibre (treated and untreated). Dry matter loss of the five crop residues at the various incubation periods also showed the same order of degradation.

• 식물병연구
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• 제15권2호
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• pp.101-105
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• 2009

Serratia plymuthica A21-4는 양파(Allitum fistulosum L.) 근권에서 분리된 고추 역병 생물적 방제 미생물이다. 토양 환경이 S. plymuthica A2l-4 근권정착에 미치는 영향을 알아본 결과 사질이 많이 포함되어 공극이 많은토양에 3% 중량(w/w)의 부숙된 옥수수 줄기를 첨가하고 토양 수분함양이 40% 정도, 토양온도가 $20^{\circ}C$, 토양 pH가 중성이거나 약산성 토양이 S. plymuthica A2l-4의 근권정착에 유리하였다. 그리고 토착미생물이 있는 것이 살균한 토양에서 보다 S. plymuthica A21-4의 근권정착에 유리하였다.

• 대한수의학회지
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• 제33권3호
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• pp.471-478
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• 1993

Culicoides arakawae is a kind of the main blood sucking insects of domestic fowls and serves as a vector of Leukocytozoom caulleryi, the causative protozoon of chicken leukocytozoonosis. In this study, the complete life history of C arakawae was cycled by laboratory colonization. Adult midges were collected from various poultry farm by light trap. The laboratory colonization was performed under the conditions of constant temperature of $25{\pm}1^{\circ}C$ and relative humidity of 80% or above. The hatched larvae were cultured in larval medium consisted of rice field mud and activated charcoal powder. The surface of medium was continuously flowed with biologically conditioned water. The fine powder meal composed of pellet feed for mice and equal mount of yeast was supplied for feeding larvae at every 72 hours. The life cycle completed at $25^{\circ}C$ in 35~35 days ; the period of preoviposition, egg. larval and pupal stage was 2~3, 3~4, 28~30 and 3 days, respectively. The measurements of the eggs, the lst instar larvae, the 4th instar larvae and pupae was $36.28{\mu}m{\pm}1.95$, $13.58{\mu}m{\pm}0.72$, $4000{\mu}m{\pm}1.47$ and $219.95{\mu}m{\pm}6.25$ in $mean{\pm}S.D.$, respectively. In order to confirm experimental colonization of C arakawae in laboratory, the colonized adult midges were allowed to suck blood from chicken infected with L caulleryi. The oocysts and sporozoites could be identified in midguts and salivary grands of engorged midges at 72 hours after blood sucking.

• The Plant Pathology Journal
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• 제39권1호
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• pp.123-135
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• 2023

Previously, Pseudomonas plecoglossicida YJR13 and Pseudomonas putida YJR92 from a sequential screening procedure were proven to effectively control Phytophthora blight caused by Phytophthora capsici. In this study, we further investigated the anti-oomycete activities of these strains against mycelial growth, zoospore germination, and germ tube elongation of P. capsici. We also investigated root colonization ability of the bacterial strains in square dishes, including cell motility (swimming and swarming motilities) and biofilm formation. Both strains significantly inhibited mycelial growth in liquid and solid V8 juice media and M9 minimal media, zoospore germination, and germ tube elongation compared with Bacillus vallismortis EXTN-1 (positive biocontrol strain), Sphingomonas aquatilis KU408 (negative biocontrol strain), and MgSO₄ solution (untreated control). In diluted (nutrient-deficient) V₈ juice broth, the tested strain populations were maintained at >10⁸ cells/ml, simultaneously providing mycelial inhibitory activity. Additionally, these strains colonized pepper roots at a 10⁶ cells/ml concentration for 7 days. The root colonization of the strains was supported by strong swimming and swarming activities, biofilm formation, and chemotactic activity towards exudate components (amino acids, organic acids, and sugars) of pepper roots. Collectively, these results suggest that strains YJR13 and YJR92 can effectively suppress Phytophthora blight of pepper through direct anti-oomycete activities against mycelial growth, zoospore germination and germ tube elongation. Bacterial colonization of pepper roots may be mediated by cell motility and biofilm formation together with chemotaxis to root exudates.

• 한국환경농학회지
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• 제17권2호
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• pp.174-181
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• 1998

유기농법으로 관리하는 감귤원과 일반관리를 하는 감귤원 각 2곳씩 총 4곳에서 감귤원 토양내 arbuscular mycorrhizae(AM)균 포자를 동정하고 포자밀도와 은주밀감(탱자대목)과 잡초 뿌리의 AM균 감염율 변화를 96년 10월부터 97년 10월까지 2개월에 간격으로 조사하였다. AM균 포자는 Glomus속 3종(G. deserticola, G. vesiculiferum, G. rubiforme )과 Acaulospora속 1종 (Acaulospora sp.)이 동정되었다. AM균 포자밀도는 토양 100g당 10,000${\sim}$40,000개의 범위로 조사되었는데, 유기농 감귤원에서 훨씬 높았다. 모든 감귤원에서 12월에 포자밀도가 가장 낮았으나 가장 높은 시기는 유기농 감귤원에서는 4월이었지만 일반관리 감귤원에서는 2월 또는 4월이었다. 감귤뿌리의 AM균 감염율은 유기농 감귤원에서 연평균 27% 이상이었으며 4월과 10월에 가장 높고 8월에 가장 낮은 반면 일반관리 감귤원에서는 연평균 15% 미만이었으며 2월에 최고치를 보였고 최저치를 보이는 시기는 감귤원과 해에 따라 달랐다. 전체적으로 포자밀도와 AM감염율은 유기농법으로 관리하는 감귤원에서 높은 경향이 있었다. AM 감염율의 연중 변화는 sigmoid 곡선으로 나타나는데 겨울철에는 낮은 감염을 보이고 이른 봄부터 서서히 증가하여 4-5월경 최대 감염율을 보였으며 숙주식물의 영양생장이 끝나면서 감염율도 감소하였다. 토양중의 포자밀도 변화도 AM 감염율의 변화와 동일한 경향이었다. 토양중 유효인산과 유기물의 함량은 AM 감염율에 영향을 미치지 않았으며 토양 요인보다 식물 기후학적 요인의 영향이 더욱 중요하게 작용하는 것으로 판단된다. 감귤원에서 발생하는 잡초 중에서 콩과의 자운영과 쇠비름과의 쇠비름이 높은 AM 감염을 보였는데 이들은 AM균의 접종재료나 중식용 숙주식물로써의 이용 가치가 높을 것이다.

• Mycobiology
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• 제36권2호
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• pp.81-87
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• 2008

The optimal conditions for mycelial growth of Phellinus linteus ATCC 26710 were determined to be a log length of 20 cm, temperature of $30^{\circ}C$ and pH of 6.0. Mycelial growth was excellent on the mushroom complete medium, and was optimal when sucrose, man nose and glucose were supplied as carbon sources. Potassium nitrate and sodium nitrate as nitrogen sources supported good mycelial growth. To evaluate P. linteus mycelial colonization on logs, sterilized short log inoculation, drilling inoculation and log-end sandwich inoculation techniques were used. Only sterilized short log inoculation produced good mycelial colonization. Initial mycelial growth and full mycelial colonization were best on 20 cm logs having 42% moisture content. The initial mycelial growth of P. linteus was accelerated over 12hr of sterilization. Basidiocarp formation was optimal using a burying method of logs after $5{\sim}6$ months, and fruiting body formation was superior in cultivation house conditions of $31{\sim}35^{\circ}C$ and in excess of 96% relative humidity.

• The Korean Journal of Ecology
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• 제8권3호
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• pp.141-146
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• 1985

Colonization ability was studied with Lemna paucicostata and Spirodela polyrhiza. Colonization ability of each species was defind as its ability to; (1) tolerate to desiccation, (2) multiplicate and spread in the new habitat, (3) inhibit the other species competitively. Lemna paucicostata was inferior to Spirodela polyrhiza in ability (1), but superior to Spirodela polyrhiza in abilities (2) and (3). Whenever lemna paucicostata and Spirodela polyrhiza are colonized recently, only these three abilities can not explain which species is better colonist. Even short unsuitable periods would eliminate a species, with time lag occurring before recolonization. This would result in a discontinuous of the species concerned.

• Mycobiology
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• 제40권3호
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• pp.168-172
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• 2012

In this study, the effect of soil ameliorators on ectomycorrhizal (ECM) fungal communities in coal mine spoils was investigated. Organic fertilizers and slaked lime were applied as soil ameliorators in 3 abandoned coal mine spoils. One year after the initial treatment, roots of Pinus densiflora seedlings were collected and the number of ECM species, colonization rate, and species diversity were assessed. The results showed that the soil ameliorators significantly increased ECM colonization on the roots of P. densiflora. The results suggest that soil ameliorators can have a positive effect on ECM fungi in terms of growth of host plants and show the potential use of soil ameliorator treatment for revegetation with ECM-colonized pine seedlings in the coal mine spoils.

• The Plant Pathology Journal
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• 제28권2호
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• pp.202-206
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• 2012

Root colonization by the rhizobacterium Pseudomonas chlororaphis O6 in Arabidopsis thaliana Col-0 plants resulted in induced tolerance to drought and salinity caused by halide salt-generated ionic stress but not by osmotic stress caused by sorbitol. Stomatal apertures decreased following root colonization by P. chlororaphis O6 in both wild-type and ABA-insensitive Arabidopsis mutant plants. These results suggest that an ABA-independent stomatal closure mechanism in the guard cells of P. chlororaphis O6-colonized plants could be a key phenotype for induced systemic tolerance to drought and salt stress.

• Mycobiology
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• 제28권3호
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• pp.115-118
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• 2000

To determine the degree of variability among the host plant species in their abilities to become colonized by arbuscular mycorrhizal fungi (AMF), the inoculum for AMF was collected from the various sites in Korea and was inoculated to the three horticultural plants; Tagetes patula, Torenia fournieri, and Salvia splendens. After 4-month growth under greenhouse, mycorrhizal root colonization rates and spore density were measured. The roots of T. patula showed higher colonization rate than both plants of T. fournieri and Salvia splendens. The mycorrhizal root colonization was influenced by both of the AM fungal inoculum and the host species or their interactions. The combination of the host and fungal species was suggested to be important for the application of AMF to horticultural crops.