초록 ▼

□ 과제명 : 유용미생물을 활용한 유기농 인삼의 뿌리썩음병 억제 기술개발
▶ 연구목적 : 인삼뿌리썩음병 억제 미생물의 개발 및 이를 이용한 미생물 퇴비 개발
○ 유기농 인삼재배를 위한 토착미생물자원 확보 – 토양병방제용 길항균개발
○ 고품질 인삼재배를 위한 화학비료 대체용 유기질비료 생산기술개발
○ 인삼 뿌리썩음병 방제를 위한 고활성 미생물 선발 및 특성검정
○ 분자생물학적 방법을 이용한 인삼 재배지 뿌리썩음병 밀도 확인
○ 선발된 기능성 미생물의 병원균 억제기작 구명
▶ 주요연구내용
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□ 과제명 : 유용미생물을 활용한 유기농 인삼의 뿌리썩음병 억제 기술개발
▶ 연구목적 : 인삼뿌리썩음병 억제 미생물의 개발 및 이를 이용한 미생물 퇴비 개발
○ 유기농 인삼재배를 위한 토착미생물자원 확보 – 토양병방제용 길항균개발
○ 고품질 인삼재배를 위한 화학비료 대체용 유기질비료 생산기술개발
○ 인삼 뿌리썩음병 방제를 위한 고활성 미생물 선발 및 특성검정
○ 분자생물학적 방법을 이용한 인삼 재배지 뿌리썩음병 밀도 확인
○ 선발된 기능성 미생물의 병원균 억제기작 구명
▶ 주요연구내용
○ 1세부과제명 : 인삼뿌리병 방제를 위한 기능성 미생물 퇴비개발
- 인삼뿌리썩음병에 관여하는 5종의 토양병원균에 길항력을 갖는 방선균 BK185를 인공배양하여 배지 1㎖ 당 10^7∼8 포자수를 수확, 생산 경제성 높았음.
- 축분을 발효시킨 후 방선균 BK185을 첨가 한 퇴비는 토양병원균을 효과적으로 방제하였다. 병원균을 인공접종한 토양에서 미생물퇴비는 병 방제가가 90% 이상으로 높았으며, 인삼밭에 살포한 결과 관행으로 재배하는 농가 보다 수량이 증가 하였다.
- 유기인삼재배를 위해 개발한 미생물퇴비를 첨가한 상토는 재배기간 중 추비가 필요하지 않았으며, 잘록병과 같은 토양병도 발생하지 않아 무비료, 무농약 묘삼 생산이 가능하였다.
- 생산된 묘삼은 평균 무게 0.8g, 근장 16.2㎝로 갑삼 비율이 40% 이상이었다.
○ 1협동과제명 : 유기농 인삼의 뿌리 썩음병 억제 미생물의 선발 및 기능 구명
- 인삼밭 토양, 논토양 및 식품으로부터 분리한 1,800여 균주의 탐색을 통해 인삼 뿌리썩음병에 강한 억제 활성을 갖는 유용 미생물 선발 : 세균 2균주(GR4-5, GH1-13)와 방선균 1균주(BK185) : 3균주는 특허출원함
- 뿌리썩음병 발병 토양에서 유용 균주(BK185)에 의한 병원균 밀도가 감소함을 검정
- 유용미생물(GR4-5) 처리 후 토양에 처리한 후 생존능 확인함(실내 14일 및 실외 7일).
- 선발균주의 병원균 억제관련 물질 확인 : 방선균 BK185균주는 항진균 활성을 갖는 geldanamycin을 생성함을 확인하였으며, Bacillus GR4-5균주는 항진균 활성을 갖는 iturinC를 생성을 확인함.
- 유전자 분석을 통해 PKS, NRPS 유전자를 확인하였으며, 유전체 분석을 통해 생합성 유전자 cluster의 존재를 확인함.

Abstract ▼

Ginseng(Panax ginseng C.A. Meyer) cultivate for 4∼6 years to harvest root under a solar shuttered bed in korea. The ginseng garden’s shade circumstance and long term requirement to harvest, ginseng plant sensitive to the phytopathogens which attack phylloplane or rhizosplane. To practice organic gin

Ginseng(Panax ginseng C.A. Meyer) cultivate for 4∼6 years to harvest root under a solar shuttered bed in korea. The ginseng garden’s shade circumstance and long term requirement to harvest, ginseng plant sensitive to the phytopathogens which attack phylloplane or rhizosplane. To practice organic ginseng cultivation, the most important field managing technique which needed for successful ginseng cultivation is to control root-rot disease effectively and to prepare a good organic fertilizer for a long term sufficient nutrient supply. Among the ginseng pathogens, ginseng root-rot caused by soil-borne pathogens was the most prevalent problem in the ginseng garden. To establish a strategy to control the ginseng root-rot with envionment friendly agent, we isolated four promising candidates as the bicontrol agents among the 1,800 bacterial strains which collected from ginseng root and traditional fermented foods. In dual culture test.
They inhibited the mycelial growth of Cylindrocarpon destructans, Rhizoctonia soani , Sclerotinia nivalis, S. sclerotiorum, Botrytis cinere on PDA. Based on real-time PCR methods and biochemical characteristics, they were identified as Bacillus amyloliquefaciens GR4-5, B. methylotrophicus GH1-13, Pseudomonas fluorecens, Streptomyces geldanamycininus BK185 each other. By analysis of bioactive compounds produced by antagonistic bacteria., strain GR4-5, strain GH1-13 and strain BK185 showed strong antagonistic activity against root-rot disease. As an antifungal metabolite, strain BK185 produced geldanamycin which had antifungal activity and strain GR4-5 produced iturin C. By PCR analysis, Strain BK185 and Strain GR4-5 had polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) genes in their genomes. All of the these results suggest that the strains have excellent potential as a good biocontrol agents for controlling ginseng root-rot.
To test the soil borne disease control ability of antagonistic strains in soil, the population fluctuation of introduced antagonistic strains in the solar shuttered bed soil and ginseng rhizosphere was studied with PCR. Bacterial community analysis of ginseng rhizosphere by pyrosequencing showed P . fluorescens were more abundant in the rhizosphere than bulk soil and it can be used as a powerful biocontrol agent against ginseng root-rot disease. Measurement of survivability of the beneficial bacteria showed that strain GR4-5 can survive in bulk soil for 10 days, indicating that the strain should be inoculated by irrigation every 2 weeks for an effective application against plant disease.
To increase the biocontrol efficacy of composted livestock manure against soil-borne disease and to supply enough nutrient required to grow high quality ginseng, we prepared a antagonistic microorganism added organic fertilizer(AMOF). To produce AMOF, we developed techniques for the antagonist mass cultivation on solid medium, the alive microorganism containing formulator manufacureing protocole and the manure composting procedure which maximize the viability and colonization ability of antagonistic isolate in soil. The AMOF prepared by inoculating strain BK185 to organic fertilizer. The organic fertilizer produced after composting of cow dung and soybean debris mixture. Composting procedure needed for 90days and three times turning. The organic fertilizer produced after composting, pH value decreased to 6.9 and the content of total nitrogen was 1.98%. The strain BK185 which used to AMOF manufacture, grew well to spores on mineral nutrient added potato extract agar in 15 days and the number of spores per ㎖ was 10 bilion. The organic fertilizer stimulated the spore germination rate of strain BK185 equal to 1% sucrose solution. The AMOF effectively controlled from the soil borne disease and promoted the healthy ginseng growth, inhibited the mycelium growth of C. destructans. Bioassays with strain BK185 added compost-amended and non-amended soil, which was previously developed the serious root rot disease and the survived 6 year old ginseng number decreased to less than 40%, were practiced to evaluate the disease incidence decreasing effect on ginseng root rot. The percentage of rotted root numbers in C. destructans inoculated soil was 46.7% but the disease incidence decreased to 4.2% after AMOF amendment.
To shorten and increase seed germination rate, the seed was collected from the red, ripe berries by mashing the berries and washing the debris off. The seeds were then mixed with coarse sand at a ratio of two parts sand to one part seed. The seed/sand mixture is put in 300ℓ plastic vessel and placed in cool stratified place. The stratified place maintained for 4 months with sufficient mineral water pouring for leaching and prohibiting harmful microorganism colonization. This process helps seed coat cracking while the embryo develops and grows. Stratified seed stored in –2℃ refrigerator during winter(September through March) and planted in early spring. The stratified ginseng seed germinated more than 80% and rotted seed was less than 3%. Stratified ginseng seeds plant in self soil nursery(virgin soil nursery) or yang jik nursery(mixture saprolio 5 parts and fertilizer 1 parts by volume) and grow for 1 year to harvest rootlet. The digged rootlet transplant into the ginseng garden and cultivate for 3∼5years in korea. During the ginseng seedling cultivation in above two nursery, many soil-borne pathgens infest and injury on ginseng seedling. To overcome the problems which developed in soil nursery, we prepared the artificial nursery medium(ANM) which contains peat moss 10 parts, perlite 10 parts and AMOF 2 parts by volume. The stratified seed planted 298 seeds in each nursery box(49w X 33l X 23h, ㎝) filled up with ANM by hand made seed machine in spring, and cover the seeds with 2 ㎝ of topsoil. After planting, carefully pressed to firm the nursery medium around the seeds. The ANM had beneficial aspects, sprouting rate enhanced about 6% more than yangjik nursery, need not the additional fertilizer supply and fungicide spray. The ANM needed only regular water irrigation to maintain appropriate moisture. The average weight of rootlet was 0.87g per root and root length was 11.7㎝, and the percentage of high quality seedling number was 60%. The organic ginseng seedling growing was practicable with the ANM, it need not chemical fungicide spray or chemical fertilizer supply.