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장수풍뎅이 유충의 소화기관으로부터 분리된 장내세균을 이용한 다양한 식물 균류병의 생물적 방제

Biological Control of Various Phytopathogenic Fungi Using Gut-bacteria Isolated from Digestive Organ of Allomyrina dichotoma Larva

초록/요약

This specific research was executed to select beneficial antagonists from digestive organ of Allomyrina dichotoma larva that can be put on environment friendly control against phytopathogenic fungi. The density of gut bacteria within digestive organ was 0.5ⅹ103~1.1Ⅹ107 cfu/gut. In total, 265(78, 93, 94) strains of gut bacteria were isolated from different parts such as, foregut, midgut, hindgut of digestive organ and evaluated antifungal effects against various phytopathogens in vitro. Among these isolates, 148 strains were selected as antifungal strains showing antagonistic activity against at least three of eight fungal plant pathogens, such as Botrytis cinerea, Fusarium oxysporum f. sp. radices-lycopersici, Magnaporthe grisea, Rhizoctonia solani (Rice Sheath Blight), Colletotrichum acutatum, Phytophthora capsici, Sclerotium cepivirum and R. solani (Kimchi cabbage damping-off). Under greenhouse pot trials was performed to assess the in vivo disease control efficiency of 38 strains, which showed high antifungal activity against B. cinerea, P. infestans, Plasmodiophora brassicae, C. acutatum, P. capsici through in vitro assay. As the result, DF30, DF137, DM48, DM142, DM146, DM152, DH2, DH14, DH16 and DH92 strains strongly inhibited mycelial growth of B. cinerea, P. infestans, Plasmodiophora brassicae, C. acutatum, P. capsici and as well as efficient disease control. DF30, DM142 and DH14 strains were identified as Paenibacillus polyxyxa and DF137, DH92 and DM48 strains were identified as Streptomyces sp. and DH16 strains was identified as Bacillus sp. and DM152 strains was identified as Bacillus subtilis and DM146 strains was identified as Bacillus amyloliquefaciens and DH2 strains was identified as Bacillus tequilensis based on 16S rRNA gene sequence assay. Ten bacterial strains insoluble Phosphates solubilizing activity, produced IAA, Siderophore, HCN and also retained their ability to produce β-1, 3-glucanase, protease. Also significantly enhanced all growth parameters of cilli pepper and tomato seedlings under greenhouse condition. In addition to biocontrol of the antagonistic bacteria showed the control efficacy against B. cinerea both in roots and leaves of tomato plants through reduction of pathogen propagules and developments, as well as induced systemic resistance (ISR). Moreover, the ten bacterial strains could inhibit B. cinerea in tomato leaves through ISR. This study demonstrated the possibility of selection of gut bacteria which have antagonistic effects against plant pathogens.

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목차

TABLE OF CONTENTS

ABSTRACT i
TABLE OF CONTENTS iii
LIST OF FIGURES viii
LIST OF TABLES xii
Ⅰ. 서 언 1
Ⅱ. 재료 및 방법 4
1. 길항 미생물 분리 4
1.1. 장수풍뎅이 유충 채집 및 소화기관 채취 4
1.2. 장내 미생물의 순수분리 5
1.3. In vitro 항균 활성 검정 5
2. 온실 내에서의 in vivo 스크리닝 6
2.1. 토마토 잿빛 곰팡이병 방제효과 7
2.2. 토마토 역병 방제효과 8
2.3. 배추 뿌리혹병 방제효과 9
2.4. 고추 역병 방제효과 9
2.5. 고추 탄저병 방제효과 10
3. 길항미생물의 분류 및 동정 11
3.1. 길항 미생물의 전자현미경 관찰 11
3.2. 16S rRNA gene Sequencing 11
4. 길항 미생물의 작용 메커니즘 14
4.1. 식물생장촉진호르몬(IAA)의 생성활성 조사 14
4.2. 인산 가용화(Phosphate solubilizing)활성 조사 14
4.3. Siderophore 생성능 조사 15
4.4. HCN(Hydrogen cyanide) 생성능 조사 15
4.5. β-1,3-glucanase 활성 조사 16
4.6. Protease 활성 조사 16
5. 식물생장촉진활성 효과 검정 16
5.1 식물재료 및 세균 현탁액 준비 17
5.2. 식물생장촉진활성 효과 17
6. 전신유도저항성 효과 검정 17
6.1. Inducer 처리 17
6.2. P. infestans 접종 18
6.3. RNA 분리 및 PCR 분석 18
7. 통계분석 20
Ⅲ. 결과 및 고찰 21
1. 길항 미생물 분리 21
1.1 장수풍뎅이 유충 채집 및 소화기관으로부터 장내세균 순수분리 21
1.2. in vitro 항균 활성 검정 22
2. 온실 내에서의 in vivo screening 28
2.1. 토마토 잿빛곰팡이병 방제효과 28
2.2. 토마토 역병 방제효과 30
2.3. 배추 뿌리혹병 방제효과 32
2.4. 고추 역병 방제효과 34
2.5. 고추 탄저병 방제효과 36
3. 길항 미생물 분류 및 동정 38
3.1. 길항미생물의 주사전자현미경 관찰 38
3.2. 16S rRNA gene sequencing 41
4. 길항 미생물의 작용 메커니즘 43
4.1. 식물생장촉진호르몬(IAA)의 생성활성 조사 43
4.2. 인산 가용화(Phosphate solubilizing)활성 조사 45
4.3. Sierophore 생성능 조사 47
4.4. HCN(Hydrogen cyanide) 생성능 조사 49
4.5. β-1,3-glucanase, Protease 활성 조사 49
5. 식물생장촉진활성 효과 검정 52
5.1. 토마토 식물생장촉진활성효과 검정 52
5.2. 고추 식물생장촉진활성효과 검정 55
6. 전신유도저항성 효과 검정 58
6.1. 토마토 역병 전신유도저항성에 대한 선발된 길항 미생물과 BTH 관주 처리 효과 58
6.2. ISR 유도 시 발현되는 유전자 분석 60
Ⅳ. 종 합 고 찰 62
Ⅴ. 참 고 문 헌 66
감사의 글 72

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