왕벚나무에서 분리한 내생균류의 다양성 및 목재부후균에 대한 생장억제효과 = Biodiversity of Endophytic Fungi Isolated from Prunus yedoensis and their Effects on Growth Inhibition against Wood Decay Fungi

다국어 초록 (Multilingual Abstract)

Wood decay fungi, including Trametes versicolor, Ganoderma gibbosum, and Vanderbylia fraxinea have been a major threat to Prunus yedoensis, which is one of the most planted street trees in the southern regions of South Korea. Endophytic fungi, non-pathogenic fungi mainly living in plant tissues, were isolated from decayed and un-decayed Prunus yedoensis trees to investigate their biodiversity and antifungal efficacy against the wood decay fungi. A total of 257 fungal isolates were recovered from the inner lower trunk samples of 10 Prunus yedoensis trees and identified as belonging to 49 species. Parapyrenochaeta maryellenpeartiae(31.9%), Paraconiothyrium brasiliense(9.3%), and Paraboeremia putaminum(8.95%) were the most dominant species of endophytic fungi in Prunus yedoensis trees. In the decayed Prunus yedoensis, 184 fungal isolates were identified into 31 species, while 73 fungal isolates with 33 species were recovered from the un-decayed trees. Shannon-Wiener index, Species Evenness index, and Dominance index for the isolated endophytic fungi were not significantly different between decayed and un-decayed Prunus yedoensis trees. Eleven endophytic fungal species showed antifungal activity in the primary and secondary screening for the endophytic fungi isolated inhibiting mycelial growth of wood decay fungi. Among them, BEN48(Fusarium acuminatum), BEN36(Paraconiothyrium sp.), and BEN79(Candolleomyces candolleanus) had relatively higher antifungal activities with the inhibition rates from 26.8 to 36.9% against Trametes versicolor. BEN48(Fusarium acuminatum) and BEN97(Nigrograna acericola) had the highest inhibition rates with 44.9% followed by BEN36(Paraconiothyrium sp.) with 37.8%, BEN37(Paraboeremia putaminum) with 31.3%, BEN7(Paraconiothyrium brasiliense) with 29.6% against Ganoderma gibbosum. BEN48(Fusarium acuminatum) had the highest inhibition rate with 62.6% followed by BEN7(Paraconiothyrium brasiliense) with 59.1%, BEN36(Paraconiothyrium sp.) with 58.5%, BEN37(Paraboeremia putaminum) with 50.7%, BEN97(Nigrograna acericola) with 44.6% against Vanderbylia fraxinea. The most effective endophytic fungal species including BEN7(Paraconiothyrium brasiliense), BEN36(Paraconiothyrium sp.), BEN48(Fusarium acuminatum), and BEN97(Nigrograna acericola) were selected for culture filtrate tests. The culture filtrate from BEN48(Fusarium acuminatum) showed significantly higher mycelial growth inhibition rates (64.5~96.7%) than others on PDA medium where the three wood decay fungi were grown, followed by BEN7(Paraconiothyrium brasiliense) with 24.1~63.1%. Mycelial growth inhibition rates of BEN48(Fusarium acuminatum) were not significantly different between heated and un-heated media, while those of BEN7(Paraconiothyrium brasiliense) were significantly different, showing higher mycelial growth inhibition rates on the un-heated media, which means that some effective secondary metabolites in the culture filtrates of BEN48(Fusarium acuminatum) were stable in the heated condition but those of BEN7(Paraconiothyrium brasiliense) were chemically changed and their antifungal activities reduced after autoclaving. For the development of biocontrol agents against wood decay fungi, solvent fractionation of culture filtrates for the selected endophytic fungi, BEN48(Fusarium acuminatum) and BEN7(Paraconiothyrium brasiliense) and their antifungal activity tests as well as identification of bioactive substances should be further studied.

목차 (Table of Contents)

• Ⅰ. 서론 1
• Ⅱ. 연구사 4
• Ⅲ. 재료 및 방법 7
• 1. 시료 수집 7
• 1) 왕벚나무 내부 부후도 측정 및 목재부후균 자실체 수집 7
• 2) 내부 목질부 시료 수집 9
• 2. 내생균 분리 및 순수배양 11
• 1) 목재부후균 자실체의 균 분리 11
• 2) 목질부 조직에서 내생균 분리 12
• 3. 분리된 내생균의 동정 13
• 4. 분리된 내생균의 다양성 및 군집분석 15
• 5. 목재부후균 생장 억제 검정 16
• 6. 내생균의 배양여액을 이용한 항진균 활성 평가 18
• 7. 통계분석 20
• Ⅳ. 결과 및 고찰 21
• 1. 왕벚나무 주요 목재부후균 균주 확보 21
• 2. 왕벚나무 내생균의 다양성 23
• 1) 분리된 내생균의 전체 다양성 23
• 2) 부후목과 건전목의 내생균 다양성 비교 38
• 3) 군집비교 42
• 3. 목재부후균의 균사생장 억제검정 43
• 1) 1차 스크리닝(Primary screening) 43
• 2) 2차 스크리닝(Secondary screening) 46
• 4. 배양여액을 이용한 목재부후균의 항진균 활성 평가 55
• 1) 배양여액 첨가 농도별 항진균 활성 평가 55
• 2) 가열 유무에 따른 목재부후균의 항진균 활성 평가 64
• Ⅴ. 결론 66
• Ⅵ. 참고문헌 69