循環農業：農業有機廢棄物生物處理再利用【土環系沈佛亭副教授】
論文篇名 英文：Exploration of root-associated bacteria from the medicinal plant Platycodon grandiflorum
中文：藥用植物桔梗根系細菌之開發
期刊名稱 Microbes and Environments
發表年份,卷數,起迄頁數 2019 (in press) (Published online October 12, 2019)
作者 Huang, Cong-Min; Chen, Wen-Ching; Lin, Shih-Han; Wang, Yu-Ning; Shen, Fo-Ting* (沈佛亭)
DOI 10.1264/jsme2.ME19030
中文摘要 本研究旨在分離藥用植物桔梗之根系細菌，並開發可促進桔梗生長之有益微生物。研究中利用多種培養基分離根圈與根內細菌，再利用16S rDNA序列分析得知各分離株之分類地位。自上述分離株中挑選較無生物安全疑慮之數株內生菌，進一步探討其促進作物生長與適應棲地之特性，最後再以接種試驗探討內生菌對桔梗幼苗和成熟植株生長之影響。本研究自桔梗根系分離之細菌可歸類至17菌屬(至少30菌種)，其中大部分菌種過去皆未曾被報導與桔梗相關，特別是為數眾多而不可被忽略的變形菌門類。雖然上述試驗之內生菌皆具有固氮或溶磷與IAA生成能力，經接種至植體後顯示其具有促進或抑制植物生長之效應。本研究發現1株在分類上具新穎性之Rhizobium菌株，是與此非豆科類藥用植物相容性最佳的菌種。此外本研究亦提出在開發植物生長促進之根圈細菌時，除了過去已知與植物生長促進之相關特性外，菌株水解植物體組成分之特性亦應列入考慮並深入探討其對植物生長之影響。
英文摘要 The present study was performed to investigate root-associated bacteria from Platycodon grandiflorum, a medicinal plant commonly grown in East Asia. Isolates were obtained from the rhizosphere or root interior with various culture media, and phylogenetic analyses were performed based on their 16S rDNA sequences. In consideration of practical applications, traits related to plant growth promotion and niche adaptation were assessed in several endophytic strains with fewer biosafety concerns. The effects of a bacterial inoculation on seedling and mature plant growth were evaluated. Seventeen genera that encompassed more than 30 bacterial lineages were successfully retrieved from the roots, the majority of which have not been reported as P. grandiflorum-associated bacteria, particularly for non-negligible Proteobacteria. Although nitrogen-fixing or phosphate solubilizing and indole acetic acid-producing activities were recorded in all of the strains selected, these strains were beneficial or detrimental to plant growth as evidenced by their influence on the length of seedlings and biomass of mature plants. Among the 4 endophytic Rhizobium species tested in the present study, the potentially novel Rhizobium sp. BF-E16, which was more compatible with the non-leguminous medicinal plant P. grandiflorum, was identified. Other than plant growth-promoting traits, characteristics such as plant constituent-hydrolyzing activities need to be taken into consideration and their roles clarified when investigating plant growth-promoting rhizobacteria.