以林地土壤作為天然接種物對森氏櫟苗木根部真菌菌相之影響

Effect of using native forest soil as natural inoculum on Mori Oak (Quercus morii) seedling root fungal community structure

有鑑於共生真菌對於林木生長的重要性，育苗作業上常會從森林人工林或成熟林分中收集到的各種有機物作為菌根菌的接種原。為瞭解介質中添加林地土壤是否會影響苗木根部真菌群落的組成，本研究以苗圃中添加及不添加林地土壤接種原的森氏櫟（Quercus morii）苗木為材料，以ITS序列作為標誌基因進行次世代定序，觀察根部真菌組成差異。試驗結果顯示介質中添加林地土壤影響苗木根部真菌群落的組成結構（β-多樣性），平均豐度差異顯示Scleroderma spp.及Laccaria spp.分別為兩處理中不同的優勢外生菌根菌，而以物種（OTUs）及分類群為基準的比較分析找出了造成差異的真菌，真菌群落功能分析顯示根部真菌群落主要以共生營養型的外生菌根菌組成，此外透過指標物種分析確認了在建構特定處理下菌相扮演關鍵地位的敏感性真菌。未來可視研究標的應用所得分析資料，進行潛力真菌分離培養、應用於微生物肥料試驗或作為健康苗木微生物管理的重要指標。

Given that symbiotic fungi are important to forest tree growth, various organic matter collected from forest plantations or mature forest stands are often used as inoculants for mycorrhizal fungi in seedling operations. The microbiome of the root of Quercus morii seedlings were examined by using ITS gene sequencing to understand whether fungal community in roots would be affected by adding forest soil to the medium. The results showed that addition of forest soil to the medium significantly affected the composition of fungi (β-diversity) in the roots. The difference of average abundance showed that Scleroderma spp. and Laccaria spp. were the dominant ectomycorrhizal fungi in the roots of seedlings treated with and without forest soil, respectively. Comparative analysis based on species (OTUs) and taxonomic levels revealed the fungal group that caused the difference in the composition of fungal community. The fungal community function analysis showed that the root fungal community was mainly composed of symbiotrophic ectomycorrhizal fungi. In addition, several treatment-sensitive OTUs were identified by indicator species analysis. The data and results obtained in this study can be further used for the isolation and cultivation of potential fungi and microbial fertilizer or as indicator for the microbial management for health of the tree seedling.