兔眼藍莓與天然芬蘭泥炭苔中，共生真菌專一性之探討

Host-fungus specificity between rabbiteye blueberries and symbiotic fungi in nature Finnish peat mosses

"藍莓(Vaccinium spp.)為好酸性之杜鵑花科(Ericaceae)越橘屬植物，臺灣栽培藍莓時，常以泥炭苔調節介質酸性及有機質含量。泥炭中普遍存在可侵染杜鵑花科植物之杜鵑花類菌根菌(ericoid mycorrhizal fungi, EMF)及暗色隔膜內生菌(dark septate endophytes, DSE)，本研究觀測以芬蘭天然酸性泥炭苔種植之兔眼藍莓(V. virgatum)，根部共生真菌型態及侵染率，探討泥炭苔可能之共生真菌種類，及其對不同品種兔眼藍莓之侵染能力與專一性之差異。本研究共調查定植後1-2年生兔眼藍莓10品種，所有品種根部均觀測到EMF及DSE之共生現象，接種源應為芬蘭泥炭苔，依侵染型態及芬蘭泥炭中共生真菌種類之記錄，推測EMF種類可能為: Rhizoscyphus ericae、Oidiodendron maius或Meliniomyces variabilis，DSE可能為Phialocephala fortinii。所有受試品種之EMF侵染率皆較DSE高。EMF侵染頻率介於22.0%至62.0%，侵染強度介於1.5%至5.2%。DSE侵染頻率介於2.7%至17.3%，侵染強度介於0.1%至2.4%。合計總侵染頻率介於30.7%至68.0%，總侵染強度介於2.7%至7.4%。不同品種間，EMF對‘Austin’之侵染率最低，對‘Aliceblue’、‘Beckyblue’、‘Climax’及‘NTU-104’較高。DSE對‘Beckyblue’之侵染率最低，對‘Bonita’、‘Climax’、‘NTU-104’及‘Premier’較高。本研究結果顯示泥炭中之EMF及DSE可與兔眼藍莓根系共生，但侵染力及專一性偏低，在正常肥培管理下是否具有促進植株生長之效益，有待進一步驗證。"

"Blueberries (Vaccinium spp.) are acidiphilic ericaceous plants (Ericaceae) that thrive in acid soil. Peat mosses are often used for blueberry cultivation in Taiwan to regulate substrate pH and organic matter content. Previous studies indicated that symbolic fungi, e.g., ericoid mycorrhizal fungi (EMF) and dark septate endophytes (DSE), are common in peatlands and are capable of colonizing blueberry hair roots. In this study, symbiotic fungal morphology and colonization rate in rabbiteye blueberry (V. virgatum) hair roots were observed to identify possible fungal species in the peatmoss and their colonization rates in different specificity to rabbiteye blueberries cultivars. Colonization of both EMF and DSE were observed in hair roots of all 10 tested rabbiteye cultivars grown in substrate containing nature Finnish peatmoss. Base on the fungal morphology and species records in Finnish peatmoss, the EMF might be Rhizoscyphus ericae, Oidiodendron maius or Meliniomyces variabilis. The DSE might be Phialocephala fortinii. Colonization rates of EMF were higher than those of DSE in all cultivars. The colonization frequencies of EMF were in the range of 22.0% to 62.0% and the colonization intensities between 1.5% and 5.2%. The colonization frequencies of DSE were in the range of 2.7% to 17.3% and the colonization intensities between 0.1% and 2.4%. Total fungal colonization frequencies were in the range of 30.7% to 68.0% and total colonization intensities between 2.7% and 7.4%. The colonization rate of EMF was lowest in‘Austin’and highest in‘Aliceblue’,‘Beckyblue’,‘Climax’, and‘NTU-104’. The colonization rate of DSE was lowest in‘Beckyblue’and highest in‘Bonita’,‘Climax’,‘NTU-104’, and‘Premier’. The result indicated that symbiotic fungi in nature Finnish peatmoss were capable of colonizing hair roots of rabbiteye blueberries, but the specificity was low. Whether such low level of colonization is beneficial to blueberry plants in commercial cultivation environment warrants further evaluations."