臺灣松科樹木的地下真菌及共生菌根之研究

Abstract

基於臺灣對於地下真菌資源調查及研究之稀缺，本研究的目的是針對一群常見的松科寄主作調查，採集野外的地下真菌子實體和菌根，透過形態學及分子生物鑑定的方式，調查臺灣的地下真菌資源，包括塊菌及其他「真、假松露」的多樣性。於2016年6月到2017年5月間，集中調查了臺灣9個地區的人工林及天然林中6種臺灣特有的松科樹種，採集所得的地下松露中發現了4個世界新種：包括雲杉松露（Tuber piceanum Wong & Li sp. nov）、溪頭松露（Tuber xitouense Wong & Li sp. nov）、臺灣腔塊菌（Hydnotrya formosanum Wong & Li sp. nov）與疣孢大團囊菌 （Elaphomyces verrucosispora Wong & Li sp. nov），以及3種臺灣新發現種：包括火冠豆松露（Endogone flammicorona Trappe & Gerdem）、緻密硬皮腹菌（Sclerogaster compactus (Tul. & C. Tul.) Sacc.）與Cenococcum geophilum Fr.之菌根，另外亦有疑似臺灣新發現種Hydnobolites cerebriformis Tul. & C. Tul.的子實體，但因缺乏成熟孢子特徵而未能完整鑑定。調查結果顯示臺灣的地下真菌資源豐富、多樣性高，值得投入更多人力與資源去研究。菌根方面雖然有依據文獻描述之地下共生菌根菌之形態搜索，但只有發現一種地下真菌菌根，大部份菌根雖然形態上很相似，但以分子技術鑑定均為地上褶菌，說明了單靠形態分辦菌根菌種類之困難與不可靠，亦顯示於環境中地上真菌與寄主共生之競爭力普遍比地下真菌強。總結各松科寄主採集到之地下真菌種類，其中與雲杉共生之菌種多樣性最高，第二為鐵杉及黃杉，第三為油杉，而冷杉及松樹則沒有發現；研究結果亦顯示於人工林之地下真菌多樣性遠高於天然林，推斷因天然林土壤中高菌根菌多樣性以致競爭太大有關。

Study of hypogeous fungi in Taiwan is scarce and insufficient, especially when comparing with epigeous mushrooms. The objective of this study is to investigate the association of hypogeous fungi with Pinaceae hosts, in both natural forest and plantation in Taiwan. Through morphological, molecular and phylogenetic analysis, sporocarp and mycorrhiza would be identified in order to study the diversity of hypogeous fungi in Taiwan. In June 2016 to May 2017, 9 locations with 6 endemic Pinaceae species were investigated. 4 new species, including Tuber piceanum Wong & Li sp. nov, Tuber xitouense Wong & Li sp. nov, Hydnotrya formosanum Wong & Li sp. nov and Elaphomyces verrucosispora Wong & Li sp. nov; and 3 Taiwan new discovery species, including Endogone flammicorona Trappe & Gerdem, Sclerogaster compactus (Tul. & C. Tul.) Sacc. and mycorrhiza of Cenococcum geophilum Fr. were found, in addition to an immature Hydnobolites cerebriformis Tul. & C. Tul. sporocarp, which possiblely be Taiwan new discovery species but unable to confirm without mature spore characteristics. Results show that hypogeous fungi in Taiwan are abundant and with high diversity, which worth input of more time and resources for further studies. Only one species of hypogeous fungi associated mycorrhiza was found in this study. Most mycorrhiza were found to be associated with epigeous mushrooms, despite their identical morphology with the hypogeous fungi associated mycorrhiza described in references. This confirm the difficulty and unreliability of identification of mycorrhizal fungi solely by mycorrhiza morphology, and review epigeous fungi comparatively more competitive in association with tree host. Comparing the hypogeous fungi diversity associating with different Pinaceae species, Picea has the highest diversity, with Tsuga and Pseudotsuga as the second and Keteleeria as the third, and no discovery for Abies and Pinus. Results also review the higher hypogeous fungi diversity in plantation than in natural forest. We believe that is caused by the high fungal diversity in soil community, resulting in fierce competition between mycorrhizal fungi in natural forest.