牛樟芝(Antrodia camphorata)為臺灣特有種真菌，僅生長在臺灣特有的牛樟樹，且是高價的藥用真菌，依其形態特徵被分類於薄孔菌屬(Antrodia)。薄孔菌屬、似薄孔菌屬(Antrodiella)、雙系孔菌屬(Diplomitoporus)三屬間的顯微特徵極為相似，目前是依照木材腐朽菌的不同及孢子的大小區分此三屬，但是這種屬間依據仍有爭議性。另外，擬層孔菌屬(Fomitopsis)與黏褶菌屬(Gloeophyllum)在木材腐朽型及顯微特徵上與牛樟芝相似。為了探討牛樟芝在多孔菌的親緣關係，本實驗利用分子生物學的方法，選取引子(primers) NS1到NS8定序18S rDNA，將多孔菌科的菌種作18S rDNA基因序列之合成、純化及定序之後，進行譜系分析，推算其親緣關係。由親緣關係樹圖的結果得知，牛樟芝與似薄孔菌屬較近而與黏褶菌屬較遠。另外，由親緣樹圖來看，上述各屬間並無交錯的現象，表示各屬間的依據是合理的，但是牛樟芝在親緣樹圖中並不屬於薄孔菌屬，其分類地位則有待更進一步的研究。 "Niu-chang-chih" is endemic to Taiwan and is known only restricted to a Taiwan endemic tree species: Cinnamomum kanehirai Hay.The species is famous and highly valued in Taiwan as a medicine. The fruit body morphology of this species corresponds with Antrodia P. Karst fairly well. As with similar micromorphologic characteristics among Antrodia, Antrodiella and Diplomitoporus, the decay characteristics and the type of the spores were the main emphasis for their morphological classification. But it is arguable for their delimitation. And what is more, Fomitopsis and Gloeophyllum also have similar morphology with "niu-chang-chih". To discuss phylogenetic relationships of "niu-chang-chih", DNAs representing the complete sequence of 18S rDNA of polypores were amplified by polymerase chain reaction (PCR). The complete nucleotide sequences of the 18S rDNA were obtained and analyzed to study the relationship of "niu-chang-chih" among some other related genera of the polyporaceae, The phylogenetic tree of the polypores were defined and based on the maximum parsimony analysis.In this study,we find the "Niu-chang-chih" is far distance relationship with Gloeophyllum, and closer to Antrodiella. Moreover, the results also support the classification of the genera except "niu-chang-chih". More researches need to be done in order to determine its classification.
