野生五唇兰根部内生真菌多样性研究

Endophytic fungi diversity in root of Doritis pulcherrima (Orchidaceae)

兰科植物根部的内生真菌在兰科植物的整个生活史中起着重要的作用,为了解不同生境不同类型的兰科植物内生真菌菌群的多样性,作者于2004年7月至2005年10月,以海南岛霸王岭自然保护区内的野生五唇兰(Doritis pulcherrima)作为实验材料,对不同生境、不同形态的五唇兰植株根部的内生真菌群落多样性进行了研究。从附生于石上及生于杂木林或灌丛中、叶背绿色及叶背紫红色的五唇兰植株新鲜营养根段中共分离出83株内生真菌,鉴定为19个属,其中包括培养基筛选实验中分离出的30株14属。镰刀菌属(Fusarium)(24.1%)和丝核菌属(Rhizocto-nia)(14.5%)为优势属。两种叶色的五唇兰内生真菌群落丰富度较为一致;而两种不同生境中的五唇兰内生真菌群落丰富度则表现出较大的差异:附生于灌木的五唇兰内生真菌群落Shannon多样性指数远高于附生岩石的。研究结果表明五唇兰内生真菌多样性更多地受生境的影响而不是受植株形态类型的影响。

Symbiotic relationship is maintained for endophytic fungi community throughout the life cycle of Orchidaceae plants. Endophytic fungi communities may have various biodiversities associated with different orchid species from different habitats. From July 2004 to October 2005,we studied the diversity of endophytic fungi communities in the roots of epiphytic Doritis pulcherrima with two different plant morphological variants and from two habitats in Bawangling Nature Reserve of Hainan Island. A total of 83 endophytic fungi strains were isolated from fresh root samples of the plants growing on rocks or shrubs,and with red-purple lower leaf surface or with green lower leaf surface. The isolated strains were identified into 19 genera. Fusarium （24.1%） and Rhizoctonia （14.5%） were identified as two dominant genera. Two D. pulcherrima leaf color variants have similar abundance level of endophytic fungi communities,but significant difference of the abundance level of endophytic fungi communities was presented between two habitats. The Shannon biodiversity index （H） of endophytic fungi was much higher from the D. pulcherrima growing on shrubs than growing on rocks. Our results suggested that the species diversity of endophytic fungi communities in D. pulcherrima is affected more by its different habitats than by its plant morphological variations.