四川黄龙沟优势兰科植物菌根真菌多样性及其季节变化  

The variations of mycorrhizal fungi diversity among different growing periods of the dominant orchids from two habitats in the Huanglong valley,Sichuan

作　　者：侯天文[1] 金辉[2] 刘红霞[1] 安德军[3] 罗毅波[2] 

机构地区：[1]北京林业大学森林培育和保护国家重点实验室,北京100083 [2]中国科学院植物研究所系统与进化植物学重点实验室,北京100093 [3]四川省黄龙国家级风景名胜区管理局,黄龙624000

出　　处：《生态学报》2010年第13期3424-3432,共9页Acta Ecologica Sinica

基　　金：国家科技支撑计划课题资助项目(2008BAC39B05);国家科技支撑计划课题资助项目(2006BAD07B02)

摘　　要：在自然条件下,兰科菌根真菌对兰花的种子萌发和植株生长都是必不可少的。为了解高原兰科植物菌根真菌的多样性状况及其季节性变化规律,选取了四川黄龙沟的两种生境中生长的8种优势兰科植物,分别于植株的萌芽期(4月份)、生长期(7月份)和果期(9月份)采集营养根进行菌根真菌的多样性研究。其中,黄花杓兰(Cypripedium flavum)、少花鹤顶兰(Phaiusdelavayi)、二叶匍茎兰(Galearis diantha)和广布小蝶兰(Ponerorchis chusua)分布在开阔生境;筒距兰(Tipularia szechuanica)、小花舌唇兰(Platanthera minutiflora)、珊瑚兰(Corallorhiza trifida)和尖唇鸟巢兰(Neottia acuminate)则分布在密林生境。通过对分离所得的50个菌株进行形态观察和ITS序列测定相结合的鉴定,共获得菌根真菌41种。对担子菌和子囊菌分别进行的系统发育树构建结果显示,子囊菌为优势种类(35种),以柔膜菌目(Helotiales)、炭角菌目(Xylariales)和肉座菌目(Hypocreales)内的种类为主,担子菌则以胶膜菌(Tulasnellaceaesp.)为主。在8种兰科植物中,二叶匐茎兰表现出极高的专一性,其菌根真菌均属于Hypocrea。其余兰科植物的菌根真菌分别属于不同的科,专一性相对较低。物种丰富度和Simpson多样性指数分析结果表明,密林生境的兰科植物的菌根真菌多样性在各生长季节基本高于开阔生境。此外,两种生境的优势兰科植物的菌根真菌物种多样性随生长季节转变所呈现的变化规律是相似的:萌发期和生长期的多样性均较高,峰值出现在生长期,到果期时则大幅下降。这与高原兰科植物的生长特性及营养供求规律基本相符。All orchids have an obligate relationship with mycorrhizal symbionts during seed germination under field conditions,and in many species,the dependency on fungi as a carbohydrate source is prolonged into adulthood.Diversity of orchid mycorrhiza is defined as the species of mycorrhizal fungi compatible with an orchid and the shape of compatibility links between orchids and fungi are referred to as webs.According to traditional records,the majority of mycobiont in terrestrial orchid mycorrhiza belonged in several certain taxonomic groups of basidiomycetes,and there were specific relationships between orchids and fungi.Subsequent studies indicate a more complex situation.The factors which influence the diversity of orchid mycorrhizal fungi is not exactly known.Trophic styles,geographical differences,environmental conditions,or life stages have been reported to play a role in the fungal diversity.Considering the huge temperate zone and alpine mountains,China has rich terrestrial orchid resources.The Huanglong Valley in Sichuan Province,at an elevation of 3100-3569 meter and 3.5kilometers long,is the largest travertine region in the world.Profuse terrestrial orchids from 30 species in 19 genera were found in this narrow valley.Huanglong Valley is one of the temperate terrestrial orchid distribution centers in China.These orchids grew in two different habitats.One was open shrubs with travertine stream flows;another was relative dense mixed coniferous broad-leaved forests without water flows.Cypripedium flavum,Galearis diantha,Ponerorchis chusua and Phaius delavayi were the main orchid species found in open shrub habitat with abundant individuals.Tipularia szechuanica,Platanthera minutiflora,Corallorhiza trifida and Neottia acuminata were the dominant orchid species in forest habitat,the latter two species were myco-heterotrophic,which rely on mycorrhizal fungi throughout their lifetime.From a conservation perspective,this study investigated the diversity of mycorrhizal fungi of temperat wild orchids in the Huanglong Va

关 键 词：温带兰科植物 菌根真菌 多样性差异 专一性 子囊菌 

分 类 号：Q948[生物学—植物学]