柴达木盆地中西部土壤中暗色丝孢菌群落多样性分析

Diversity of soil dematiaceous hyphomycetes from central and western Qaidam Basin,Qinghai Province

从柴达木盆地中西部采集土样59份,涵盖的生态类型有:沙漠、戈壁、湿地、小镇-绿洲等。分离获得暗色丝孢菌108株,经鉴定分属于15属。利用种群优势度、Shannon-Wiener多样性指数、物种均匀度、生态位宽度四项指数,对柴达木盆地中西部不同生境土壤中的有关暗色丝孢菌物种(属级)进行物种多样性分析。结果表明,该地区土壤中暗色丝孢菌的物种优势度存在明显差异:沙漠生境中,链格孢属Alternaria和细基格孢属Ulocladium真菌优势度较高;戈壁生境中,单格孢属Monodictys真菌的优势度最高;湿地和小镇-绿洲生境中,则分别以瓶霉属Phialophora和枝孢属Cladosporium真菌占优势。在小镇-绿洲生境中,土壤暗色丝孢菌的Shannon-Wiener多样性指数最高,均匀度较低;而在沙漠和戈壁生境中多样性指数明显较低,而物种的均匀度较高。在上述四类生境中,链格孢属Alternaria和细基格孢属Ulocladium真菌具有较宽的生态位,为广适性物种;而平脐蠕孢属Bipolaris、卷旋孢属Cirrenaria、弯孢属Curvularia、矛束霉属Doratomyces、粘束孢属Graphium、漆斑霉属Myrothecium、齿梗孢属Scolecobasidium、帚霉属Scopulariopsis、节隔孢属Scytalidium和葡萄穂霉属Stachybotrys10个属真菌的生态位较窄,为狭适性物种。

One hundred and eight isolates of soil dematiaceous hyphomycetes belonging to 15 genera were found from 59 soil samples collected in central and western of Qaidam Basin covered with desert, gobi, swamp and town-oasis. The species dominance, Shannon-Wiener index, evenness and niche width were used to study the diversity of soil dematiaceous hyphomyeetes in different ecosystem of Qaidam Basin. The results showed that the species dominant in the four ecosystem types was distinctly different. In desert ecosystem, Alternaria and Ulocladium were more dominant than other genera; Monodictys had the highest dominance in gobi; Phialophora and Cladosporium had the highest dominance in swamp and town-oasis. The diversity index of soil dematiaceous hyphomycetes was the highest but the evenness was lower in town-oasis, whereas in desert and gobi the diversity obviously lower, and the species evenness was higher. In the four ecosystem types, species of Alternaria and Ulocladium niche breadth and were of widely adaptive species, while species of Bipolaris, Cirrenaria, Curvularia, Doratomyces, index was had wider Graphium, Myrothecium, Scolecobasidium, Scopulariopsis, Scytalidium and Stachybotrys had narrower niche breadth and were of narrowly adaptive species.