为探究大石围天坑群深色有隔内生真菌(DSE)资源并发掘其生态功能,采用白菜为诱饵植物对广西大石围天坑群原始森林土样中的DSE菌株进行诱捕分离,并结合形态学特征观察和ITSl-5.8S-ITS4-28S rDNA基因序列分析进行鉴定;从中选择4株DSE菌株接种当地先锋植物,进行自然干旱胁迫实验,并测定植株萎蔫指数、恢复浇水后的萎蔫率和相关生理生化指标.共从土样中分离筛选获得22个DSE菌株,分属Exophiala、Chaetothyriales、Aspergillus、Oidiodendron、Tetracladium、Schizothecium、Camarops、Chaetomium等13个属,呈现出丰富的物种多样性.干旱胁迫下,菌株TK566和TK731能在一定程度上提高任豆(Zenia insignis)和苏木(Caesalpinia sappan)这两种当地石漠化修复先锋树种幼苗的抗旱和生长能力.由于内生真菌-植物互作方式非常复杂,DSE是否从酶系统调控层面来影响植物的抗旱性则仍需进一步研究.本研究结果表明大石围天坑群DSE资源丰富,且部分菌株对提高植物抗旱性和生长具有正向作用,具有良好的开发利用潜力.%In order to investigate dark septate endophytic fungi (DSE) resources in Dashiwei doline group (DDG) and explore their ecological functions,DSE strains were trapped and isolated from primeval forests soil samples in DDG using Chinese cabbage.Identification was conducted based on the morphological characteristics and analysis of ITS1-5.8S-ITS4-28S rDNA gene sequences.And selected four DSE strains to inoculate local pioneer plants,and car ried out natural drought coercion experiment,then tested the plants' flaccidity indices,flaccidity ratio,and related physiological and biochemical norm.22 DSE strains were isolated and obtained from soil samples.They belong re spectively to 13 genera of Exophiala,Chaetothyriales,Aspergillus,Lophiostoma,Oidiodendron,Hyphodiscus,Tetracladium,Phlogicylindrium,Nectria,Zalerion,Schizothecium,Camarops,Chaetomium and show abundant species diversity.Under drought coercion,strain TK566 and TK731 could enhance to a certain degree to repair the drought tolerance and growth capability of Zenia insignis and Caesalpinia sappan these two local pioneer plants under rock desertification.However,because of the complexity of the mutual effect mode between endophytic fungi and plants,further investigations are needed to figure out whether the drought resistance is affected by DSE through enzymatic system regulation level.The results of the study suggested that DSE resources in DDG are abundant and some of them possess positive effects for plants' drought tolerance and growth,and showed fine perspective for their development and utilization.
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