摘要
[目的]研究浙贝母器官内生菌群,以期探明浙贝母道地性的形成机制,为开发其潜在的内生菌资源提供理论依据。[方法]本实验用PCR-变性凝胶梯度电泳(DGGE)对浙贝母的根、鳞茎、地上茎以及叶中的内生菌多样性和组成进行了检测和分析。[结果]DGGE结果表明,浙贝母不同器官中的内生菌多样性和结构均有差异。根部条带明显比其它器官多,内生细菌多样性指数最高(2.69),而且出现不少特异性条带;茎中的细菌多样性为2.44;叶中最低,仅2.21。测序结果表明,浙贝母中的内生细菌主要为蓝细菌、根瘤菌、睾丸酮假单胞菌、伯克氏菌属和燕麦噬酸菌,后两种菌均为β-变形菌,该菌的存在可能会对浙贝母的生长产生不利影响,而根瘤菌和丛毛单胞菌则对其生长有利。根部特异性细菌包括蓝细菌(B4)、伯克氏菌属(B23)、根瘤菌(B5、B24)以及3种不可培养细菌(B6-B8)。与细菌相比,内生真菌DGGE图谱在不同器官之间的差异更小,大部分为共有条带,只是亮度有差异。当然也有特异条带,如曲霉属(F10)仅在鳞茎中出现。镰孢菌属(F11)以及2种不可培养的真菌(F5、F6)为根部特有。与细菌不同,地上茎中的真菌Shannon指数最高(2.82),其次是鳞茎和根,叶最低2.53。利用DGGE检测到浙贝母的内生真菌主要为侧齿霉、镰孢霉和曲霉,而利用传统方法还分离到交链孢霉、青霉、拟茎点霉、葡萄孢、卵形孢霉、枝链孢霉、毛壳菌、丝核菌以及束丝菌等属,说明对浙贝母而言,传统方法更适合。[结论]浙贝母不同器官中内生细菌和真菌的多样性及组成均存在差异,但地下鳞茎和地上茎差异较小;真菌的器官差异不如细菌明显。浙贝母内生菌的分布跟其它植物明显不同,其菌群组成主要取决于浙贝母宿主植物本身。不同的内生菌占据不同生态位,执行不同功能,有的对促进浙贝母的生长,而有的则影响生长,其中侧齿霉属值得进一步研究。
[Objective]As a kind of important microorganism resources,endophytes communities in Fritillaria thunbergi helps to know the mechanism of geoherblism and find talent microbial resources.[Methods] Here we applied polymerase chain reaction-denatured gradient gel electrophoresis（PCRDGGE） for studying the diversity and composition of endophytes in four organs of F.thunbergii.[Result] DGGE results showed obvious differences in diversity and structure of endophyte in Vegetative Organs of F.thunbergii.Among these organs,root showed the most bands and the highest Shannon index of bacteria（2.69）,followed by stem（2.44） and leaves（2.21）.The dominant endophytic bacteria were Thermosynechococcus elongatus,Rhizobium,Comamonas testosteroni,Burkholderia and Acidovorax avena.Rhizobium and Comamonas testosteron may be beneficial to the growth of F.thunbergii,while Burkholderia and Acidovorax avena had the opposite effect which both belonged to β-Proteobacteria.Root demonstrated some specific endophytic bacteria including Cyanobacteria（B4）,Burkholderia（B23）,Rhizobia（B5,B24） and three uncultured bacterium（B6-B8）.The results of endophytic fungus showed less variation in different organs than that of bacteria.Most bands were just in common in all organs but with different brightness.Of course,there were also specific bands such as Aspergillus（F10） which only appeared in bulb.Fusarium（F11） and two uncultured fungi（F5,F6） were only in root.Shannon index of fungus in stem was the highest（2.82）,followed by the bulb and root and leaves showed the lowest level（2.53）.Cluster analysis showed that underground bulb and sterns clustered together for their similarity.In addition,DGGE results showed that endophytic fungi in F.thunbergii comprise Engyodontium,Fusarium and Aspergillus,meanwhile the traditional methods detected Fusarium,Aspergillus,Penicillium,A lternaria,Botrytis,Phomopsis,Oospora,Chaetomium,Rhizoctonia and Ozonium,which indicated the culture method was more suitable for fungi than DGGE.[Conclusion] The diversity and composition of endophytes differed from different organs of F.thunbergii,while the bacteria showed more obvious differences than that of fungi and no significant difference was observed between underground bulb and stem.The distribution of endophytes in F.thunbergii was different from other plants,indicating that the composition of endophytic flora was determined mainly by the host plant.Each endophyte acted its ecological niche and serving different functions,some of which were beneficial to F.thunbergii while some not.The genus Engyodontium need further study to explore its correlation with F.thunbergii.
出处
《浙江中医药大学学报》
CAS
2014年第9期1091-1097,1102,共8页
Journal of Zhejiang Chinese Medical University
基金
国家自然科学基金项目(81102754)
第53批中国博士后科学基金(2013M531484)
浙江省博士后科研项目(BSH1301033)~~
关键词
浙贝母
PCR-DGGE
内生细菌
内生真菌
Shannon指数
聚类分析
Fritillaria thunbergi
PCR-DGGE
vegetative organ
endophytic bacteria
endophytic fungi
Shannon index
clustering analysis
