云南轿子山腋花杜鹃菌根多样性研究

Mycorrhizal diversity of Rhododendron racemosum Franch.in Yunnan Jiaozi Mountain

以云南轿子山野生的腋花杜鹃为研究对象,利用石蜡切片、根系透明染色,观察腋花杜鹃菌根的解剖结构,检测菌根的侵染率及研究根系共生菌根真菌的形态多样性;采用形态鉴定的方法研究根际土壤AM真菌的物种多样性;采取形态学结合rDNA ITS序列测序方法,研究杜鹃植物根系共生真菌的物种多样性。结果表明:轿子山腋花杜鹃的菌根真菌具有3种类型:杜鹃花类菌根真菌(ERM)、丛枝菌根(AM)真菌及暗色有隔内生真菌(DSE);菌根侵染率与AMF孢子密度之间的相关性是0.884,呈显著的正相关关系;其中从土壤样品中分离鉴定出4属5种AMF孢子,分别为瑞氏无梗囊霉(Acaulospora rehmii),大巨孢囊霉(Gigaspora gigantea),布氏球囊霉(Glomus brohultii)和沙生球囊霉(Glomus arenarium),美丽盾巨孢囊霉(Scutellospora calospora);从腋花杜鹃中共分离出1株与杜鹃花类菌根真菌Cryptosporiopsis ericae,1株与根相关的真菌,2株菌根真菌共生真菌Dreschlera sp.,Periconia sp..

To study the morphological diversity of root symbiotic mycorrhizal fungi of wild Rhododendron racemosum Franch.,the anatomic structure and colonization rate of the mycorrhizal root were observed with paraffin section and root transparent staining.The species diversity of AM fungi in rhizosphere soil was studied by morphological identification method.The species diversity of rhododendron root symbiotic fungi was observed with morphology combining rDNA ITS sequences.The results showed that there were three types of mycorrhiza of R.racemosum,ericoid mycorrhizas(ERM)fungi,arbuscular mycorrhizas(AM)fungi and dark septate endophytes(DSE).The correlation between root mycorrhizal infection rate and AMF spore density was 0.884,which showed a significant positive correlation.The strains isolated from soil samples of wild R.racemosum belonged to 4 genus and 5 species,which were Acaulospora rehmii,Gigaspora gigantea,Glomus brohultii,Glomus arenarium,Scutellospora calospora.And a mycorrhizal fungi Cryptosporiopsis ericae,a root-associated fungus,and two mycorrhizal fungi symbiotic fungis,Dreschlera sp.and Periconia sp.were isolated.