摘要
以极端干旱区塔里木河下游处于干旱胁迫下的天然胡杨为研究对象,采用传统形态鉴定法和分子生物技术,研究了胡杨根围土壤中丛枝菌根真菌。结果表明:处于干旱胁迫下的胡杨根围土壤中丛枝菌根真菌孢子密度较低,且孢子种类单一,经形态鉴定和分子生物学鉴定,孢子为球囊霉属的摩西球囊霉Glomus mosseae(T.H.Nicolson&Gerd.),孢子在土壤中单生、根内生或孢子果内形成;圆形,近圆形,直径150～220μm,浅黄色至黄褐色;孢壁3层,L1和L2无色透明,L3浅黄至黄褐色。连孢菌丝单根,连点漏斗状。胡杨根系内存在丛枝菌根真菌的泡囊结构,分子检测表明摩西球囊霉Glomus mosseae与胡杨根系形成共生关系,但是胡杨根系的菌根侵染率及根系的菌根侵染强度均不高。
In this study,arbuscular mycorrhizal fungi（AMF） of natural Populus euphratica rhizosphere in the lower reaches of the Tarim River was investigated by using traditional morphological methods and molecular techniques.In particular,Nested-PCR was conducted to specifically amplify D1-D2 variable region nucleotide sequences of the small-subunit（25S） rDNA from the AMF in the root and rhizospheric soil samples of Populus euphratica,respectively.The Nested-PCR products were applied to nucleotide sequence analysis and analyzed with phylogenetic analysis.The results indicate that the targeted product（786bp） was successfully amplified from trace DNA by Nested-PCR.Based on the Phylogenetic tree built with DNAMAN software,the nucleotide sequence analysis outcomes were appraised with Bootstraping method.According to the spore morphological properties and molecular analysis results,we know that under drought stress the dominant AMF species was Glomus mosseae in soil.The spore density of AMF within the rhizospheric soil of Populus euphratica was low.Glomus mosseae fungal spores were formed in the soil alone,inside of the roots or sporangium.The shape of the spore is round,or nearly round,with a diameter of 150-220 μm;the color of the spore becomes brown from light yellow;the spore wall has three layers,L1-L3,L1 and L2 are colorless and transparent,L3 is light yellow to brown.The hyphae is single and funnel-shaped at the attachment.There was vesicle structure in the roots observed in the Olympus BX51 microscope,which shows that Mycorrhizal symbiont was established by AMF associated with Populus euphratica root.Further,Glomus mosseae can colonize in the Populus euphratica roots.But the AMF colonization rate and the infection intensity were not significantly high.
出处
《干旱区地理》
CSCD
北大核心
2012年第2期260-266,共7页
Arid Land Geography
基金
中国科学院“西部之光”(RCPY200801)项目
国家自然科学基金项目(91025025,40901061)
西部人才培养计划西部博士专项领域前沿项目(XBBS200907)共同资助
