Investigation on types of AM fungi in rhizosphere soil of wild Artemisia annua L. in Guangxi

ObjectiveSymbiosis of arbuscular mycorrhizal(AM)fungi in the rhizosphere soil of Artemisia annua L. in Guangxi and wild A. annua and the physical and chemical character differences in rhizosphere soil were investigated to provide reference for the exploration of effective strains which could promote the growth of wild A. annua in Guangxi and the application of AM fungi in A. annua production.MethodSoil samples of 2-30 cm in rhizosphere of wild A. annua were collected to determine soil pH,organic carbon,available phosphorus,alkali-hydrolyzale nitrogen and available po-tassium. The spores of AM fungi were separated by wet sieve decantation-sucrose centrifugation method. The number and morphology of spores were observed and recorded,and types of AM fungi were divided and indentified.ResultAll wild A. annuas in different sampling sites were infected by AM fungi. The infection rate of AM fungi on wild A. annua was 29.15%-40.43%,with the infection rate of soil samples in Chongzuo being the highest and that of Mashan,Nanning the lowest. Chongzuo held the largest number of spores(163 spores)in each 10 g air drying soil sample,while Tianlin,Baise held the smallest number(32 spores). The infection intensity in different locations was 2-3 grade,which was at medium and low level. The soil pH in different locations was 7.61-8.38,which belonged to weakly alkaline soil. The organic car-bon content of soil was 5.15-58.08 g/kg. Contents of available phosphorus,alkali-hydrolyzale nitrogen and available po-tassium were 54.71-551.20,98.70-595.00 and 66.89-547.30 mg/kg respectively and showed marked difference among different locations. The spore density of AM fungi,species abundance(SR)and species diversity index greatly varied from different locations as well. Fourty-two different species of AM fungi were separated from fifty-four soil samples in nine regions.ConclusionThe distribution of AM fungi in wild A. annua rhizosphere soil varies from different geographical locations,and it is inversely proportional to the soil nutrition. The environmental differences in rhizosphere soil of wild A. annua could be significant cause to the diversity of AM fungi.