广西野生黄花蒿根际土壤AM真菌类型调查分析
Investigation on types of AM fungi in rhizosphere soil of wild Artemisia annua L. in Guangxi
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摘要: 目的调查广西野生黄花蒿根际土壤丛枝菌根(Arbuscular mycorrhizae,AM)真菌与野生黄花蒿的共生情况及其根际土壤理化性状差异,为筛选对广西野生黄花蒿生长有明显促进作用的高效菌株及推动AM真菌在黄花蒿生产上的应用提供理论依据.方法采集野生黄花蒿根际2~30 cm土样,分别测定土壤pH、有机质碳、速效磷、碱解氮和速效钾含量,采用湿筛倾析—蔗糖离心法分离AM真菌孢子,观察记录孢子数量、形态并进行AM真菌类型划分和鉴定.结果不同采样点的野生黄花蒿均被AM真菌侵染,对野生黄花蒿的侵染率在29.15%~40.43%,其中崇左市土样的侵染率最高,南宁马山县土样的侵染率最低;10 g风干土样中的孢子数量以崇左市的最高(163个),百色田林县的最低(32个);不同样点的侵染强度为2~3级,属中等偏下水平.不同样点的土壤pH在7.61~8.38,属弱碱性土壤;土壤有机质碳含量为5.15~58.08 g/kg,速效磷、碱解氮和速效钾含量分别为54.71~551.20、98.70~595.00和66.89~547.30 mg/kg,不同样点间差异明显.AM真菌孢子密度、种类丰度(SR)和物种多样性指数也因采样点不同而存在明显差异.从9个地区55份土样中共分离出42种不同种类的AM真菌.结论广西野生黄花蒿根际AM真菌的分布因地理位置不同而存在差异,与土壤营养状况基本呈反比.野生黄花蒿根际土壤环境差异可能是造成AM真菌多样性的重要原因.Abstract: 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.