2007年4月、7月和10月分别于陕西省榆林市北部沙地的油蒿(Artemisia.ordosica)根围分0～10 cm,10～20 cm,20～30 cm,30～40 cm和40～50 cm 5个土层采集土壤样品,系统研究了油蒿根围丛枝菌根(Arbuscular mycorrhiza,简称AM)真菌和球囊霉素的时空分布及与土壤因子的相关性.结果表明,油蒿根围AM真菌总定殖率为89.54%、泡囊定殖率为26.24%,丛枝定殖率为21.08%,孢子密度为2.91～6.17个/g土,说明油蒿能与AM真菌形成良好共生关系.从土壤样品中共分离出4属21种AM真菌,其中球囊霉属(Glomus)为优势属,地球囊霉 (G.geosporum)为优势种.油蒿根围AM真菌和球囊霉素具有明显的时空异质性,并与土壤因子密切相关.菌丝定殖率随季节变换逐渐增加,泡囊定殖率和丛枝定殖率在夏季最低,春秋相对较高,与孢子密度季相变化相反.油蒿根围总球囊霉素在0～20 cm 土层含量最高,随土层深度增加而递减.易提取球囊霉素含量随土层深度增加波动较大.球囊霉素春季含量最高,夏秋含量降低.总球囊霉素和易提取球囊霉素与土壤养分、土壤酶活性、AM真菌孢子密度均有极显著相关性,二者能综合反应土壤AM真菌群落、有机C动态和养分循环进程,应作为土壤质量及功能评价的新指标进一步深入研究.%In this paper, the spatio-temporal distribution of arbuscular mycorrhiza (AM) fungi and glomalin in rhizosphere of Artemisia ordosica and its relationship with soil factors were investigated in sand soil north to Yulin city, Shanxi, China. In April, July and October, 2007, soil samples around rhisophere of A.ordosica were collected. Each time, the soil was divided into five layers on the basis of depth from top to bottom: 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm, 40-50 cm, respectively. The results showed that the total colonization rate (89.54%), vesicular colonization rate (26.24%) and arbuscule colonization rate (21.08%) of AM fungi were very high around rhisophere of A.ordosica, and spore number was 2.91-6.17 per gram soil, indicating that AM fungi established well symbiosis with rhisophere of A. ordosica. Twenty-one species of AM fungi in four genera were detected in soil samples, the predominant genera and predominant species was Glomus and G. geosporum, respectively. Distribution of AM fungi and glomalin was remarkably heterogeneous and closely related with soil factors. Hypha colonization increased gradually with season. Vesicular colonization rate and arbuscule colonization rate were at their lowest level in summer and higher in spring and autumn, seasonal variation of spore density was in a reverse pattern. Total extractable glomalin (TEG) was negatively correlated with soil depth, the highest value was in surface (0-20 cm) layer. Easy-extracted glomalin (EEG) content showed a fluctuation with soil depth. The TEG content was high in spring and decreased in summer and autumn. TEG and EEG were remarkably correlated with soil nutrition, soil enzyme activity and spore density of AM fungi, in future research, they can be used as parameters to monitor the development of AM fungi community, organic carbon dynamic and nutrition cycle in sand soil.
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