蒙古沙冬青AM真菌物种多样性与土壤因子的相关性

Spatio-temporal distribution of arbuscular mycorrhizal fungi in the rhizosphere of Ammopiptanthus mongolicus

为了探明蒙古沙冬青（Ammopiptanthus mongolicus）根围AM真菌物种多样性年际变化规律以及土壤因子的生态功能,于2012年7月和2013年7月从宁夏银川、沙坡头和甘肃民勤3个样地分别从O～10,10～20,20～30,30～40,40～50 cm 5个土层对沙冬青根围土样进行采集,共分离鉴定出AM真菌5属36种,其中,球囊霉属Glomus 16种,无梗囊霉属Acaulospora 13种,管柄囊霉属Funneliformis 3种,盾巨孢囊霉属Scutellospora 3种,多孢囊霉属Diversispora 1种.不同样地和土壤深度,AM真菌种类组成、孢子密度和种丰度在年际间均有明显差异.相关性分析表明,孢子密度与土壤酸性磷酸酶和总球囊霉素显著正相关;种丰度与土壤脲酶、有机质和碱解氮显著正相关.主成分分析表明,土壤有机质、碱解氮、速效磷、速效钾、脲酶、碱性磷酸酶是影响AM真菌物种多样性的主要因子.研究结果说明,AM真菌物种多样性及其分布规律可以用作检测和评价荒漠环境土壤状况的生态指标.

In order to explore the relationship between the annual variation of AM fungal species diversity and ecological functions of soil factors in the rhizosphere of Ammopiptanthus mongolicus, soil samples in the rhizo- sphere of A. mongolicus were collected from three samples sites （Yinchuan, Shapotou and Minqin） and divided in- to five layers on the basis of depth, from top to bottom. 0-10, 10-20, 20 30, 30-40, 40-50 cm in July 2012 and 2013. In this study, 36 species of AM fungi were isolated from five genera isolated in three sampling sites. Among them, 16 species belonged to Glomus, 13 to Acaulospora, three to Funneliformis, three to Scutel-lospora and one to Diversispora. AM fungal species composition, spore density and species richness were signifi- cantly different between different years and different layers. AM fungal species diversity was closely related to the soil environments. The correlation analysis showed that spore density had a significant positive correlation with soil acid phosphatase and total glomalin, species abundance had a significant positive correlation with soil urease, organ- ic matter and available N. The results showed that the AM fungal species diversity had obvious spatial heterogenei- ty and closely related with soil environments. AM fungal species diversity and distribution could be used as an eco- logical indicator to detect and evaluate the desert environment state.