广西红壤区甘蔗根际土壤丛枝菌根真菌种类的 18S rDNA 基 因序列分析鉴定及多样性分析

为探明广西红壤区甘蔗根际土壤丛枝菌根（Arbuscular mycorrhizal，AM）真菌多样性特点，本研究通过 18S rDNA 基因序列分析对来自广西红壤蔗区 33 个样地的甘蔗根系和根际土壤样品的 AM 真菌种属进行了鉴定，并分析了 土壤理化性质对 AM 真菌侵染率和多样性的影响。结果表明：3 类红壤类土壤中，赤红壤的根外菌丝量、根内菌丝和 丛枝平均侵染率最高，分别为 13.59%、24.18%、1.29%；砖红壤的泡囊平均侵染率最高，为 19.17%。所构建的 AM 真 菌克隆文库中共发现了 24 个 OTU，分别属于 AM 真菌的 7 科 12 属 24 种，其中球囊霉科含 5 属 10 种，多样孢囊霉科 含 1 属 2 种、无梗囊霉科含 1 属 1 种、巨孢囊霉科含 2 属 2 种，近明囊霉科含 1 属 5 种，原囊霉科和类球囊霉科各含 1 属 2 种；3 类土壤的优势科和优势属分别为球囊霉科和根生囊霉属。红壤的 AM 真菌物种丰富度和香浓维纳指数最高， 砖红壤最低。3 类土壤的理化因子与 AM 真菌的物种丰富度均无显著相关。3 类土壤的根内菌丝侵染率与 pH 值均呈正 相关，与有机质、总氮及有效磷含量呈负相关。

Arbuscular Mycorrhizal Fungal Diversity and 18S rDNA Gene Sequence Analysis and Identification in Rhizosphere of Sugarcane in Red

In this study, a total of 33 soil samples were collected from the rhizosphere of sugarcane plants grown in red soil area of Guangxi. Arbuscular mycorrhizal (AM) fungal community was investigated by molecular identification, and the influencing factors were analyzed. Results showed that the amount of external hyphae, internal hyphae and infection rate of arbuscular were the highest in latosolic soil, with the value of 13.59%, 24.18%, and 1.29%, respectively. Vesicle infection rate was the highest in laterite (19.17%). A total of 24 AM fungal OTUs (operational taxonomic units) were detected in the AM fungi cloning library, which belonged to 7 families, 12 genera and 24 species including Glomeraceae with 5 genera and 10 species, Diversisporaceae with 1 genera and 2 species, Acaulosporaceae with 1 genera and 1 species), Gigasporaceae with 2 genera and 2 species, Claroideoglomeraceae with 1 genera and 5 species, Archaeosporaceae with 1 genera and 2 species, and Paraglomaceae with 1 genera and 2 species. Glomeraceae and Rhizophagus were the dominant families and generas in the three types of soil. The highest level of richness and Shannon-Wiener index of AM fungi were found in red soil, while the lowest was observed in latosols. There was no significant correlation between AM fungi species richness and soil chemical properties in the three types of soil. The infection rate of internal hyphae in the three types of soil was positively correlated to pH and negatively correlated to organic matter, total nitrogen and available phosphorus.