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

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

为探明广西红壤区甘蔗根际土壤丛枝菌根(Arbuscularmycorrhizal,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。

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 Rhizophaguswere 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.