青岛胶州湾四种类型湿地AM真菌多样性

Diversity of arbuscular mycorrhizal fungi in four wetland of Jiaozhou Bay in Qingdao, China

对青岛胶州湾4种类型湿地(盐田、滩涂、湖泊和河口)中芦苇Phragmites communis、香蒲Typha orientalis和碱蓬Suaeda glauca根围土壤中丛枝菌根(arbuscular mycorrhizal,AM)真菌进行孢子分离与鉴定,分析湿地生态系统中植物根围AM真菌群落特征。共分离到AM真菌5属10种,包括斗管囊霉属Funneliformis 2种、无梗囊霉属Acaulospora 3种、近明球囊霉属Claroideoglomus 2种、球囊霉属Glomus 1种、巨孢囊霉属Gigaspora 2种,其中,斗管囊霉属Funneliformis及地斗管囊霉Funneliformis geosporum的分离频度和相对多度最高,分别为湿地中AM真菌优势属和优势种。滩涂和河口湿地中植物AM真菌侵染率显著高于湖泊和盐田湿地植物,AM真菌孢子密度以滩涂湿地最高(572个/20mL),湖泊湿地最低(220个/20mL);滩涂湿地的种丰度和Shannon-Wiener指数最高,分别为3.8和1.2。从植物种类来看,AM真菌侵染率总体呈现出香蒲>碱蓬>芦苇,AM真菌孢子密度以香蒲最高,芦苇最低,植物种类对AM真菌种丰度和Shannon-Wiener指数影响不显著(P>0.05)。二因素方差分析和典型RDA相关分析表明,寄主植物种类对AM真菌孢子密度有一定影响,但湿地类型对AM真菌多样性的影响更为显著(P<0.05),胶州湾湿地土壤因子Ca^2+、速效P含量与AM真菌孢子密度、物种丰度和多样性指数显著负相关,而速效K、Na^+、pH与其显著正相关。结果表明植物种类主要影响AM真菌孢子密度,AM真菌多样性受植物种类和湿地类型综合影响,滩涂湿地较丰富的AM真菌多样性可能与该湿地较良好的理化性质有关。

Diversity of arbuscular mycorrhizal(AM)fungi in the rhizosphere of Phragmites communis,Typha orientalis,and Suaeda glauca grown in salt fields,tidal flats,lakes and estuaries in Jiaozhou Bay of Qingdao were investigated based on spore isolation and identification.A total of 10 species of five genera of AM fungi was isolated,including two species of Funneliformis,three species of Acaulospora,two species of Claroideoglomus,one species of Glomus,and two species of Gigaspora.The frequency and relative abundance of Funneliformis and Funniliformis geosporum were the highest,which were dominant genus and species of AM fungi in the wetlands tested.The AM fungal colonization rate of plants grown in tidal flats and estuarine wetland was significantly higher than that in lake and salt fields.The highest spore density of AM fungi appeared in tidal flat wetlands(572/20mL),while the lowest in lake wetlands(220/20mL);the species richness and the Shannon-Wiener index in tidal flats were the highest,being 3.8 and 1.2 respectively.AM fungal colonization percentage increased progressively in order of T.orientalis>S.glauca>P.communis.The spore density of AM fungi was highest in rhizosphere of T.orientalis and lowest in that of P.communis,manifesting that the plant species had no significant effect on the AM fungal species richness and Shannon-Wiener index(P>0.05).Two-factor analysis of variance and analysis of variance and the typical RDA correlation analysis showed that the soil factor Ca^2+and available phosphorus content in Jiaozhou Bay wetland were significantly negatively correlated with the AM fungal spore density,species richeness and diversity index(P<0.05),while the available potassium content,Na^+and pH showed positive correlation.It is concluded that plant species mainly affect spore density of AM fungi,and the diversity of AM fungi is multiply affected by plant species and wetland types.The relative richness of species diversity of AM fungi in tidal flat wetland might be related to relatively suitable physicochemical properties of Jiaozhou Bay wetland in Qingdao.