黄河三角洲土壤真菌群落结构对盐生植被演替的响应

采用高通量测序技术,探究了黄河三角洲光板地和4种盐生植被(翅碱蓬、獐茅、白茅和罗布麻)下土壤真菌群落结构组成及分布特征,揭示其与盐生植被演替的关系.结果表明,随盐生植被正向演替,土壤质量有不断改善的趋势.轻度耐盐群落(罗布麻群落、白茅群落)土壤中真菌丰富度相对较高,其Shannon多样性指数分别为5.21、5.84;在重度耐盐群落(翅碱蓬、獐茅)土壤中真菌丰富度较低,其Shannon多样性指数分别为4.64、4.66.在不同演替阶段时,土壤真菌群落结构差别相对较大(Unifrac Metric值为0.48~0.67).土壤中全氮含量是影响真菌OTU数、ACE指数和Shannon指数的主要因素.5个土壤样本共获得60174条有效序列,可归到子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、壶菌门(Chytridiomycota)、球囊菌门(Glomeromycota)、毛霉亚门(Mucoromycotina)5个真菌门;其中,子囊菌门在重度耐盐植物群落(翅碱蓬、獐茅)中相对丰度较高(2.69%、69.97%),担子菌门在轻度耐盐群落(罗布麻群落、白茅群落)中相对丰度较高(9.43%、6.64%).

Response of soil fungal community structure to halophytic vegetation succession in the Yellow River Delta

High-throughput sequencing technology was used to investigate fungal community structure in Bare land and soils from four halophytic vegetation types, i.e.,-Saline Seepweed, Angiospermae, Imperata cylindrica and A. venetum L, over the Yellow River Delta. The relationship between spatial patterns of fungal community structure and halophytic vegetation succession was also examined. The soil quality tended to increase when the succession of halophytic vegetation types was positive. Soils from the moderately salt tolerant Imperata cylindrica and A. venetum L communities often had relatively high fungal richness, with Shannon indexes of 5.21 and 5.84, respectively, while fungal richness in soils from severely salt tolerant Saline Seepweed and Angiospermae communities were relatively lower, with Shannon index of 4.64 and 4.66, respectively. Fungal community compositions in soils significantly varied from one succession stage to another, with the unifrac metric values between 0.48 and 0.67. The content of total nitrogen in soil was the main factor affecting the OTU numbers, ACE index and Shannon index of fungi. 60174 valid sequences were obtained from 5 vegetation types, i.e. Ascomycota, Basidiomycota, Chytridiomycota, Glomeromycota and Mucoromycotina. Ascomycota was a dominant community in severely salt tolerant plant Saline Seepweed and Angiospermae communities, with the relative abundance of 2.69% and 69.97%, respectively. Basidiomycota was dominated in moderately salt Imperata cylindrica and A. venetum L. communities, with the relative abundance of 9.43% and 6.64%, respectively.