Effects of vanillin on cucumber (Cucumis sativus L.) seedling rhizosphere fungal community composition

Abstract

Cucumber seedlings grown in soil were treated with vanillin at 0.1 μmol/g soil and the cucumber rhizosphere fungal composition was analyzed by high-throughput sequencing of total fungal ITS regions. A total of 207,557 quality fungal ITS sequences were obtained and these sequences were classified into more than 390 OTUs at 97% sequence similarity. Vanillin decreased the number of OTUs, ACE, Chao and Shannon indices of cucumber seedling rhizosphere fungal communities. Principal coordinat analysis showed that vanillin changed the cucumber seedlings rhizosphere fungal community composition. Compared with water-treated soils, vanillin-treated soils had higher relative abundances of phylum Basidiomycota, classes Tremellomycetes and Ascomycota incertae sedis but had lower relative abundances of phylum Zygomycota and classes Sordariomycetes and Zygomycetes (P< 0.05). Moreover, vanillin promoted the relative abundances of several fungal genera, such as Fusarium and Nectria spp., but decreased that of Pseudallescheria spp.