Bacterial and fungal communities, but not physicochemical properties, of soil differ according to root rot status of pea

Abstract

AimsField pea (Pisum sativum L.) is an important rotation crop in agriculture on the Canadian prairies. Pea root rot is caused by a complex of soilborne pathogens, and can have a tremendous impact on reducing yields and removing fields from pea production. The objectives of this study were to: determine whether characteristics of the fungal and bacterial microbiome are associated with diseased or healthy sites within pea fields, and assess whether abiotic soil properties differed between these diseased or healthy sites. MethodsSoil was collected from healthy and diseased sites within 5 fields across Alberta. Bacterial and fungal operational taxonomy units were determined using barcoded Illumina MiSeq of the 16S rRNA and internal transcribed spacer 1 (ITS) genes, respectively. Soil enzyme activities and soil physicochemical properties were also measured. ResultsPrincipal coordinate analysis showed that health status was an important determinant of bacterial communities in two out of five fields and fungal communities in all fields. Microbial communities also differed between locations. However, there was no clear relationship between specific fungal or bacterial families, enzyme activities or soil properties with root rot status. ConclusionsAlthough root rot severity and fungal community composition varied between healthy and diseased sites within a field, there was no consistent correlation of disease severity with biotic or abiotic soil properties across locations.