A new insight into spacing patterns of soil bacterial microbiome induced by root rot of Carya cathayensis

Abstract

The sustainability of tree crop plantations has become an urgent issue due to the frequent incidence of soil-borne plant diseases. Root rot is a soil-borne disease that can result in severe losses of Carya cathayensis, an economically important plant. However, the disease's transmission characteristics and impact upon the resident bacterial community are poorly known. This study analyzed the microbial communities in bulk and rhizospheric soils over equal geographical distances (4 m) using high-throughput sequencing to explore the transmission pattern and biotic and abiotic driving factors of root rot. The results revealed that available potassium, phosphatase enzyme, and pH were negatively related to root rot incidences. In addition, microbial α-diversity showed opposite variations in bulk and rhizospheric soils but ultimately recovered to the initial healthy levels (P > 0.05), while bacterial structure showed no resilience. In comparison, specific taxa, such as Flavobacterium in bulk soil and Nitrolancea, Microvirga in rhizospheric soil, increased rapidly with rising disease incidences. Besides, rhizospheric communities were involved in a stabler but a less resistant network of disease incidences than bulk soil. This study expands our knowledge of the distance pattern of root rot transmission between plant rhizosphere and soil microorganisms as well as the biotic and abiotic factors driving disease incidences, ultimately offering potential strategies to suppress root rot disease and improve soil health.