Clubroot disease in soil: An examination of its occurrence in chemical and organic environments

Abstract

Clubroot is a disease in cruciferous plants caused by the soil-borne pathogen Plasmodiophora brassicae. This pathogen rapidly spreads in soil, and plant growth is inhibited by infection with spores. In this study, the development of clubroot disease in Brassica rapa var. perviridis was investigated in different soil environments (chemical and organic soils). The bacterial biomass and diversity of the soil and roots were also analyzed in both chemical and organic soils. Bacterial biomass and diversity in the organic soil were higher than those in the chemical soil. The disease severity of plants cultivated in organic soil was lower than that in chemical soil. The number of endophytic bacteria in the roots decreased when the plants were infected with P. brassicae in both soil types. Higher bacterial biomass in the soils and roots appeared to reduce the infection of P. brassicae. ImportancClubroot is a major disease of cruciferous plants caused by soil borne pathogen Plasmodiophora brassica. Pesticides are applied in the soil during cultivation for the inhibition of clubroot disease, which demise soil microbiome. Therefore, eco-friendly control methods are required for sustainable cultivation. Soil management is an important strategy to inhibit clubroot disease severity. In this study, the occurrence of clubroot disease in B.rapa were compared in two distinct soil environments (chemical and organic). Results show infection rate increased with the increase of spore number for both chemical and organic soil environments. However, the diseases severity was lower in plants cultivated in organic soil. The higher endophytic bacterial biomass and diversity seems to be linked for the disease inhibition in organic plants. These findings suggest a sustainable soil management process to reduce clubroot disease prevalence. Application of organic fertilizers in commented soils could substantially reduce clubroot disease severity in the plants.