UNVEILING THE CLUBROOT PATHOGEN PLASMODIOPHORA BRASSICAE: INSIGHTS INTO ITS BIOLOGY, PATHOGENICITY, AND CONTROL STRATEGIES

Abstract

Clubroot is a disaster in the cultivation of crops of the Cruciferae family, caused by an obligate fungus, ( Plasmodiophora brassicae ). This pathogen survives in soil and crop debris for a long time in the form of a double-walled resting spore which is sub spherical to spherical in shape with 3 µm in diameter. Its severity is highest at a pH of 5.7, a cool temperature, and excess moisture. The biotic factors in its severity include the spore count in the soil and its virulence. Its dominant resting spore germinates to produce primary plasmodia. The primary plasmodia infect root cells, producing zoospores, which infect cortical cells and cause hypertrophy. This causes formation of typical club shaped galls in the roots. For its management, an integrated management system of agronomic, biological, and chemical approaches is required. Agronomic strategies include liming to raise pH, Boron application, crop rotation, cultivating resistant varieties, soil solarization, and sanitation. Similarly, biological strategies include use of microbial organisms like Trichoderma spp., Gliocladium catenulatum, Streptomyces sp., Bacillus amyloliquefaciens, and endophytes like Acremonium alternatum and Heteroconium chaetospira. Finally, chemical approach includes the use of fungicides like cyazofamid, Penta Chloro Nitro Benzene (PCNB), Nano Silver Hydrogen Peroxide