Characterization of Cultural and Morphological Variability in Rhizoctonia solani Isolates Associated with Root Rot of Ajwain (Trachyspermum ammi L.)

Rhizoctonia solani (teleomorph: Thanatephorus spp.) is a plant pathogenic fungus which had a wide host range. It is best known to cause many diseases in plants such as collar rot, root rot, damping- off, sheath blight, stem canker, web blight and wire stem throughout the world. In vitro study of the various isolates of R. solani for morphological and cultural characters and results revealed that this experiment the various isolates of R. solani differed in colony characters and showed black brown colored cultures with 90.0 mm colony diameter on 7th day of incubation under uniform environmental condition. The highest growth reported was isolates CHIRs-5 and sclerotial formation was recorded in all the isolates of R. solani. Morphology of sclerotia varied from 1.9×1.5 mm of DCHIRs-1 and 1.8×1.5 mm of RUDPRs-2.