Rapid and sensitive detection of Sclerotium rolfsii associated with collar rot disease of Amorphophallus paeoniifolius by species-specific polymerase chain reaction assay.

Collar rot disease caused by Sclerotium rolfsii is an economically important disease prevailing in all Amorphophallus growing areas. The pathogen propagules surviving in soil and planting material are the major sources of inoculum. A nested PCR assay has been developed for specific detection of S. rolfsii in soil and planting material. The PCR detection limit was 10 pg in conventional assay whereas 0.1 pg in nested assay. The primers designed were found to be highly specific and could be used for accurate identification of pathogen up to species level. The protocol was standardized for detection of the pathogen in artificially and naturally infected field samples.