CHARACTERIZATION AND RELATIVE CONTRIBUTION OF FUNGAL AND BACTERIAL PATHOGENS INVOLVED IN SUDDEN DEATH SYNDROME OF CHILLIES

Abstract

In the present study, bacterial and fungal agents involved in sudden death syndrome (SDS) in chillies and their relative contribution in the development of disease complex were investigated. Out of eight microbial agents isolated from wilted chilli plants, three pathogenic species viz. Ralstonia solanacearum, Fusarium oxysporum and Rhizoctonia solani were identified and characterized depending upon their morphological, cultural and biochemical behavior. These isolates induced wilting, when inoculated on susceptible chilli cultivar California Wonder under greenhouse conditions. All the pathogens induced wilt symptoms; however, the wilting was more rapid in case of R. solanacearum followed by F. oxysporum and R. solani. Disease symptoms were more prominent when three pathogens inoculated in combinations. However, R. solanacearum and R. solani intriguingly, showed no symptoms even after thirty days of inoculation upon repeated trials. On the other hand, the interactive studies of three pathogens indicated that the symptoms development and seedlings mortality were higher than the rest of combinations or by the individual pathogen.