Botryodiplodin (A Mycotoxin) detection in pathogenic Botryodiplodia theobromae isolated from diseased coconut fruits

Abstract

Botryodiplodia theobromae is a threat to crops because it produces botryodiplodin, that plays a role in the initial stages of plant infection, creating necrotic areas through which it can easily penetrate. In addition, the botryodiplodin produced is not easily detected during quarantine, and other techniques developed to detect botryodiplodin are not easily practicable for screening numerous samples. Hence, the need to develop an in-culture pigment formation method to identify and differentiate toxigenic and non-toxigenic pathogenic isolates of B. theobromae. In this study, to detect botryodiplodin produced by isolates of B. theobromae, PDA, CDA and modified CDA media were used. Only the modified CDA medium enhanced the detection of botryodiplodin produced by B. theobromae isolates due to the addition of glycine into the medium. The effect of modified CDA composition or formulation, sucrose, and glycine concentrations on botryodiplodin detection were also evaluated. Study on the effect of the modified CDA composition on the detection of botryodiplodin produced by isolates of B. theobromae revealed that only sucrose stimulated the detection of botryodiplodin in comparison with other ingredients in the modified medium. In addition, the results from the study also reveals that increasing sucrose and glycine concentrations directly enhanced botryodiplodin detection, with optimum concentration of sucrose and glycine for detecting botryodiplodin by isolates of B. theobromae established at 15 and 10 g/l respectively. Hence, there is no need to increase the concentration of both sucrose and glycine above these established concentrations when preparing an in-culture medium for screening B. theobromae isolates capable of producing botryodiplodin.