MORPHOLOGICAL VARIATION IN BOTRYODIPLODIA THEOBROMAE PAT. CAUSING TWIG-BLIGHT AND DIE-BACK OF MANGO

Morphological variation in mango twig-blight and die-back pathogen Botryodiplodia theobromae Pat. was studied in situ in naturally infected and inoculated leaves and twigs and on ten different media viz. Richard's agar, Elliot's agar, Glucose asparagine agar, Czapek's agar, Das Gupta agar, Potato dextrose agar, Oatmeal agar, Brinjal fruit extract agar, Brown's agar and Asthana and Hawker's agar. The size of the immature and mature pycnidia varied greatly with the substrate. The pycnidia were smallest in naturally infected twigs and biggest in nutritionally rich medium such as Oatmeal agar. No such distinct variation was observed in the size of immature and mature conidia. It is suggested from this study that measurement range of mature pycnidia (189–886 x 154–704 μm) should be taken into account for identification of a species.