Pathogenicity variation, morphological and cultural characteristic of Lasiodiplodia theobromae isolates
R Logeshwari, R Udhayakumar, A Muthukumar, K Ganesh Saravanan
The stem end rot caused by Lasiodiplodia theobromae is one of the most common and serious diseases of mango. In the present study, the pathogenicity variation of L. theobromae was assessed by Pin-prick method, spore injection method and mycelial inoculation method. The data revealed that the level of pathogenicity varied between the isolates. Among the seven isolates of L. theobromae, the isolate LT6 recorded the maximum disease incidence of 81.94 per cent in pin prick method, 73.82 per cent in spore injection method and 62.91 per cent in mycelial inoculation. In the morphology and culture character assessment, the isolate of L. theobromae showed variability with respect to colony characters. Most of the isolates produced greyish black on the PDA medium in Petri dishes. The pigmentations like greyish black, grey, blackish were predominant in isolates. Among the isolates of L. theobromae, the maximum mycelial growth (90.00 mm) was recorded by the isolates LT6 followed by LT5 recorded 88.37 mm each at three days after inoculation. All the isolates of L. theobromae varied in their ability to produce pycnidia on PDA. The pycnidial population was found to be excellent with LT6 isolate.
R Logeshwari, R Udhayakumar, A Muthukumar, K Ganesh Saravanan. Pathogenicity variation, morphological and cultural characteristic of Lasiodiplodia theobromae isolates. International Journal of Botany Studies, Volume 7, Issue 3, 2022, Pages 48-52