Characterizations of Ganoderma species causing basal stem rot disease in coconut tree

The basal stem rot disease incidence ranged from 0 to 5% in Karnataka India during the year 2019-20. Twenty pathogenic isolates of Ganoderma sp varied with cultural characteristics and virulence on coconut seedlings of the variety Tipatur Tall. The identity of each isolate was confirmed through morphological characters and through ITS sequencing. Two isolates viz., G₄ and G₅ were identified as Ganoderma applanatum and remaining all isolates were identified as G. lucidum. The genetic diversity analysis of Ganoderma isolates was done using ten Random Amplified Polymorphic DNA (RAPD) and fifteen Inter Simple Sequence Repeat (ISSR) primers. Among the ten RAPD primers, only eight primers recorded polymorphism (33.30-66.70%). The primer SBS-Q3 exhibited the highest polymorphism of 66.70%. In case of ISSR primers, all primers recorded polymorphism (33.30-60.00%). The primer UBC866 was the most polymorphic primer with 60.0% polymorphism. RAPD and ISSR markers were compared for their efficacy in assessing the genetic diversity by taking the band frequency, Shannon's index, polymorphic information content, resolving power, and mean resolving power into consideration, and it was concluded that ISSR was marker of choice over RAPD.

The online version contains supplementary material available at 10.1007/s13205-023-03872-w.