Revision of Ganoderma species associated with stem rot of coconut palm

ABSTRACT

Stem rot by Ganoderma is a disease of major concern for coconut farmers. Many species (G. applanatum, G. boninense, G. lucidum, G. zonatum) have been implicated as the causal agents of the disease. Despite its importance, systematics of the rot-associated Ganoderma remains uncertain and unresolved. Morphologically heterogeneous basidiomata of the putative pathogen(s) from infected palms in multiple disease sites were collected during an outbreak in the coastal state of India, Kerala. Morphological and molecular investigations revealed that these specimens were distinct from all the Ganoderma species so far identified and reported from coconut. Although with a close morphological resemblance to many Ganoderma species collected from palms, they exhibited unique genetics and geographic distribution patterns. We present a taxonomic reassessment of the species collected from infected coconut palms in India and also propose two new species, Ganoderma keralense and G. pseudoapplanatum. A taxonomic key to Ganoderma species on palms is given.

KEYWORDS:

• Basidiomycota
• multilocus study
• Polyporales
• phylogeny
• systematics
• 2 new taxa

ACKNOWLEDGMENTS

The authors thank the Chief Conservator of Forests & Chief Wildlife Warden, Kerala, for permission for field work in the forest areas of Kerala. The authors are grateful to all the anonymous reviewers for their critical comments and suggestions, which helped improve the manuscript.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

Additional information

Funding

N. Vinjusha acknowledges support from the Kerala State Council for Science, Technology and Environment (KSCSTE) in the form a PhD fellowship.