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Basal stem rot caused by Ganoderma lucidum is the most serious disease in coconut and arecanut gardens. Twenty-five Ganoderma isolates were collected from different parts of India and the pathogenicity of Ganoderma was proved on coconut seedlings. Mature sporophores developed within 10-13 weeks after inoculation of pathogen under in vivo. To detect the pathogen at early stage, DNA-based technology, polymerase chain reaction was used. In this, the primers Gan1 and Gan2 produced a product of 167 bp in size for all the Ganoderma isolates tested. Simultaneously, ITS 1 and ITS 4 primers amplified a fragment of 680 bp in the Ganoderma isolates. In addition, Ganoderma isolates showed polymorphism in the random amplified polymorphic DNA analysis.

Groundnut (Arachis hypogaea L.) suffers from many soil borne pathogens that deteriorate the quality of the seeds and are responsible for high yield loss. Practically Trichoderma sp. is used for seed treatment, it minimizes the seed and soil borne pathogens and supports plant growth promotion activities. In the present study, five different isolates of Trichoderma spp. were isolated from groundnut (A. hypogaea ) rhizosphere soil. All the five isolates were confirmed by morphological methods and using molecular tools through Polymerase Chain Reaction (PCR) amplification of Internal Transcribed Spacer (ITS) region of Trichoderma sp. and DNA gets amplified in 650 bp to 700 bp. Trichoderma spp. were molecularly identified as T(SP)-20 (Trichoderma longibrachiatum), T(AR)-10 (T. asperellum), T(VT)-3 (T. hamatum), T(BI)-16 (T. longibrachiatum), T(TK)-23 (T. citrinoviride). Phytostimulation activities of all the six isolates viz., phosphate solubilization, Ammonia production, IAA production, and Siderophore production, were evaluated. Among the six isolates, T(SP)-20, T(AR)-10, and TNAU-TA showed higher phytostimulation activities. The growth promotion of Trichoderma spp. on groundnut was assessed through the roll towel method. The isolate T(SP)-20 (T. longibrachiatum) produced the highest germination percentage of 93.33 and vigor index of 2246.2. This work developed a new isolate of T. longibrachiatum (T(SP)-20) which is a native isolate having significant  phytostimulation and growth promotion activities and it could be exploited for other soil borne disease managing successfully.

Endophytic bacteria Bacillus subtilis (EPC 5) was isolated and tested in vitro along with Pseudomonas fluorescens (Pf1) and the fungus Trichoderma viride (Tv1) against Ganoderma lucidum (Leys) Karst, the causal agent of basal stem rot on coconut palm. The endophytic bacterial strains namely EPC 5 and EPC 8 showed higher vigor index (germination percentage, root and shoot length) and more inhibition against G. lucidum over un-inoculated control. These strains were confirmed as Bacillus subtilis by biochemical tests, cloning and sequencing of internal transcribed spacer (ITS) region. The Bacillus subtilis (EPC 5) along with Pseudomonas fluorescens (Pf1) and Trichoderma viride (Tv1) has been tried as bioconsortia against basal stem rot disease under greenhouse conditions. The soil application of bioconsortia enriched with farm yard manure (FYM) enhanced the coconut saplings growth under greenhouse conditions and showed higher induction of defense related enzymes like peroxidase, polyphenol oxidase, phenylalanine ammonia lyase and phenols when challenged with pathogen.

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