Microbial diversity in leaves, trunk and rhizosphere of coconut palms (Cocos nucifera L.) associated with the coconut lethal yellowing phytoplasma in Grand-Lahou, Cte dIvoire

The diversity of culturable bacterial and fungal communities was assessed from leaves, trunk and rhizosphere of coconut palms infected and non-infected by the Cote d’Ivoire lethal yellowing (CILY) phytoplasma. Bacterial and fungal microbes were isolated from leaves, trunk and rhizosphere samples collected from two villages of Grand-Lahou, Braffedon and Yaokro, by using a high-throughput 'dilution-to-extinction' cultivation method coupled with PCR and sequencing with primers that amplified both the 16S ribosomal RNA and intergenic transcribed spacer (ITS) genes. The relative abundance was higher for Bacillus and Candida in Braffedon, and Burkholderia and Neodeightonia in Yaokro. Commonly genera identified from rhizosphere included Bacillus, Burkholderia, Pseudomonas, Streptomyces, Cryptococcus, Penicillium, Purpureocillium and Trichoderma. The most abundant endophytes identified were Pantoea, Candida, Cryptococcus, Bacillus, Pseudomonas, Penicillium, Aspergillus and Rhodotorula. Genera limited to symptomless palms included Arthrininum, Chaetomium, Phialemonium, Fusarium, Klebsiella and Candida. Results indicate that the CILY phytoplasma may be a factor determining the level of diversity of a microbial community in a given location. Our research provides the basis to investigate the possible effect of endophytic and rhizosphere microbes against the CILY phytoplasma to further effectively improve the management of CILY in Grand-Lahou. Key words: Cote d’Ivoire lethal yellowing phytoplasma, endophytes, biocontrol, coconut.