Identification and genetic relationship among phytoplasma strains infecting coconut, arecanut and oil palm in South India

A survey was carried out for spear rot disease (SRD) of oil palm, yellow leaf disease (YLD) of arecanut and root (wilt) disease (RWD) of coconut in Kerala and Karnataka. The 16Sr RNA gene sequence comparison, phylogenetic analysis and in silico RFLP analysis of SRD, YLD and RWD phytoplasma isolates revealed the association of 16SrXI-B subgroup phytoplasma in Kerala and 16SrXIV-A sub-group in Karnataka in oil palm, arecanut and coconut and possible cross transmission among all the three palm species in Kerala and Karnataka. However, detection of 16SrXIV group phytoplasma was also found with RWD in a severely affected area of Kerala. Possible involvement of more than one group/sub-group of phytoplasmas with these three palm diseases in different locations was indicated, which warrants further investigations on epidemiology and genetic variation in phytoplasmas at different locations to adopt appropriate management strategy.