Molecular identification of ‘Candidatus Phytoplasma oryzae’ in Garcinia gummi-gutta in India

Garcinia gummi-gutta is a medicinal plant growing in Asia and Africa. During a survey in 2017, witches’ broom and little leaf symptoms were observed on G. gummi-gutta (GaLL&WB) plants at Kumarakom Kottayam district of Kerala, India. The disease incidence recorded was 2%. An investigation was carried out to identify the phytoplasma associated with the GaLL-WB. Amplicons of ∼1.25 kb were consistently amplified from DNA extracted from all the GaLL-WB affected plants in a nested PCR assays using primer pairs P1/P7 and R16F2n/R16R2, however, no amplification was observed with any of the symptomless plant samples. The 16S rDNA sequence of the GaLL&WB phytoplasma revealed 98.2% of sequence identity to those of ‘Candidatus Phytoplasma oryzae’ strains and computer simulated RFLP analysis of the GaLL-WB 16S rDNA sequence confirmed it as a member of the group 16SrXI, subgroup B. This is the first report of ‘Ca. P. oryzae ’associated with little leaf and witches’ broom disease of G. gummi-gutta.