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Phytoplasma is an intracellular, pleomorphic, gram positive bacteria with lack o f cell wall
and important for plant disease in hundreds of economic plant species in Sri Lanka.
Several symptoms such as witches' broom, phyllody, virescence, bolting, formation o f
bunchy fibrous secondary roots, yellowing/ reddening, stunting and phloem necrosis have
been observed in cultivated crop commodities as w ell as weeds which collected from
different areas in Sri Lanka. Addition to that, seed samples were collected and let them to
germinate in inside the laboratory to detect seed bone transmission o f phytoplasma. DNA
was extracted by using Phenol extraction method for direct Polymerase Chain Reaction
(PCR). Symptomatic and asymptomatic plants were detected for phytoplasma through the
amplification o f a typical genomic fragment o f 557 bp by using universal primer P I/ P7.
Out of 250 plants 110 gave positive results since Nested PCR technique was practiced for
further confirmation. Samples which gave positive results were confirmed Nested PCR,
for 1st PCR round R16mF2/ R16Mrl primers were used and amplification size was 1.4
kb. Second PCR 1.2 kb fragment was taken by using R16F2n/ R16R2 primers. 31
samples were subjected to gene sequenced. Through Nested PCR out o f 110 samples 28
samples were gave positive results and they were confirmed as phytoplasma and they
were submitted to similarity search ( BLAST ) in the NCBI database which confirmed
that a phytoplasma belonging to the 16Sr “ Candidates Phytoplasma” group.
Phylogenetic tree was performed by using sequenced phytoplasma samples 28 positive
included samples symptomatic samples and asyptomatic plant samples. 10 samples were
observed as seed bone transmission o f phytoplasma
