Rapid detection of sugarcane phytoplasma by PCR amplification using specific primers.

A part of conserved sequence of 16SrRNA gene of sugarcane phytoplasma in Sri Lanka (SP-SL) was analyzed to design polymerase chain reaction (PCR) primers for the detection of SP-SL in plant tissues. Newly developed sugarcane phytoplasma specific eighteen mer primers SPP1/SPP2 were used to a mplify 321 bp long rDNA sequence of SP-SL and the DNA fragment was visualized on agarose gel for the determination of presence of SP-SL in the substrate. Phytoplasmas associated with several symptomatic plants, both graminaceous and non-graminaceous, found in the SP-SL affected sugarcane fields were differentiated from SP-SL with the use of universal primer pair P1/ P2 followed by amplifying with the new specific primers. The amplification of SP-SL DNA was possible even at very low concentrations of templat e DNA such as about 0.04 ng in 20 µl of reaction mixture. This direct PCR method using new SPP1/ SPP2 primers is very specific, sensitive and rapid in the detection of SP-SL in plants.