The occurrence of orange leaf phytoplasmas in India has not
previously been reported. However, recently the occurrence of
phytoplasmas in the Cauvery Delta areas and other rice
growing areas were noticed for first time. An extensive survey
has been conducted in the Cauvery Delta, Lower Bhavani
project Delta, Parambikulam Aliyar Delta, Periyar Vaigai
Project Delta and Thamiraparani Delta zones. The plants
exhibited typical symptoms with orange yellow discoloured
leaves which were distributed sporadically in the field
(Fig. 1). The symptoms were suspected to be phytoplasma as
testing for Rice Tungro Disease (RTD) with PCR gave negative
results and the bacterial blight pathogen could not be isolated.
Subsequently we attempted to identify the causal agent by
using nested PCR using phytoplasma specific primers.