Multiplex RT-PCR, a novel technique for the simultaneous detection of the DNA and RNA viruses causing rice tungro disease

Rice tungro, economically the most important viral disease of rice, is a complex disease caused by two morphologically and genomically dissimilar viruses, Rice tungro bacilliform virus (RTBV), a double stranded DNA virus replicating through RNA intermediate and Rice tungro spherical virus (RTSV), a single stranded RNA virus with 3' poly (A) tail. A novel multiplex RT-PCR technique for the simultaneous detection of RTBV and RTSV from the total RNA extracted from tungro-infected plants has been developed. It involves a one-step reaction initiating first strand cDNA synthesis by oligo (dT) primer with poly (A) tailed RTBV transcript and RTSV genomic RNA as template for the PCR amplification. The results indicate that adaptation of this technique will strengthen the screening for tungro resistance among rice varieties and hybrids.