Association ofCandidatusphytoplasma asteris with little leaf and phyllody disease ofCatharanthus roseusin Eastern Uttar Pradesh, India

Abstract

During survey in 2006–2007 seasons at Gorakhpur, Eastern U.P., Catharanthus plants showed typical extensive chlorosis, proliferation of axillary shoots, bushy growing habit, small leaves, phyllody and stunting of the entire plants. DNA from phytoplasma symptomatic infected plants was extracted and amplification of phytoplasmal ribosomal DNA (rDNA) was done with the universal phytoplasma primer pairs P1/P6 and R16F2n/R16R2. All the five symptomatic Catharanthus plants examined tested phytoplasma positive in PCR and nested PCR assays in which a 1.5 kb and 1.2 kb fragment was consistently amplified from all the infected samples. Neither by direct (‘one-round’) nor by nested PCR assays was DNA amplified from template DNA isolated from any of the healthy non-symptomatic samples. The 1.2 kb amplicon obtained from nested PCR was cloned, sequenced and partial sequence were deposited in GenBank with Accession Number: EU694019. BLAST search analysis of EU694109 revealed 99% sequence similarity of 16Sr RNA gene sequence of the Catharanthus phytoplasma in the present study with those of phytoplasma members of 16SrI group, ‘Candidatus Phytoplasma asteris’ associated with Aster phytoplasma (AY265209, AF322645), Scaphytopius phytoplasma (AY180952, AY180943), Nasturtium phytoplasma (AY665676), Periwinkle phytoplasma (EU727085) and Parthenium phytoplasma (EU375485, EU375488).Therefore, the C. roseus phytoplasma in the present study was identified as an isolate of 16SrI group.