Molecular Detection and Characterization of Little Leaf Disease in Brinjal

Abstract

A nested Polymerase Chain Reaction (PCR) was optimised to detect the phytoplasma pathogen of brinjal showing little leaf symptoms. The second round primers amplicon was then cloned with pGEMT vector and fully sequenced. A 1200 bp DNA fragment encoding the portion from 16S rRNA gene of brinjal phytoplasma consistently amplified by universal primers and 890 bp from second round specific primers. The amplicon was cloned and sequenced. Nucleotide analyses of the fragment (GQ184436) showed that the gene was closely related to members of candidatus phytoplasma. The sequence identity similarity with members of the clover proliferation group (16Sr VI) was >99%, while the sequence identity with members of other groups (16Sr VI Elm yellows group) showed 97-98 % similarity. On the basis of sequence identity and phylogenetic relationship studies, it was concluded that the phytoplasma infecting brinjal in Tamil Nadu, India belonged to the clover proliferation group.