Molecular characterization of temple tree rust caused by Coleosporium plumeriae Pat.

Temple tree (Plumeria rubra) is a cosmopolitan ornamental flowering and an avenue tree. Generally, Plumeria sp. is affected by several diseases, among them rust caused by Coleosporium plumeriae was found infecting the temple trees in Bengaluru, Karnataka, India with the severity of 80-100 per cent in the early June till end of August 2016-17. Initially, numerous orange coloured rusty pustules were seen on abaxial leaf and these pustules covered the entire leaf causing inward rolling of leaves, necrosis, senescence and finally leaf abscission. Microscopic observation of the rust pustules revealed the presence of golden pale yellow coloured uredospores that varied from globose to ellipsoidal in shape, ranging from 20-40 x 16-28 mm in size, borne on erumpent uredinia and no other spore stages were observed. Molecular identification of this pathogen (Indian isolate) through ITS rDNA region amplification, sequencing and phylogenetic analysis revealed 99 % sequence homology with the China isolate (Accession no. KF879087.1). ITS rDNA region partial sequence of the pathogen was deposited in NCBI, GenBank with accession no. MH656772.