First report on molecular characterization of Indian canna rust caused by Puccinia cannacearum

Abstract

Canna (Canna indica L.) a popular landscape ornamental and hardy plant prone to be affected by few fungal and viral diseases. However, in Karnataka the rust disease of canna caused by Puccinia cannacearum is noticed earliest at College of Horticulture, Bengaluru, Karnataka during the year 2016-17 and this is first attempt to characterize this rust pathogen from India. Symptoms of canna rust include: Initially, numerous orange-yellowish rusty spots on the lower surface of the leaves and on leaf sheath which turns brown and later covers the entire leaf area with coalescing pustules, eventually leads to premature senescence and severely infected leaves wither away. Microscopic examination of these rust pustules revealed the presence of golden pale yellow colored egg to pear-shaped uredospore (28-55 x 20-35 mm) with bristly walls and cylindrical to club-shaped teliospores (50-83 x 14-21 mm). Further, the pathogen was amplified and confirmed using ITS-rDNA primers with an amplicon size of 700 bp and phylogenetic analysis of the data revealed that the Indian isolate used under the study was found to be matched with China isolate (Accession no. JQ303103.1) of about 80% identity and the Indian isolate sequence was deposited in Gen Bank (Accession no.MH654794).