First report of rust caused by Coleosporium campanulae on Campanula rapuncoloides in Italy

Creeping bellflower (Campanula rapunculoides) is a popular flowering plant commonly used in parks and gardens in northern Italy. In August 2016, plants of Campanula rapunculoides grown in a garden located near Biella showed leaf chlorosis followed by the appearance of orange pulverulent rust pustules irregularly distributed in the abaxial surface of leaves. Based on morphological characteristics, sequence analysis of the rDNA internal transcribed spacer region and pathogenicity test, the causal agent was identified as Coleosporium campanulae [Coleosporium tussilaginis f.sp. campanulae-trachelii]. Although Coleosporium campanulae is reported in several European countries on different spontaneous native plants including the campanula host genus, this is thought to be the first report of Coleosporium campanulae on cultivated Campanula rapunculoides in Italy.