Occurrence of Melampsora gelmii on Euphorbia dendroides: Morphological and molecular observations

Abstract

A rust fungus attack was observed on Tree Spurge (Euphorbia dendroides) in two regions of southern Italy. Uredinia and telia of a Melampsora species were detected on the leaves, bracts of the cyathia and capsules of E. dendroides. On the basis of the morphological characteristics and rDNA ITS sequences of the above mentioned structures, the fungus was identified as M. gelmii. This report suggests that M. gelmii seems to be a specific taxon in the M. euphorbiae complex and to be more widespread than previously detected in Italy. Further investigations within the M. euphorbiae complex would be desirable in order to elucidate the identity of M. gelmii as a peculiar form of a still poorly explored species.

Keywords:

• Pucciniales
• taxonomic recognition
• life cycle
• plant disease
• southern Italy

Acknowledgments

The authors are grateful to Senior Prof. Francesco Macchia for advice during slides observations, and to Antonio Biagio De Giuseppe and Nicodemo Giuseppe Passalacqua from the “Museo di Storia Naturale della Calabria ed Orto Botanico”, the University of Calabria, Italy, for providing precious indications about the Euphorbia species planted in the botanical garden. We would also like to thank Prof. Alessandro Ragazzi from the University of Florence for his very precious comments preceding the final version of the manuscript.