Canker and dieback on Platanus x acerifolia caused by Diaporthe scabra

Abstract

Summary Cankers and dieback on London plane caused by Diaporthe scabra have been observed in urban plantings in Catania, Italy. Symptoms were delayed spring flush, trunk cankers, small chlorotic leaves associated with dead terminal or lateral branches and an early defoliation. Isolations from infected wood on PDA led to the isolation of the anamorph Phomopsis scabra with α‐conidia production. The infected wood placed in a moist chamber developed pycnidia with α and β conidia and perithecia of the teleomorph D. scabra. Sequence analysis of the internal transcribed spacers ITS1 and ITS2, the ribosomal intragenic spacer beta‐tubulin 1 and beta‐tubulin 2 genes, congruently indicated that the D. scabra isolate is phylogenetically related to two strains of D. helianthi isolated in Italy from sunflower and to strains of D. eres. Inoculations on young plants of London plane growing in pots confirmed the pathogenicity of the isolated fungus. To our knowledge, this is the first report of the disease in Italy.

Characterisation and pathogenicity of fungal species associated with branch cankers and stem-end rot of avocado in Italy

“…Considering that several Diaporthe spp. are considered a threat to tropical and woody plant cropping in Sicily (Grasso et al 2012;Lombard et al 2014), confirmation of the identity and pathogenicity of these particular species was a valuable component of this study. Seven and six isolates were identified as D. foeniculacea and D. sterilis, respectively.…”

“…Thus, the number of avocado plantations has increased in eastern Sicily during the last 5-7 years. Unfortunately, in most avocado producing areas branch cankers and fruit stem-end rot are major on different woody hosts including avocado (UrbezTorres et al 2006;Adesemoye and Eskalen 2011;Grasso et al 2012). On avocado, canker symptoms can appear on shoots, branches or trunks (McDonald and Eskalen 2011).…”

Evaluating multi-locus phylogenies for species boundaries determination in the genusDiaporthe

“…The sequences more frequently used for these studies are: large subunit (LSU) of the ribosomal DNA, intergenic spacers (IGS) of the ribosomal DNA, internal transcribed spacer (ITS) of the ribosomal DNA, translation elongation factor 1-α ( TEF1 ) gene, ß-tubulin ( TUB ) gene, histone ( HIS ) gene, calmodulin ( CAL ) gene, actin ( ACT ) gene, DNA-lyase ( APN2 ) gene, 60s ribosomal protein L37 (FG1093) gene and mating type genes (MAT-1-1-1 and MAT-1-2-1) (Farr, Castlebury & Rossman, 2002; Farr, Castlebury & Rossman, 2002; Castlebury et al, 2003; Pecchia, Mercatelli & Vannacci, 2004; Schilder et al, 2005; Van Rensburg et al, 2006; Kanematsu, Adachi & Ito, 2007; Santos, Correia & Phillips, 2010; Santos et al, 2011; Thompson et al, 2011; Grasso et al, 2012; Sun et al, 2012; Udayanga et al, 2012; Baumgartner et al, 2013; Bienapfl & Balci, 2013; Gomes et al, 2013; Huang et al, 2013; Sun et al, 2013; Tan et al, 2013; Vidić et al, 2013; Gao et al, 2014; Udayanga et al, 2014a; Udayanga et al, 2014b; Wang et al, 2014). …”

A diverse range of Phytophthora species are associated with dying urban trees

“…Trees already predisposed to premature decline are susceptible to other factors that may incite or trigger a decline in health. These inciting factors can be diverse and include abiotic factors such as water stress, heat stress, or airborne pollution (Wang et al, 2011), or biotic factors such as pests (Aukema et al, 2011;Raupp et al, 2006) and diseases (Grasso et al, 2012;Jacobi et al, 2013;Minorsky, 2003;Yulia, 2011).…”