Abstract
Highbush blueberry is an increasingly important crop due to its economic value and demonstrated health benefits of blueberries. Leaf spots are considered as minor diseases of blueberry plants, but they adversely affect blueberry productivity, causing reduced photosynthetic activity, flower bud formation and berry production. Surveys of blueberry crops were conducted in Piedmont, Northern Italy, during 2019-2020. Fungi isolated from leaf spots of the blueberry cultivar ‘Blue Ribbon’ were identified as Colletotrichum helleniense through a robust multi-locus phylogeny. Eight genomic loci were considered: tub, gapdh, act, cal, his3, chs-1, ApMat and gs. Morphological characters of a representative strain were assessed. Pathogenicity was confirmed on four blueberry cultivars, although with different levels of aggressiveness to the cultivars. This study shows the importance of a polyphasic approach to investigate species of Colletotrichum, and the relevance of molecular tools for the species-level characterization within the ‘Kahawae’ clade. This is the first report of Colletotrichum helleniense causing leaf anthracnose on Vaccinium corymbosum.
Highlights
Highbush blueberry (Vaccinium corymbosum, Ericaceae) is an increasingly important crop in Italy, with Piedmont, Veneto and Trentino Alto Adige as the major production areas (Brazelton, 2011)
Leaf spots are considered as minor diseases of blueberry plants, but they adversely affect blueberry productivity, causing reduced photosynthetic activity, flower bud formation and berry production
Fungi isolated from leaf spots of the blueberry cultivar ‘Blue Ribbon’ were identified as Colletotrichum helleniense through a robust multi-locus phylogeny
Summary
Highbush blueberry (Vaccinium corymbosum, Ericaceae) is an increasingly important crop in Italy, with Piedmont, Veneto and Trentino Alto Adige as the major production areas (Brazelton, 2011). Previous studies based on morphological features ascribed the species causing blueberry anthracnose mainly to the Colletotrichum acutatum species complex (SC), (C. acutatum sensu stricto, C. fioriniae, C. nymphaeae), C. gloeosporioides SC (C. fructicola, C. gloeosporioides sensu stricto, C. kahawae, C. siamense), C. boninense SC (C. karstii) and C. orchidearum SC (C. sichuaninese) (Hartung et al, 1981; Barrau et al, 2001; Kim et al, 2009; Xu et al, 2013; Rios et al, 2015; Pszczolkowska et al, 2016; Ali et al, 2019; Liu et al 2020). Rios et al (2015) reported Colletotrichum karstii in association with blueberry leaf spots in Brazil Since these species could persist as sources of inoculum in the field, affecting orchards and possibly cross-infecting other nearby crops while switching to a pathogenic lifestyles, specific pathogen identification should be provided (Fuentes-Aragón et al, 2020). Molecular data are combined with morphological characters and pathogenicity tests in a polyphasic approach to clearly identify species within the Colletotrichum SC (Guarnaccia et al, 2019, 2021a; Damm et al, 2019)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
