Leaf anthracnose and defoliation of blueberry caused by Colletotrichum helleniense in Northern Italy

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.

Shoot Dieback in Thornless Blackberries in Northern Spain Caused by Diaporthe rudis and Gnomoniopsis idaeicola

“…In contrast, it was more complex when construct-ing the phylogenetic trees. Despite the fact that Guarnaccia et al [34] used only three genes (ITS, tub2, and tef-1a), other authors used up to five loci in previous papers [15,[35][36][37][38]. Santos et al [39] proposed that tef-1a was a superior phylogenetic marker in Diaporthe compared to ITS, while Gomes et al [15] considered tub2 and his to have higher resolutions than tef-1a and cal.…”

“…D. rudis, a synonym for D. viticola [27], has been described as a pathogen in hosts of high agro-economic value, for instance, associated with the stem blight and dieback of blueberries in northern Italy [34], avocados in Chile [45], and Pyrus communis in the USA [46]. In addition, it is also associated with other Diaporthe species causes kiwifruit rot during cold storage in Chile [47] and soybean seed decay in Serbia [48].…”

First report of Peroneutypa scoparia associated with canker disease on Ficus carica in northern Iran

“…Peroneutypa scoparia is associated with canker, stem blight and dieback symptoms on blueberry in northern Italy (Guarnaccia et al., 2020) and on grapevine in California (Úrbez‐Torres et al., 2020). Closely related taxa such as Eutypella species (e.g., E .…”

Two new species of Diaporthe (Diaporthaceae, Diaporthales) in China

“…As plant pathogens, Diaporthe spp. cause severe diseases, e.g., blights, cankers, decay, dieback, leaf spots and wilt of many economically important plants in genera Castanea , Citrus , Helianthus , Macadamia , Rosa , Vaccinium and Vitis , resulting in major losses ( Thompson et al 2011 ; Huang et al 2015 ; Guarnaccia et al 2018 , 2020 ; Hilário et al 2020 ; Wrona et al 2020 ; Caio et al 2021 ; Jiang et al 2021a ).…”