A blight disease on highbush blueberry associated withMacrophomina phaseolinain Serbia

Abstract

Unusual blight-like symptoms appeared on highbush blueberry plants in Serbia during August 2015 and infected plants showed browning and reddening of leaves, drying of foliage, and brown discoloration of internal vascular stem tissues. The objective of this study was to isolate and confirm a causal agent of the disease. Five diseased blueberry plants (2-yr-old), with visible brown discoloration in the wood, were collected for isolation on potato dextrose agar (PDA). Morphological analysis of the selected fungal isolates showed the presence of abundant black, round to oblong, or irregularly-shaped microsclerotia immersed in the PDA. Dark, globose pycnidia formed on water agar with an initially hyaline, granular content and single-celled conidia, indicating the presence of plant pathogenic fungus Macrophomina phaseolina associated with symptomatic plant tissues. Pathogenicity was confirmed on potted blueberry plants based on the initial symptoms of leaves turning yellowish to brown at the leaf edges, followed by the defoliation of leaves of the inoculated stems. Discoloration of vascular tissues was also observed on transverse sections of inoculated stems. The pathogen M. phaseolina was confirmed using molecular analysis of the ITS1-5.8S-ITS2 region of rDNA and a part of the TEF-1α gene region. This is the first report of M. phaseolina causing a blight disease on highbush blueberry in Serbia. The study should help in elucidating disease symptomatology and provide the knowledge on the risk which this fungus could pose in blueberry production.

Macrophomina vaccinii sp. nov. causing blueberry stem blight in China

“…O’Neal) indicated that inoculation of Macrophominavaccinii were pathogenic on blueberry stems which causes the stem turn brown with necrotic lesions. Similar symptoms caused by M.phaseolina have been reported on blueberry in Serbia, resulting in foliage death, and brown discoloration of internal vascular tissues at the basal part of the bush (Popović et al 2018). The brown lesion caused by M.vaccinii and M.phaseolina on blueberries differs from the widely reported charcoal rot diseases caused by Macrophominaphaseolina and M.pseudophaseolina (Su et al 2001, Salik 2007, Yang et al 2005, Zhang et al 2011, Sarr et al 2014, Sun et al 2015).…”

“…Blueberries ( Vaccinium spp.) are popular fruits because of their health benefits health, such as enhancing brain memory and preventing heart disease (Shi and Liu 2009, Popović et al 2018). Blueberries have been commercially cultivated worldwide, particularly in the USA, Canada and a few European countries (Evans and Ballen 2014).…”

“…For instance, Botryosphaeriadothidea , Lasiodiplodiatheobromae , Neofusicoccumribis , and N.parvum caused stem blight of highbush or rabbiteyes blueberries in USA (Milholland 1972, Creswell and Milholland 1988, Smith 2004, Wright and Harmon 2009, 2010, Koike et al 2014). Macrophominaphaseolina (Tassi) Goid caused stem blight of highbush blueberries in Serbia (Popović et al 2018). Neofusicoccumparvum caused stem blight and dieback of highbush blueberries in Mexico (Boyzo-Marin et al 2016).…”

“…Macrophominaphaseolina is a soil- or seed-borne polyphagous pathogen, causing charcoal rot disease on about 500 plant species of more than 100 families throughout the world (Su et al 2001, Babu et al 2007, Sarr et al 2014). In Serbia, M.phaseolina was reported as a causal agent causing foliage death and brown discoloration of internal vascular stem tissues of highbush blueberry in 2015 (Popović et al 2018). So far, M.pseudophaseolina has been reported causing charcoal rot disease on six plant species, viz.…”

Potential of Trichoderma spp. and Pinus sylvestris Bark Extracts as Biocontrol Agents against Fungal Pathogens Residing in the Botryosphaeriales

“…These fungi are known as endophytes, latent pathogens, pathogens and saprophytes and they usually cause disease when their hosts are under stress [9]. In Serbia, Botryosphaeriales are important pathogens of woody and vascular plants causing die-back, cankers, leaf blights, shot hole disease, fruit and root rot [13][14][15][16][17][18]. The pathogenicity of Botryosphaeriales is of a particular importance in urban environments as city parks are mostly comprised of plants belonging to diverse taxonomic groups and these fungi can infect multiple hosts [19].…”