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Trunk disease is a major problem on grapevine in Zanjan province, causing serious decline, despite which its aetiology remains unknown. The purpose of this study was to investigate factors involved in grapevine decline in vineyards of Zanjan province. Samples were collected from twigs and branches of grapevines in the region between October and November 2018. Fungal isolates were identified based on morphological characteristics and ITS‐rDNA sequence data for selected isolates. The frequency and diversity of the fungal community recovered from grapevines in Darreh Sejin in Zanjan province were higher than in other regions. A total of 112 fungal isolates comprising 22 species were recovered. Phaeoacremonium minimum, Microsphaeropsis olivacea and Kalmusia variispora were identified as the dominant species in the region examined and could be considered the main trunk pathogens of grapevines in Zanjan region. In inoculation tests, M. olivacea was proved to be pathogenic on grapevine for the first time in this study. [ABSTRACT FROM AUTHOR]

Grapevines exhibiting general decline symptoms were observed in July 2012 in Arbatan, a region in Marand county, north-western Iran. Leaf necrosis symptoms were also observed in affected grapevines. Dark brown necrotic lesions and wood discoloration were observed in the vascular tissues of affected cordons. Fungal isolates, all with similar cultural and morphological features, were obtained from symptomatic tissues. Morphological characteristics indicated that the isolates were Macrophomina phaseolina. Sequence analysis of the elongation factor (EF-1α) gene from isolates confirmed this identification, with 100% similarity to the reference M. phaseolina sequences obtained from GenBank. Pathogenicity assays of two M. phaseolina isolates on 2-year-old potted vines (cv. 'Keshmeshi') demonstrated that M. phaseolina was pathogenic on grapevine. This study confirmed the association of M. phaseolina with grapevine decline symptoms, and represents the first report of this fungus associated with grapevine trunk diseases in Iran. [ABSTRACT FROM AUTHOR]

Trunk diseases are potential threats for the grapevine industry owing to the worldwide incidence and economic impact of the diseases. Several fungal groups are known to be involved in these diseases. In a survey on grapevine trunk diseases in northern Iran, Cytospora isolates were repeatedly recovered from vines showing decline symptoms. The symptoms appeared as pale brown to brown streaks in longitudinal cuts of shoots. The morphological and cultural characteristics of the isolates were in agreement with the description of Cytospora chrysosperma. Sequence data of the ITS-rDNA region was used to further confirm the identity of the species. Phylogenetic analysis based on the sequence data obtained in this study and the sequences from GenBank, confirmed the morphological identification. Our isolates were clustered together with C. chrysosperma isolates known from other woody host plant species. The pathogenicity assay on detached shoots of grapevines induced the same symptoms as was observed in field conditions. Although, C. chrysosperma is known from several woody hosts in Iran, the occurrence of this species on grapevines showing decline symptoms is new. The economic impact, distribution, and degree of involvement of C. chrysosperma in decline of vines in other regions of Iran remains to be studied. [ABSTRACT FROM AUTHOR]

Phaeoacremoniumspp. are known as the main Hyphomycetes associated with esca disease symptoms on grapevines worldwide. The role of other woody hosts in proximity of vineyards as a possible inoculum source for the causal agents of grapevine esca disease mainly remains unknown. The aim of this study was to investigate the occurrence ofPhaeoacremoniumspp. on pome and stone fruit with trunk diseases symptoms in northwestern parts of Iran. For this purpose, wood trees samples were collected from apple and apricot trees with trunk disease symptoms. Isolation was made using routine plant pathology methods. Based on the morphological and cultural characteristics,Phaeoacremonium aleophilumandPhaeoacremonium iranianumwere identified from apple trees andP. aleophilumwas recovered from apricot trees with trunk disease symptoms. A phylogenetic analysis based on the sequence data fromβ-tubulingene further confirmed the identity of the species asP. aleophilumandP. iranianum. The results of inoculation assay on detached shoots of apples revealed thatP. iranianumis pathogenic on apple. Our results also showed thatP. aleophilumisolates from different hosts (apple, apricot and grapevine) were pathogenic on apple and induced wood discolouration on apple stems. There was no significant difference on the length of lesions induced in relation to the origin of theP. aleophilumisolates. This study is the first report on the occurrence ofP. iranianumon apple trees with trunk disease symptoms worldwide and the first report on the occurrence ofP. aleophilumon apple and apricot in Iran. [ABSTRACT FROM PUBLISHER]

Esca is a very important and destructive disease of grapevine in many grapevine producing countries. Several groups of fungi have been reported from grapevines with esca disease symptoms; however,Phaeoacremoniumspecies are the main hyphomycete fungi involved in this disease. In recent years, esca disease symptoms with consequent decline disease have frequently been observed in vineyards of north-western Iran. Nevertheless, the involvement ofPhaeoacremoniumspp. with esca disease symptoms in this region remains unknown. During 2008–2010 growing seasons, wood samples were collected from vines showing typical esca disease symptoms such as interveinal leaf chlorosis with subsequent necrosis and various types of internal wood deterioration in north-western parts of Iran. A total of 44Phaeoacremonium-like hyphomycetes were recovered from sampled materials. Fungal isolates were subjected to tentative morphological identification and were further characterised by using sequenced data from ITS-rDNA and β-tublin gene. Phylogeny inferred using sequence data from ITS-rDNA region and β-tublin gene revealed thatPhaeoacremonium aleophilumandP. mortoniaetogether withSarocladium strictum(syn.Acremonium strictum) are associated with esca disease symptoms in this region. The pathogenicity ofPhaeoacremoniumspp. andSarocladium strictumwere verified by the inoculation of cutting root and stems under greenhouse conditions. Isolates ofP. aleophilumandP. mortoniaewere the most virulent based on the length of vascular necrosis on woody stems that followed bySarocladium strictum. This is first study on the pathogenicity ofSarocladium strictumon grapevine worldwide and the first report on the occurrence ofP. mortoniaeon grapevines in north-western Iran. [ABSTRACT FROM PUBLISHER]

During surveys on grapevines trunk diseases in vineyards at different localities in East and West Azerbaijan and Ardabil provinces, Iran, wood samples (two, three year-old cordons) were collected from grapevine showing decline symptoms, including leaf yellowing and necrosis, stunted growth, internal wood necrosis, black vascular discolouration. Nine fungal isolates with similar morphology were recovered from grapevines with decline symptoms in five different areas, which one-third of the isolates were recovered as the sole fungal agents. The identity of fungal isolates was determined as Quambalaria cyanescens based on the combination of cultural and morphological characteristics and DNA phylogeny. Pathogenicity trials based on excised shoot assay and potted grapevine under greenhouse conditions confirmed Q. cyanescens being pathogenic on grapevines; the isolates induced symptoms similar to those observed in naturally infected grapevines. Our findings confirm Q. cyanescens as a new fungal trunk pathogen of grapevine. Members of the genus Quambalaria are known to cause leaf spot, shoot blight and canker disease on Eucalyptus and its relative Corymbia. The current study is the first regarding pathogenicity of the Q. cyanescens on woody hosts; in previous studies Q. cyanescens has proven to be non-pathogenic to Corymbia spp. The host range, extent of geographical distribution and economic significance of this new pathogen on grapevine remains to be studied. Image 1 • Quambalaria cyanescens was recovered from grapevine with typical decline symptoms. • A polyphasic approach was employed to ascertain the identity of the causal agent. • Quambalaria cyanescens was confirmed to be pathogenic on grapevine. • We report Q. cyanescens as a new fungal trunk pathogen on grapevine, worldwide. • Pathogenicity of Q. cyanescens on woody hosts was confirmed for the first time. [ABSTRACT FROM AUTHOR]