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Phaeoacremonium spp. 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 of Phaeoacremonium spp. 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 aleophilum and Phaeoacremonium iranianum were identified from apple trees and P. aleophilum was recovered from apricot trees with trunk disease symptoms. A phylogenetic analysis based on the sequence data from β-tubulin gene further confirmed the identity of the species as P. aleophilum and P. iranianum. The results of inoculation assay on detached shoots of apples revealed that P. iranianum is pathogenic on apple. Our results also showed that P. aleophilum isolates 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 the P. aleophilum isolates. This study is the first report on the occurrence of P. iranianum on apple trees with trunk disease symptoms worldwide and the first report on the occurrence of P. aleophilum on apple and apricot in Iran.

Sunflower leaf spot is one of the most common as well as important foliar diseases of this host in northern Iran. Stemphylium vesicarium was revealed to be one of the causal agents of sunflower leaf spot based on morphological and molecular characteristics. The identity of the species was confirmed using sequence data from the ITS rDNA region and glyceraldehyde-3-phosphate dehydrogenase (gpd) gene sequences. Pathogenicity of the fungus was proven by inoculation of four-week-old sunflower plants (cv. Euroflor) under controlled conditions. This is the first report on the incidence of S. vesicarium on H. annuus anywhere in the world.

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Leaf spot disease of sunflower is one of the most important foliar diseases on this crop worldwide. Several fungal groups are known to cause leaf spot disease on sunflower. Species of the genus Alternaria are the most common and serious leaf spot causing fungi on this crop. Leaf spot disease is the most destructive foliar diseases on sunflower in northern Iran; however, the identity of the causal agent remains unknown. The present study was aimed to characterise the identity of the causal agent of the disease by means of morphological and molecular data as well as to evaluate the pathogenicity of the responsible species. For this purpose, a total number of 97 fungal isolates were recovered from sunflower leaves with leaf spot disease symptoms from the sunflower fields in northwestern zone of Iran. All of the isolates were identified as Alternaria alternata based on cultural and morphological characteristics. A subset of isolates was subjected to phylogenetic analysis using sequence data from ITS-rDNA region, gpd and rpb2 genes. Sequence data from ITS-rDNA and gpd did not discriminate A. alternata from the other small-spored Alternaria species. A phylogeny inferred using sequence data from rpb2 gene clustered our isolates in several sub-clades within a single monophyletic clade. Sequence data for the type strain of the other small-spored Alternaria species has to be included in phylogenetic analysis, in order to make sure, whether the observed variations in rpb2 gene sequences are an indication for the population variation in sunflower isolates of A. alternata or define species boundaries among the small-spored Alternaria species. The results of pathogenicity assay on sunflower plants (cultivar Euroflor) under greenhouse condition revealed that A. alternata is pathogenic on sunflower.