The occurrence of Alternaria species on cabbage in Iran

Abstract

In a study on Alternaria species, associated with cabbage black spot disease in Urmia, West Azerbaijan, Iran, cabbage fields were inspected during the growing seasons of 2012-2013 and leaves with suspected symptoms of Alternaria infection were collected. A total of 135 isolates with Alternaria characteristics were obtained from 10 main growing areas in this region and studied taxonomically. On the basis of morphological characteristics of the studied isolates, 8 species viz. Alternaria arbusti, A. brassicicola, A. destruens, A. infectoria, A. perangusta, A. tenuissima, A. turkisafria and A. vaccinii were identified. Alternaria tenuissima with 53 isolates, A. brassicicola with 38 isolates and A. destruens with 29 isolates had respectively the highest frequency among the identified species and distributed all over the studied area. A. arbusti and A. perangusta each with only one isolate had the lowest frequency. Results obtained from the pathogenicity tests showed that all the tested isolates from identified species were pathogenic on cabbage leaves, although there were statistically significant differences in virulence of the tested isolates. A. brassicicola isolates had the highest virulence and A. arbusti and A. vaccinii isolates had the lowest virulence. Isolates belonging to other species had moderate virulence. Except A. brassicicola which had been previously reported from cabbage in Iran, all other seven species are reported for the first time from cabbage as the causal agents of black spot disease. Also, A. arbusti, A. perangusta and A. vaccinii are reported as new species for Iran mycoflora.

Physiological Characterisation of Alternaria brassicicola causing Alternaria Leaf Spot in Cabbage

“…Then these leaf bits were washed thrice in sterile water and placed aseptically on the sterile petriplate which was poured with the sterilized potato dextrose agar (PDA) medium (Rahimloo and Ghosta, 2015). These plates were incubated at room temperature (27±4 0 C) for proper development of the pathogen.…”

Alternaria leaf spot of broccoli caused by Alternaria alternata in Bangladesh

“…Brassica seedlings are often infected by seedborne pathogens, especially by the serious pathogen Alternaria spp. in many countries (Kubota et al 2006;Rahimaloo & Ghosta 2015). This study, for the first time, isolated and characterised the pathogen of Alternaria leaf spot in broccoli in Bangladesh as A. alternata.…”

Multigene Phylogeny and Pathogenicity Trials Revealed Alternaria alternata as the Causal Agent of Black Spot Disease and Seedling Wilt of Pecan (Carya illinoinensis) in South Africa

“…The fungus morphologically showed profuse mycelial growth on the PDA, turning grey–brownish [ 37 , 67 ] in colour, consistent with Woudenberg et al [ 19 ], and spores resembling those of A. alternata . Morphology was not the main means of identification, as Alternaria isolates could differ morphologically due to the different cultivating conditions and the overlap in the spore sizes of some species [ 68 ]. Armitage et al [ 69 ] reported that the morphological characteristics used to delineate species in Alternaria sect.…”