• The Plant Pathology Journal
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• v.27 no.2
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• pp.120-127
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• 2011

While many isolates of Alternaria alternata are common saprophytes on trees and shrubs, this study clearly demonstrated that A. alternata is a primary pathogen in lilac (Syringa sp.), causing a leaf-blight that affects different Syringa species. Isolates of Alternaria sp. were collected from leaf blight samples of lilacs in the field. The internal transcribed spacer (ITS) region and morphological characterization were used to identify lilac blight pathogen. Based on 100% ITS nucleotide sequence identities to the Alternaria genus in the GenBank and morphological features, these isolates were identified as A. alternata. Disease symptoms were reproduced in lilac plants inoculated with A. alternata mycelial plugs and sprayed with a fungus-free culture filtrate, indicating that pathogenesis in lilac involves secondary metabolites or toxins. Diagnostic primers were developed to detect Alternaria sp. and A. alternata in lilac leaf blight based on ITS region and four known genes associated with pathogenesis in A. alternata: mixed-linked glucanase precursor, endopolygalacturonase, hsp70, and histone genes. The results from our study indicated A. alternata is a primary pathogen in lilac leaf blight, and these diagnostic primers can be used as a tool for the fast detection of A. alternata associated with lilac leaf blight.

• Korean Journal Plant Pathology
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• v.11 no.1
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• pp.1-8
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• 1995

Alternaria alternata and A. solani were identified from 130 Alternaria isolates obtained from red pepper fruits, and three species including A. alternata, A. sesami and A. sesamicola were detected from 150 isolates from sesame seeds. Among the 4 Alternaria species, A. alternata was the predominant fungus from both plants, having incidence of 95.4% in red pepper and 56.0% in sesame. Of the total 280 isolates, cultures on autoclaved rice of 75 isolates were tested for toxicity to 21-day-old virgin female rats. Out of 50 isolates of A. alternata, 17 were lethal to rats, inducing congestion and hemorrhage of stomach and intestine and kidney enlargement, and 8 caused lack of weight gain or weight loss. The other 25 isolates of A. alternat and all the isolates of A. sesami, A. sesamicola and A. solani, showed no significant indication of toxicity. Production of mycotoxins in the rice cultures of the above 75 isolates belonging to 4 species was analyzed. Alternaria cultures were extracted with methanol and purified by using solvent partition, thin-layer chromatography, and high performance liquid chromatography. Of the four species tested, all produced alternariol (AOH) and alternariol monomethyl ether (AME), three (A. alternata, A. sesami and A. sesamicola) produced alternuene (ALT) and altertoxin-I (ATX-I), and only A. alternata produced tenuazonic acid (TA). TA was produced by all of the highly toxic (lethal to rats) isolates of A. alternata, but not by any nontoxic isolates.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.66-71
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• 1996

79종의 식물재료의 Alternaria alternata에 대한 항균활성을 조사한 결과, 7가지 식물재료가 항균활성이 있었고, 11가지는 확실치 않았으며, 나머지 61가지는 항균활성이 나타나지 않았다. A. alternata에 항균활성이 나타난 7가지 식물재료 중 계피가 활성이 가장 높았으며, 오미지와 천궁이 중정도의 활성을 보였으며, 나머지는 약한 활성을 나타내었다. 항균 활성 성분은 계피와 천궁의 경우는 diethyl ether에 분리되었고, 오미자의 경우는 butanol에 분리되었다. 계피의 diethyl ether 추출물은 1,000 배액 이하에서 식별 가능한 항균활성이 나타났다. 계피의 성분으로 cinnam aldehyde가 가장 높은 활성을 보여, 이 물질이 계피의 주요 항균물질로 사료된다.

• The Korean Journal of Mycology
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• v.48 no.4
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• pp.369-379
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• 2020

Black mold was frequently observed on tomatoes grown in a greenhouse in Suwon, Korea in July 2018. The incidence of the disease was 5.0-25.0% (average 12.3%) and 2.0-7.0% (average 3.7%) in the context of tomato and cherry tomato fruits, respectively. Sixteen single-spore isolates of Alternaria sp. were obtained from the diseased fruits and investigated for their morphological characteristics. Among the isolates, eight were used for sequencing analysis. All of the isolates were identified as Alternaria alternata based on their morphological and molecular characteristics. The pathogenicity of four isolates of A. alternata was investigated using three varieties each of tomato and cherry tomato via artificial inoculation. All of the isolates induced black mold symptoms on the inoculated tomato fruits. Notably, the symptoms were similar to those observed in the greenhouse. However, the pathogenicity tests revealed that different tomato varieties presented distinct patterns of susceptibility to the isolates. This is the first report of A. alternata causing black mold on tomato fruits in Korea.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.226-229
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• 2016

The growth of two different fungal species, human pathogenic Cryptococcus neoformans and plant pathogenic Alternaria alternata were inhibited by a chitinase (Chi2) expressed in the autolysing tissue of Coprinellus congregatus. The cell wall thickness was reduced (up to 32%) in C. neoformans compared with that of normal cell, and polysaccharide fibers located outside of the cell wall were also severely removed. The hyphal growth of A. alternata on agar plate was stopped by the enzyme. The allergic inflammation induced by A. alternata was reduced by the enzyme reaction when compared with untreated control in a mouse model.

• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.67-71
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• 1985

A severe infection on pepper fruits by a black mold fungus was observed in the fields, Suweon. Conidia of Alternaria sp. were isolated from the infected fruits. Based on the morphological characters and size of the conidia, the fungus was identified as Alrernaria alternata (Fries) Keissler. The single spore isolates of A. alternata were weakly or not pathogenic on non-wounded pepper fruits, but highly virulent on fruits wounded with sandpaper or heated-glass rod. The infection on the wounded fruits were more severe on red fruits than on immature green ones. No visible infection was found on leaves and stems when 60-day-old plants of pepper were inoculated with the fungus. In July of 1984, the field losses of pepper fruits caused by black mold were $2.0\~22.5\%$ in Suweon.

• Korean Journal Plant Pathology
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• v.14 no.1
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• pp.92-98
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• 1998

RAPD analysis was performed from four host-specific toxin (HST) producing Alternaria, i.e., A. kikuchiana, A. mali, a. longipes and A. Longipes and A. alternata f. sp. lycopersici, nonpathogenic A. alternata and A. brassicicola to assess their phylogenetic relationship. DNA polymorphism was detected among species (pathotypes) of HST producing Alternaria by PCR amplification and differentiation of the species was recognized by RAPD analysis. Primer OPA-02 was the most profitable among 7 notificated primers for differentiation of the HST producing Alternaria species. UPGMA analysis of the RAPD bands from alternaria spp. revealed that HST producing Alternaria and nonpathogenic a. alternata are closely related.

• Journal of Mushroom
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• v.21 no.4
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• pp.195-199
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• 2023

The fungus Alternaria alternata, responsible for causing brown to black spotting on numerous fruits and vegetables globally, was identified in 2022 as the causative pathogen of brown spot disease in potatoes in Korea. In pursuing potential inhibitors against A. alternata growth, we evaluated 15 mushroom culture filtrates: eight from Trametes spp. and seven from Polyporus spp., known for their antibacterial and anticancer properties. Antifungal activity was assessed by exposing each filtrate to A. alternata on a paper disc. Four filtrates displayed inhibitory action against the fungus, albeit with mild effects. Our findings highlight the potential of Trametes and Polyporus fungi as emerging antifungal candidates, offering promise in preventing potato brown spots.

• The Plant Pathology Journal
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• v.18 no.4
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• pp.210-215
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• 2002

Four field experiments were carried out from 1998 to 1999 and from 1999 to 2000 growing seasons of potato to investigate the relationship between leafminers and Alternaria alternata. The experiments established differential susceptibility among potato varieties to alternaria leaf necrosis, relationship between leafminer infestation and the level of necrosis, use of insecticides to reduce leafminer and leaf necrosis damages, and use of polyester fleece to eliminate leafminer and eventually reduce leaf necrosis. Results of the study indicate that control of leafminer is of primary importance because this will automatically lead to control of the damage caused by A. alternata.

• Mycobiology
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• v.41 no.3
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• pp.167-169
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• 2013

Black spot of sweet persimmon, caused by Alternaria alternata, occurred in an orchard in Gyeongnam province, Korea in 2012. The symptom was appearance of 0.5 to 4 cm black spots on the surface of fruit. The pathogen was isolated from flesh of disease lesions. The causal agent was identified as A. alternata by morphological characteristics and sequencers of the internal transcribed spacer (ITS) 1 and ITS4 regions of rRNA. Artificial inoculation of the pathogen resulted in development of disease symptoms and the re-isolated pathogen showed characteristics of A. alternata.