• The Plant Pathology Journal
• /
• v.19 no.5
• /
• pp.221-226
• /
• 2003

Twenty universal rice primers (URPs) were used to detect PCR polymorphisms in 25 isolates of six different Alternaria species producing host specific toxins (HST). Eight URPs could be used to reveal PCR polymorphisms of Alternaria isolates at the intra- and inter-species levels. Specific URP-PCR polymorphic bands that are different from those of the other Alternaria spp. were observed on A. gaisen and A. longipes isolates. Unweighted pair-group method with arithmetic mean (UPGMA) cluster analysis using 94 URP polymorphic bands revealed three clustered groups (A. gaisen group, A. mati complex group, and A. logipes group).

• Korean Journal of Agricultural Science
• /
• v.7 no.2
• /
• pp.77-80
• /
• 1980

Alternaria longissima Deighton & Macgarvie was recorded for the first time on seeds of sesame in low percentages. Detailed descriptions of the habit characters, conidial morphology and cultural characters are described. This fungus, which is generally regarded as a saprophyte, was shown to be a pathogen to sesame plants producing zonate leaf spots, foliage blight, stem necrosis and spots on capsules, but does not show any pathogenicity to rice and sorghum plants.

• Animal cells and systems
• /
• v.10 no.1
• /
• pp.21-25
• /
• 2006

In the present study, Dravya-an organic compound used for seed treatment along with the common fungicides to test its compatibility in the management of Alternaria padwickii in paddy. Dravya (a sea weed extract) was found highly compatible with fungicides like Bavistin and Dithane M-45. Incidence of Alternaria padwickii and Bipolaris oryzae was also reduced to a greater extent in the paddy seed samples of Dravya treatment. On the other hand, it also enhanced the seed germination and seedling vigour. Seedlings of treated samples also showed enhanced activity of peroxidase upon challenge inoculation with Alternaria padwickii. The enzyme activity in the seedlings challenged with the pathogen was two fold more over control. The suppression in disease incidence in growing plants indicated the promising effect of Dravya and Dithane M-45 under green- house conditions.

• The Korean Journal of Mycology
• /
• v.17 no.4
• /
• pp.229-232
• /
• 1989

A blight disease of carnation (Dianthus caryophyllus L.) caused by Alternaria dianthi was found in greenhouses and vinylhouses in southern Korea. In severely affected beds, many carnation plants were blighted and died. The growth of the fungus id vitro was optimum between 24 and $28^{\circ}C$. In controlled inoculations, A. dianthi caused lesions on leaves and stems of carnation plants.

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

• Research in Plant Disease
• /
• v.29 no.4
• /
• pp.363-376
• /
• 2023

Alternaria black spots or blights in cruciferous crops have been devastating diseases worldwide and led to economic losses in broccoli, Chinese cabbage, kale, radish, rapeseed, etc. These diseases are caused by different Alternaria spp., including A. brassicae, A. brassicicola and A. raphani transmitted from infected seeds or insect vectors. Efforts to excavate disease resistance traits of cruciferous crops against Alternaria black spots or blights have been demonstrated. Genetic resource of disease resistance was investigated in the wild relatives of cruciferous crops, and different cultivars were screened under different inoculation conditions. Development of the disease-resistant lines against Alternaria black spots or blights was also tried via genetic transformation of the cruciferous crops using diverse plant defence-associated genes. Plant immunity activated by pre-treatment with chemicals, i. e. β-amino-n-butyric acid and melatonin, was suggested for reducing Alternaria black spots or blights in cruciferous crops. The disease resistance traits have also been evaluated in model plant Arabidopsis originating from different habitats. Various plant immunity-related mutants showing different disease responses from wild-type Arabidopsis provided valuable information for managing Alternaria black spots or blights in cruciferous crops. In particular, redox regulation and antioxidant responses altered in the Alternaria-infected mutants were discussed in this review.

• Korean Journal Plant Pathology
• /
• v.1 no.1
• /
• pp.67-71
• /
• 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 of Medicinal Crop Science
• /
• v.20 no.5
• /
• pp.339-344
• /
• 2012

This study was carried out to research microorganisms having the antifungal activity against ginseng Alternaria blight pathogen Alternaria panax and ginseng anthracnose pathogen Colletotrichum gloeosporioides. Eleven Bacillus strains. were isolated from Korean traditional soybean paste and Kimchi. Among the 11 isolates, DJ5, KC1, KC2 and KC4 showing antagonistic activity on the mycelial growth of A. panax and C. gloeosporioides in pairing culture were finally selected as the antagonistic microorganisms. Based on 16s rRNA sequence and phylogenetic tree analysis, they were identified as Bacillus spp.. The selected microorganisms were investigated antagonistic activity by measured leaf-segment colonization in pot test. When Bacillus sp. were injected after A. panax treatment, KC1, KC2 and KC4 showed similar effect to chemical pesticides treated control. To measure preventive effect of Bacillus sp, antagonistic microorganisms were injected and C. gloeosporioides was treated in pot. When measuring the effectiveness for the prevention of Anthracnose, All Bacillus spp. showed approximately 83~90 % degree of superior preventive effect. In general, The four Bacillus spp. isolated from Korean traditional fermented foods showed therapeutic effect of Alternaria blight and preventive effect of Anthracnose.

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

• The Plant Pathology Journal
• /
• v.31 no.1
• /
• pp.78-82
• /
• 2015

In 2011, a leaf blight disease was observed on cosmos (Cosmos bipinnatus) leaves in Nonsan, Korea. The causal pathogen was isolated and identified based on morphological and molecular approaches. Morphological characteristics of the pathogen matched well with the Alternaria cosmosa and also easily distinguishable from Alternaria zinniae reported from cosmos seeds by producing branched beak. Phylogenetically, the pathogen could not be distinguished from A. passiflorae based on the sequence analysis of a combined data set of Alt a1 and gpd genes. However, A. passiflorae was distinguished from the present species by having conidiophores with 4 to 5 conidiogenous loci. The results indicate that the present Alternaria species is A. cosmosa. Pathogenicity tests revealed that the isolate was pathogenic to the leaves of Cosmos bipinnatus. This is the first report of Alternaria blight disease caused by A. cosmosa on cosmos in Korea.