In April 2002 and 2003, soft rot on fruit of eggplant (Solanum melongena) caused by Choanephora cucurbitarum was observed in the experimental fields at Gyeongnam Agricultural Research and Extension Services in Korea. The disease began with water-soaking and dark-green lesions, and then the infected tissues were rapidly rotten. Sporangium was subglobose in shape and sized 40~130 microm. Monosporous sporangiola were elliptic, fusiform or ovoid, brown in color, and measured as 12~20 x 6~14 microm. Sporangiospores having three or more appendages were elliptic, fusiform or ovoid in shape, dark brown or brown in color, and sized 14~20 x 7~16 microm. The fungus grew well on potato dextrose agar between 15 and 40degrees C and its optimum growth temperature was 30degrees C. Based on morphological characteristics, the causal fungus of the fruit soft rot of eggplant was identified as C. cucurbitarum. This is the first report on the soft rot of S. melongena caused by C. cucurbitarum in Korea.
Agar ; Fruit ; Fungi ; Glucose ; Korea* ; Solanum melongena* ; Solanum tuberosum ; Sporangia

Solanaceous crops grown in greenhouses and fields in Korea were surveyed from 1994 to 2000. Sclerotinia rot most severely occurred up to 60% in potato. Incidence of the disease was as high as 20% at its maximum in tomato and 5% in eggplant, but as low as less than 1% in red pepper. Symptoms of Sclerotinia rot commonly developed on stems of the solanaceous crops but rarely on fruits of eggplant and tomato. A total of 169 isolates of Sclerotinia species was obtained from the diseased solanaceous crops. Out of the isolates, 165 isolates were identified as S. sclerotiorum, and the others as S. minor based on their morphological and cultural characteristics. S. sclerotiorum was isolated from all the solanaceous crops, while S. minor was only isolated from tomato. Eight isolates of S. sclerotiorum and two isolates of S. minor were tested for their pathogenicity to the solanaceous crops by artificial inoculation. All the isolates of the two Sclerotinia spp. induced rot symptoms on stems of the solanaceous crops tested, which were similar to those observed in the fields. The pathogenicity tests revealed that there was no significant difference in the susceptibility of the solanaceous crops to the isolates of S. sclerotiorum. However, in case of S. minor, the potato cultivar Sumi was relatively less susceptible to the pathogen.
Ascomycota* ; Capsicum ; Cultural Characteristics ; Fruit ; Incidence ; Korea ; Lycopersicon esculentum ; Solanum melongena ; Solanum tuberosum ; Virulence

No abstract available.
Glucose* ; Solanum tuberosum* ; Trichophyton*

Background: A rise in the number of immunocompromised patients has increased the risk of opportunistic fungal infections. Identifying novel sources of antifungal agents from commonly discarded materials (i.e. potato peelings) can provide a cheaper alternative for antifungal drugs.

Objectives: The aim of the study was to determine the antifungal activity of crude glycoalkaloid extract from Solanum tuberosum L. (white potato) peelings against opportunistic fungi Candida albicans, Candida glabrata, Aspergillus niger, Aspergillus fumigatus, and Aspergillus flavus.

Methods: The glycoalkaloid content from dried potato peelings were extracted using ethanol and confirmed using colorimetric tests.The extract had a concentration 833.33 microgram/mL. Determination of the minimum inhibitory concentrations (MICs) of the extract via two-fold broth dilution was performed for the five fungi with amphotericin B and fluconazole as the reference antifungal drugs.

Results: MICs of the crude extract for C. albicans, C. glabrata, A. fumigatus, and A. niger were not found within the concentration range of the studies and would thus need further experiments using a broader range of glycoalkaloid concentrations. The extract was found to have a MIC of 104.17microgram/mL for A. flavus, thereby verifying the antifungal effect of glycoalkaloid against A. flavus at said concentration.

Conclusion: Glycoalkaloids from Solanum tuberosum are a potential source of antifungals against certain opportunistic fungi.

Aphids are one of the most destructive pests in crop production such as pepper, cucumber, and eggplants. The importance of entomopathogenic fungi as alternative pest control agents is increasing. Conidia of entomopathogenic fungi are influenced by environmental conditions, such as temperature and relative humidity, and cause slow and fluctuating mortality. These factors have prevented wider application and use of biocontrol agents. For investigation of means of mitigation of such problems, we conducted bioassays with 47 fungal culture filtrates in order to evaluate the potential of secondary metabolites produced by entomopathogenic fungi for use in aphid control. Among 47 culture filtrates cultured potato dextrose broth, filtrate of Beauveria bassiana Bb08 showed the highest mortality (78%) against green peach aphid three days after treatments. Filtrate of Bb08 cultured in Adamek's medium showed higher toxicity as 100% to third instar nymphs of the aphid compared with seven other filtrates cultured in different broths amended with colloidal chitin or oil. The culture filtrates and fungal cultures from media amended with colloidal chitin or oil had lower control efficacies than filtrates without these additives in three different media. These results indicate that the fungal culture fluid or culture filtrate of B. bassiana Bb08 cultured in Adamek's medium has potential for development as a mycopesticide for aphid control.
Aphids* ; Beauveria* ; Biological Assay ; Chitin ; Colloids ; Fungi ; Glucose ; Humidity ; Mortality ; Nymph ; Pest Control ; Prunus persica ; Solanum melongena ; Solanum tuberosum ; Spores, Fungal

No abstract available.
Acinetobacter baumannii ; Acinetobacter ; Colistin ; Solanum tuberosum

In this study, we identified the causative agent of stem-end rot in potatoes that were grown in Gangwon alpine areas of Korea in 2013. The disease symptoms included appearance of slightly sunken circular lesion with corky rot on the potato surface at the stem-end portion. The fungal species isolated from the infected potatoes were grown on potato dextrose agar and produced white aerial mycelia with dark violet pigments. The conidiophores were branched and monophialidic. The microconidia had ellipsoidal to cylindrical shapes and ranged from 2.6~11.4 x 1.9~3.5 microm in size. The macroconidia ranged from 12.7~24.7 x 2.7~3.6 microm in size and had slightly curved or fusiform shape with 2 to 5 septate. Chlamydospores ranged from 6.1~8.1 x 5.7~8.3 microm in size and were present singly or in pairs. The causal agent of potato stem-end rot was identified as Fusarium oxysporum by morphological characterization and by sequencing the internal transcribed spacer (ITS1 and ITS4) regions of rRNA. Artificial inoculation of the pathogen resulted in development of disease symptoms and the re-isolated pathogen showed characteristics of F. oxysporum. To the best of our knowledge, this is the first study to report that potato stem-end rot is caused by F. oxysporum in Korea.
Agar ; Fusarium* ; Gangwon-do ; Glucose ; Korea ; Solanum tuberosum* ; Viola ; Virulence

In July 2015, diseased leaves of black chokeberry (Aronia melanocarpa) were observed in Danyang and Gochang, Korea. The symptoms appeared as circular or irregular brown leaf spots, from which Alternaria tenuissima was isolated. The isolates were cultured on potato dextrose agar, and their morphological characteristics were observed under a light microscope. The colonies were whitish to ash colored. The pathogenicity test on healthy black chokeberry leaves produced circular brown spots, in line with the original symptoms. Molecular analyses of the ITS, GPD, RPB2, and TEF genes were conducted to confirm the identity of the pathogen. The phylogeny of the multi-gene sequences indicated that the causal agent was A. tenuissima. This study is the first report of A. tenuissima leaf spot on black chokeberry (A. melanocarpa).
Agar ; Alternaria* ; Glucose ; Korea* ; Photinia ; Phylogeny ; Solanum tuberosum ; Virulence

In March 2014, a kohlrabi stem rot sample was collected from the cold storage room of Daegwallyong Horticultural Cooperative, Korea. White and fuzzy mycelial growth was observed on the stem, symptomatic of stem rot disease. The pathogen was isolated from the infected stem and cultured on potato dextrose agar for further fungal morphological observation and to confirm its pathogenicity, according to Koch's postulates. Morphological data, pathogenicity test results, and rDNA sequences of internal transcribed spacer regions (ITS 1 and 4) showed that the postharvest stem rot of kohlrabi was caused by Sclerotinia sclerotiorum. This is the first report of postharvest stem rot of kohlrabi in Korea.
Agar ; Ascomycota* ; DNA, Ribosomal ; Glucose ; Korea ; Solanum tuberosum ; Virulence

The medicinal fungus Phellinus linteus, in the family Hymenochaetaceae, has been used as a traditional medicine for the treatment of various diseases. In this study, the chemical constituents of the culture broth of P. linteus were investigated. P. linteus was cultured in potato dextrose broth medium, and the culture broth was extracted with ethyl acetate. The ethyl acetate-soluble portion was concentrated and subjected to ODS column chromatography, followed by Sephadex LH-20 column chromatography. Six compounds (1~6) were purified by preparative reversed-phase high-performance liquid chromatography. Spectroscopic methods identified their structures as caffeic acid (1), inotilone (2), 4-(3,4-dihydroxyphenyl)-3-buten-2-one (3), phellilane H (4), (2E,4E)-(+)-4'-hydroxy-gamma-ionylideneacetic acid (5), and (2E,4E)-gamma-ionylideneacetic acid (6). Compounds 1, 2, and 3 exhibited potent dose-dependent antioxidant activity.
Chromatography ; Chromatography, Liquid ; Fungi ; Glucose ; Humans ; Medicine, Traditional ; Solanum tuberosum