• Mycobiology
• /
• v.31 no.3
• /
• pp.173-178
• /
• 2003

India has maximum genetic materials in early cauliflower, which grow in subtropical conditions. Different disease parameters like linear growth, maximum growth rate per day, AUDPC, apparent infection rate and percent diseased area were calculated in artificially inoculated plants. Apparent infection rate is not co-related with the black rot disease incidence and should never be considered during characterization of disease resistance and varietal screening. Based on the above disease parameters Kunwari-18, Phool Gobhi Kunwari, Kataki-7 and BT-10-2 were selected as moderately resistance to black rot in early cauliflower. These lines can be used for black rot prone area and also for black rot disease improvement programme. Considering the qualitative and quantitative parameters, slow rotting resistance cauliflower lines are selected as such for cultivation and would be best suited in integrated disease programme.

• Korean Journal Plant Pathology
• /
• v.14 no.3
• /
• pp.209-211
• /
• 1998

Black dot root rot occurred severely in greenhouse tomatoes in jangseong area of Korea in April, 1996. The causal fungus of the disease was identified as Colletotrichum coccodes based on the morphological and cultural characteristics. Pathogenicity tests revealed that isolates of the fungus were responsible for the disease, and two cultivars of cherry tomato were less susceptible to the disease than other cultivars of tomato and cherry tomato tested.

• The Korean Journal of Mycology
• /
• v.11 no.2
• /
• pp.99-101
• /
• 1983

Black root rot caused by Cylindrocladium crotalariae is one of the most serious soilborne disease in soybean. Plant height reduction of Hwangkeum Kong was 38% by the rotting of the whole main root and 9% by rotting of the half of the main root as compared with partial discoloration in the main root. Pod number per plant and seed weight were significantly reduced by the increase of the disease severity. Important yield components such as number of pods per plant and seed weight were negatively correlated with the soybean black root rot severity.

• The Plant Pathology Journal
• /
• v.18 no.1
• /
• pp.54-55
• /
• 2002

Soaked black rot symptom was observed on the stem of Angelica acutiloba from July to August 2000 at Kumsan, Chungnam in Korea. This disease usually occurred under humid and high temperature conditions. The lesions on the stem appeared as soft rot with brown elliptical spots, which developed into large black spots at a later stage. When the bacterial isolates from the diseased plants were inoculated onto healthy plants by artificial needle prick method, symptoms similar to that observed in the fields developed. According to the cultural characteristics and pathogenicity of the isolates on the host plant the causal bacterium was identified as Xanthomonas campestris. This study proposed that the disease be named "bacterial black stem rot of A. acutiloba"loba".

• Korean journal of applied entomology
• /
• v.4
• /
• pp.25-28
• /
• 1965

The study was carried on a new disease of rice seedling which named 'Black rot of rice seedling'. None of papers on this disease was reported recently. The symptom of this disease was quite different from other seedling rot of rice plant. Submerged mycelial growth in water was black colored and it was surrounded whole surface of seed. Soil on which diseased seedlings were placed was black colored by this disease and the seedlings, finally stopped to grow within 3 em in height, and appeared with black rot symptom. Sporulation of the pathogen does not occurred under both of natural and artificial conditions. The mycelium appeared in dark color and with distinguished septation under the microscope. With those results it is easily recognized that the pathogen does not belong to those which causal organism:; of other seedling rot of rice plant like as Phycomycetes or Fusarium species. The study should be continued on identification of the causal organism. Favorable environments for the disease did not differ from other seedling rot of rice plant, and varietal resistance also did not significantly differ among the varieties used in this experiment. Dissemination of the disease was carried out not by planted seeds but by infected soil.

• The Plant Pathology Journal
• /
• v.25 no.1
• /
• pp.1-5
• /
• 2009

Root rot caused by Cylindrocarpon destructans is one of the most important diseases of ginseng (Panax ginseng C. A. Meyer). Two types of symptoms found in ginseng root rot are black root rot and rusty root (rusty spots), in which disease severities are high and low, respectively. Symptom development and related histopathological changes were examined in an inoculation test on 2-year-old ginseng roots using virulent (Cy9801) and avirulent (Cy0001) isolates of C. destructans under different temperature conditions (13, 18, 23, and $28^{\circ}C$). Black root rot was only induced by Cy9801 in the lower temperature range (13, 18, and $23^{\circ}C$) and not at the higher temperature ($28^{\circ}C$). No black root rot, but only rusty spot symptoms, were induced by Cy0001 at all temperatures tested except $13^{\circ}C$, at which no symptoms occurred on over half of inoculation sites, suggesting disease development was influenced by pathogen virulence and temperature. Wound periderms were formed in all root tissues with rust spot symptoms at $28^{\circ}C$ caused by Cy9801 and at 18, 23, and $28^{\circ}C$ temperatures caused by Cy0001. No wound periderm was formed at $13^{\circ}C$ by either Cy9801 or Cy0001. Light microscopy revealed that the wound periderm was formed by initial cell divisions in cell wall formation and/or additional cell wall layering in parenchyma cells without obvious nuclear division, followed by layering of the divided cells adjacent to the inoculation sites, blocking the spread of the rot. These results suggest that disease development declined at lower temperatures and by the formation of a wound periderm at higher temperatures, and that ginseng rusty root may develop under conditions unfavorable for further disease development of C. destructans.

• The Korean Journal of Mycology
• /
• v.8 no.1
• /
• pp.53-57
• /
• 1980

An undescribed black root rot of soybean, caused by Cylindrocladium crotalariae, was observed in Suweon area. The diseased plants showed yellowing at the top and dry rot at the root. Lesions of roots and stems in the soil were red to brown and main roots were cracked. Although not observed the disease in the field, leaves of inoculated test plants in the greenhouse exhibited circular, brown lesion surrounded by chloratic halos. The fungus was recovered in culture from the infected stem and root, and the perithecia of Calonectria crotalariae were demonstrated to be present as well as the cylindrocladium state. The fungus was pathogenic to the root, stem, petioles and leaves of soybean. The probable source of primary inoculum was microsclerotia formed in infected soybean root and stem from the previous season's soybean debris. Black root rot by this fungus was considered to be one of detrimental factors to the maximum yield of soybean. From the morphological and physiological characteristics and pathogenic behaviors, this fungus was identified as Cylindrocladium(Calonectria) crotalariae.

• Research in Plant Disease
• /
• v.24 no.4
• /
• pp.321-327
• /
• 2018

In 2018, symptoms of black rot on apple (Malus pumila var. dulcissima KOIDZ) cv. Fuji were observed in Yeongcheon-si, Korea. The fruit decay symptoms consisted of purple pimples spots, black rot around the seed cavity (calyx end), mummified fruit. To isolate the causal agent, small fragment (2 to 3 mm) of decayed tissue from the lesion margin were placed on WA or PDA. Fungal colonies on PDA produced dense white aerial mycelium, becoming dark gray with age. Pycnidia and conidia were observed under a light microscopy. The shapes of conidia were aseptate, ovoid, rounded at both ends, and $21.7-28.3{\times}9.9-15.3{\mu}m$. Based on morphological and cultural characteristics, this fungus was identified as Diplodia seriata. To confirm its identity, two loci (ITS and ${\beta}$-tubulin) were sequenced for molecular identification. BLAST searches indicated 100% identity with D. seriata. A pathogenicity test was conducted with isolates on Fuji apples. The apples were inoculated with mycelial plugs (5 mm) from 7-day-old cultures of the putative pathogens. All inoculated apples developed rot symptoms identical to the original symptoms, from which D. seriata were reisolated, fulfilling Koch's postulates. This study is the first report of black rot caused Diplodia seriata on apple.

• Research in Plant Disease
• /
• v.10 no.4
• /
• pp.268-271
• /
• 2004

Occurrence and soil fumigation effect on black root rot of peony was investigated. Peony was severely infected to black root rot caused by Cylindrocarpon destructans in continuous cropping field, but in first cropping field was less infected. To control black root rot, soil improvement, soil fumigation and the root dipping in chemicals were trialed in peony continuous cropping field. Black root rot was not decreased by soil improvement, but incidence of black root rot of peony cultivated in continuous croping field of peony was decreased by soil fumigation with Dazomet GR. and dipping of peony root in chemicals.

• Research in Plant Disease
• /
• v.19 no.1
• /
• pp.49-54
• /
• 2013

Sclerotinia white rot disease was observed on 5 and 6-year-old ginseng (Panax ginseng) roots in Hongchun, Cheorwon, and Yanggu, Gangwon Province, Korea from 2006 to 2010. Symptoms included a brownish watery soft rot of the roots, and black sclerotia were often found on the rotten roots. The causal agent of the disease was identified as Sclerotinia nivalis based on cultural characteristics and sequence analyses of the internal transcribed spacer region of rDNA and ${\beta}$-tubulin gene with 100% sequence similarity. Pathogenicity tests were performed on 2-year-old ginseng roots with mycelium plugs without wounds. A watery soft rot of the roots and black sclerotia were observed 10 days after inoculation. These symptoms were identical to those observed on naturally infected roots. The same fungus was re-isolated from the lesions induced by artificial inoculation. This is the first report of sclerotinia white rot caused by S. nivalis on P. ginseng in Korea.