• Research in Plant Disease
• /
• v.20 no.1
• /
• pp.50-53
• /
• 2014

Rhizopus soft rot of lily (Lilium longiflorum) caused by Rhizopus oryzae was observed in the experimental field in Taean Lily Experiment Station in Korea, 2012. The typical symptoms were water-soaked lesions on bottom stem and leaf rot. The lesion rapidly expanded and the plant was softened totally. The fungus grew vigorously at an optimum temperature ($25^{\circ}C$) and brownish colony and black sporangia were formed on potato dextrose agar medium. Sporangiophores formed on end of sporangia were sub-globose, brownish and $6-10{\mu}m$ in size. Sporangia were globose, blackish and $87-116{\mu}m$ in size. Sporangiospores were irregularly oval and sub-globose, brownish $4-8{\mu}m$ in size. On the basis of mycological characteristics, analyzing sequences of internal transcribed spacer region of ribosomal DNA, and pathogenicity test on host plants, the causal fungus was identified as R. oryzae. This is the first report of Rhizopus soft rot on lily caused by R. oryzae in Korea.

• Research in Plant Disease
• /
• v.8 no.1
• /
• pp.59-62
• /
• 2002

Anthracnose symptoms were observed on the community area in Sancheong-gun, Gyeongnam Province in Korea. The symptoms occurred on leaf and stem, and then plants eventually were died. Colony color was whitish gray to dark gray on potato dextrose agar. Conidia were single celled . colorless, cylindrical and was 10.2~20.4$\times$3.6$\times$6.0$\mu$m in size. Appressoria were dark brown, ovate to obovate and 6.2~10.5$\times$4.3$\times$8.6$\mu$m in size. Perithecia were brown to black in color and shaped as globose to obpyriform and 72.6~284.7$\mu$m in size. Asci were clavate to cylindrical in shape and 63.6~98.8$\times$8.3~12.5$\mu$m in size. Ascospores were cylindrical. fusiform, slightly curved at the center and 9.6~21.8$\times$4.0~6.0$\mu$m in size. Optimum temperature fur growth was 3$0^{\circ}C$. On the basis of mycological characteristics and pathogenecity test on host plants, the fungus was identified as Glomerella cingulata . This is the first report on the Anthracnose of achyranthes caused by Glomerella cingulata in Korea.

• Research in Plant Disease
• /
• v.11 no.2
• /
• pp.213-216
• /
• 2005

Tomato spotted wilt virus (TSWV) occurred abruptly with a high incidence rate in 14 vegetable crops in Anyang area, Gyunggido in 2004. TSWV was identified by the symptoms on the indicator plants, immunocaptured reverse transcription-polymerase chain reaction (IC/RT-PCR), virion captured (VC)RT-PCR and RT-PCR using total RNA from the infected plants. Vegetable crops infected with TSWV included table tomato, cherry tomato, red pepper, lettuce, chicory, red leaf chicory, red mustard, dragon tongue, treviso, potato, perilla, sesame, pumpkin, and ssamchoo (hybrid of oriental cabbage and cabbage). The incidence of TSWV in fields ranged from 30 to $100\%$. TSWV usually produced necrosis, wilt and/or severe mosaic with typical single or double ring spots on the leaves. TSWV could be detected in Frankliniella occidentalis collected from the crops in the fields with $90\%$ rate by IC/RT-PCR.

• Research in Plant Disease
• /
• v.30 no.2
• /
• pp.131-138
• /
• 2024

The effects of five fungicides on the spore growth phase of Alternaria dauci, which causes carrot leaf blight, were tested using the spore viability assay (SVA) and agar dilution method (ADM). The average EC₅₀ values for chlorothalonil against seven isolates of A. dauci examined by SVA and ADM were 14.21 ㎍/ml and more than 100 ㎍/ml. Dithianon and folpet also had lower EC₅₀ values in SVA than in ADM, while iminoctadine trisalbesilate had lower EC₅₀ value in ADM. For fluazinam, the EC₅₀ values of SVA and ADM were 1.63 and 2.40 ㎍/ml, respectively. As EC₅₀ values of five fungicides according to the spore growth phase of A. dauci KACC 42997, the efficacy of each fungicide as chlorothalonil, dithianon, and folpet decreased when treated after spore germination rather than when treated with spores before germination. However, iminoctadine tris-albesilate was more effective when treated after spores germinated than when treated before treatment. The excellent effect of fluazinam on the pathogen was maintained until A. dauci KACC 42997 was cultured in potato dextrose broth for 6 hr and the germ tube grew beyond the size of the spore. However, when treated with iminoctadine tris-albesilate and fluazinam after culturing for 12 hr, as the EC₅₀ values of the two fungicides increased to 8.87 and 20.65 ㎍/ml, their efficacies decreased. The results of this study show that the treatment time of the fungicide should be determined by considering the effect of the fungicide on the spore growth phase of pathogens.