• Research in Plant Disease
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• v.11 no.1
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• pp.85-87
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• 2005

In July 2003, a destructive stem rot occurred sporadically in an exhibition farm on Aster glehni of Hamyanggun, Gyeongsangnam-do Agricultural Research and Extension Services, Korea. The typical symptoms of the disease were water-soaking, stem rot, wilt or blight. The infected plants were mostly died. White mycelial mats were spread over lesions and sclerotia were formed on stems and near soil line. The sclerotia were globoid or irregular in shape, 1~3 mm in size, and white to brown in color. The optimum temperature for fungal growth was about 30oC. Clamp connections were observed in the hyphae of the fungus grown on potato dextrose agar, and hyphal diameter was 3~8 ${\mu}m$. On the basis of mycological characteristics and test of pathogenicity to host plants, the fungus was identified as Sclerotium rolfsii. This is the first report on the stem rot of Aster glehni caused by S. rolfsii in Korea.

• Research in Plant Disease
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• v.9 no.1
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• pp.28-31
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• 2003

A sclerotinia rot was occurred on the stems of Obedient plant (Physostegia virginiaqna) grown in the exhibition field of Gyeongsangnam-do Agricultural Research and Extension Services, Korea in 2002. The typical symptoms of the disease were that the infected leaves and stems, at first, became dark green, then watery and soft rotted, later, White fluffy mycelia formed on the lesion developed black sclerotia, later, Sclerotia formed on the plants and PDA medium were globose to cylindrical or irregular in shape and 1.0~10.3$\times$1.0~8.4 mm in size. Aphothecia were cup-shape with numerous asci and 0.8~1.8 cm in diameter, Asci were cylindrical in shape and 84~286$\times$4.7~26.3 ${\mu}{\textrm}{m}$ in size. Ascospores were one cell hyaline, ellipsoid to ovoid in shape, and 7.6~12.8$\times$3.4~6.2 ${\mu}{\textrm}{m}$ in size. The optimum temperature far mycelial growth was $25^{\circ}C$. This is the first report on the sclerotinia rot of Physostegia virginiaqna caused by Sclerotinia sclerotiorum in Korea.

• Research in Plant Disease
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• v.18 no.1
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• pp.54-56
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• 2012

Sclerotium rot of sponge gourd occurred at the experimental field of Gyeongsangnam-do Agricultural Research and Extension Services in August 2010. The infected fruits showed water-soaked and rot symptoms. White mycelial mats spread over lesions, and then sclerotia were formed on fruit and near soil line. The sclerotia were globoid in shape, 1-3 mm in size and white to brown in color. The optimum temperature for mycelial growth and sclerotia formation on PDA was $30^{\circ}C$ and the hyphal width was 4-8 ${\mu}m$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. On the basis of mycological characteristics, ITS rDNA sequence analysis, and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report of sclerotium rot on sponge gourd caused by S. rolfsii in Korea.

• Research in Plant Disease
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• v.12 no.2
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• pp.122-124
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• 2006

Sclerotinia rot was occurred on the leaf and stem of Fatsia japonica in Geoje city, Gyeongnam province in Korea from 2004 to 2005. The typical symptom of the disease was water-soaked infected leaves and stems. The colony of the isolated fungus was white to faintly gray in color. Apothecia were cup-shaped with numerous asci and $0.8{\sim}1.3 cm$ in size. Asci were cylindrical in shape and $70{\sim}220{\times}4{\sim}18{\mu}m$ in size. Ascospores were aseptate, hyaline, ellipsoid in shape, and $6{\sim}12{\times}4{\sim}6{\mu}m$ in size. Sclerotia formed on the plants and PDA medium were globose to cylindrical or irregular in shape, black in color. The optimum temperature for mycelial growth was $25^{\circ}C$. This is the first report on the Sclerotinia rot of Fatsia japonica caused by Sclerotinia sclerotiorum in Korea.

• Research in Plant Disease
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• v.27 no.3
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• pp.115-119
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• 2021

Sclerotinia rot was occurred on the leaf and stem of Peucedanum japonicum Thunb. in greenhouse field of Pohang city of Gyeongbuk province in Korea. The typical symptom of the disease was light brown spot and tipburn on infected leaves. The colony of the isolated fungus was white to light gray in color. Asci were cylindrical shape and 75-240×5.9-17.3 ㎛ in size. Apothecia were cup-shaped with numerous asci and 0.5-0.9 cm in size. Ascospores were aseptate and ellipsoid in shape, and 8.4-10.7×4.8-5.8 ㎛ in size. Sclerotia formed on the plants and potato dextrose agar medium were globose to irregular in shape and black in color. Partial sequencing of rDNA of this isolate showed that it was 100% consistent with that of Sclerotinia sclerotiorum. It was confirmed that the same lesion was formed by reinoculating this pathogen on a healthy P. japonicum Thunb. and the same strain was isolated. This is the first report on the Sclerotinia rot of P. japonicum Thunb. caused by S. sclerotiorum in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.257-265
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• 1996

To obtain the basic informations necessary to develop the production technology of vegetable soybean seeds, this study was conducted at the National Crop Experiment Station, RDA, Suwon, Korea in 1993. Seeds of three vegetable soybean varieties, 'Mikawashima', 'Hwaeomputkong', and 'Seokryangputkong' produced at Pyeongchang, a highland in Korea and introduced from Japan were planted on April 20 in the field. The emergence rate among varieties was significanlty different. Emergence rate of seeds produced at Pyeongchang was higher by 7% than that of the seeds from Japan. Rate of pod infection by Phamapsis spp., brown spot by Septaria glycines, soybean mosaic virus(SMV), and downy mildew by Peronospora manshurica in the field was not different between locations. The growth characteristics, yield components, and green pod and grain yields were not different between locations. Therefore, it was proved that the production of vegetable soybean seeds with the better quality and higher emergence is possible in highland, Korea. possible in highland, Korea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.37-37
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• 2020

홍띠(Imperata cylindrica 'Rubra') 식물자원의 생장점 부위를 기내 배양하여 기내 식물체 재분화와 재분화식물체의 유전적 안정성을 검토하였다. 기내배양은 26±2 ℃, 25 μmol/m²/s, 14h/10h (day/night) 광조건 하의 배양실에서, MS (Murashige and Skoog, 1962) 기본배지에 생장조절물질을 첨가하여 조직절편체로부터 식물체를 유도하였다. 캘러스는 MS기본배지에 0.1 mg/L의 2,4-D와 2 mg/L의 BA를 혼용처리하여 생장점 부위로부터 유도하였다. 캘러스 증식은 MS기본배지에 0.1 mg/L의 2,4-D를 첨가한 배지에서, 이들 캘러스로부터 신초 재분화는 0.01 mg/L의 NAA 및 2 mg/L의 BA를 첨가한 배지에서 유도하였다. 다경줄기 형성(multiple shooting) 후 MS배지에서 4주 동안 배양한 재분화식물체는 멸균한 상토(버미큘라이트)를 포함한 배양병에서 7주간 배양한 다음 점차적으로 배양병 뚜껑을 개방(1/10 정도 1차 개방 1주일, 3/10 정도 2차 개방 2주일)하여 직경 6 cm의 컵포트에 이식하여 활착시켰다. 재분화식물체는 붉은색이 사라지고 녹색을 나타내었으며, 일부개체에서만 잎의 일부분만 붉은색을 나타냈다. 이는 생장점 주변조직에서 유래한 재분화체가 우세함으로써 생장점보다는 생장점 주변의 조직을 구성하는 녹색층에서 주로 식물체가 재생되는 것으로 판단된다. 이에 따라 홍띠 대조구식물체 8개체, 활착한 녹색 재분화 식물체 20개체(실내 재배중인 순화체 10개체, 2020년 6개월간 포장에서 재배중인 순화체 10개체)를 대상으로 ISSR분석을 실시하여 재분화식물체의 유전적 안정성을 검토하였다. 향후 조직학적 측면에서 신초재분화의 기원에 대한 검토가 필요하다고 사료된다.

• Korean Journal of Environmental Agriculture
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• v.37 no.1
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• pp.34-40
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• 2018

BACKGROUND: In order to select a fungicide that can effectively control anthracnose disease in Japanese plum fruit, mycelial growth inhibition effect and spore germination inhibition effect of six fungicides were tested in vitro against six isolates of Colletotrichum acutatum and five isolates of C. gloeosporioides that were isolated from diseased Japanese plum fruit. METHODS AND RESULTS: Inhibitory effects of fungicides on mycelial growth were investigated after inoculating each isolate on potato dextrose agar amended with four discriminatory concentrations of each fungicide for 7 days at $25^{\circ}C$. For spore germination inhibitory effect, each isolate of the Colletotrichum spp. was cultured in potato dextrose agar for 7-14 days at $25^{\circ}C$. After adjusting the concentration of spores of each isolate to $1{\times}10^6mL^{-1}$ by diluting with 0.025% PDB, the spore suspension was mixed with each fungicide (1:4, v/v), and $60{\mu}L$ aliquots were dispensed to sterile hole slide glass. Hole slide glasses were placed in a humidified box and incubated for 15 hours at $25^{\circ}C$. Then, spore germination was observed under an optical microscope. At recommended concentration of fungicide prochloraz manganese showed the highest mycelial growth inhibitory effect and dithianon showed the lowest mycelial growth inhibition. The $EC_{50}$ values for the inhibition of spore germination by dithianon and pyraclostrobin were $0.069-0.126{\mu}g/mL$ and $0.37-1.59{\mu}g/mL$, respectively. Although benomyl, prochloraz manganese, azoxystrobin, and tebuconazole did not inhibit the spore germination, they appeared to restrain mycelial growth by abnormal growth of germ tube and mycelium after germination. CONCLUSION: Dithianon seemed to have preventive effect. Prochloraz manganese, azoxystrobin, and tebuconazole were likely to have control effect. Pyraclostrobin is considered to have both preventive and control effect against anthracnose disease of Japanese plum fruit.

• Research in Plant Disease
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• v.17 no.3
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• pp.288-294
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• 2011

Rice bakanae disease, caused by the fungus Fusarium fujikuroi, is one of the most important rice diseases and distributed widely in Asia. Resistance screening system in rice field had been established. However, the evaluation results of the system vary according to the environmental conditions when the test is conducted. To develop precise and rapid evaluation method of disease resistance of rice to bakanae disease, in vitro screening system was attempted in this study. The six cultivars namely, 'Nampyeongbyeo', 'Junambyeo', 'Chucheongbyeo', 'Samcheonbyeo', 'Odaebyeo' and 'Hwasinbyeo' were tested. They were planted onto MS agar medium (10 ml) in test tube ($450\;mm{\times}{\phi}30\;mm$) and incubated at $25^{\circ}C$ and $28^{\circ}C$ in growth chamber under 12 hr light condition. Symptoms of over growth appeared a few days after seeding and then seedling were withered 2-3 weeks after over growth. The disease symptoms such as leaf dryness on top of rice were appeared in the 'Nampyeongbyeo' from 28 days at the concentration of $10^5$ spores/ml culturing at $28^{\circ}C$ and then withered completely 35 days after seeding. Whereas the other varieties withered entirely 19-23 days after seeding. Using the in vitro seedling screening method, 72 rice varieties were investigated to select resistant cultivar. Finally, two resistant cultivars ('Nampyeongbyeo' and 'Inwolbyeo') and seven moderately resistant cultivars ('Hwadongbyeo', 'Seokjeongbyeo', 'Samgwangbyeo', 'Sampyeongbyeo', 'Nonghobyeo', 'Heukjinjubyeo' and, 'Joanbyeo') were selected. If in vitro seedling screening method was used for evaluation of bakanae disease resistance, it would be completed within 35 days after sowing of rice seed.

• Korean Journal of Breeding Science
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• v.42 no.4
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• pp.390-396
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• 2010

A weedy rice, Ganghwaaengmi 11, shows high level of leaf blast resistance. The chromosomal number and locations of genes conferring the leaf blast resistance were detected by QTL (quantitative trait loci) analysis using SSR markers in the 120 RILs (recombinant inbred lines) derived from the cross between Nagdongbyeo and Ganghwaaengmi 11. Ganghwaaengmi 11 expressed compatibility with 20 of the 45 inoculated blast isolates, in contrast to Nagdongbyeo with 44 compatible isolates. To identify QTLs affecting partial resistance, RILs were assessed in upland blast nursery in three regions and inoculated with selected nine blast isolates. QTLs for resistance to blast isolates were identified on chromosomes 7, 11 and 12. Three QTLs associated with blast resistance in nursery test at three regions were also detected on chromosomes 7, 11 and 12. The QTL commonly detected on chromosome 12 was only increased blast resistance by Ganghwaaengmi 11 allele. This QTL accounted for 60.3~78.6% of the phenotypic variation in the blast nursery test. OSR32 and RM101 markers tightly linked to QTL for blast resistance on chromosome 12 might be useful for marker-assisted selection (MAS) and gene pyramiding to improve the blast resistance of japonica rice.