• Journal of Ginseng Research
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• v.26 no.3
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• pp.151-158
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• 2002

Ginseng (Panax quinquefolius L.) has become one of the most valuable herb crops grown in North America. However, traditional cropping practices are favourable to disease and significant losses due to root disease are common, despite frequent use of fungicides. Seedlots are often contaminated with pathogens, however, little is known about the causes of seed decay and the role of seed pathogens as incitants of root rots. It was shown that both Fusarium spp. and Cylindrocarpon destructans were able to rot seeds and that C. destructans was more virulent than Fusarium spp. on seedling roots. A modified rose bengal agar MRBA) medium (1 g KH$_2$PO$_4$; 0.5 g MgSO$_4$; 50 mg rose bengal; 10 g dextrose; 5 g Bacto peptone; 15 g Bacto agar; 30 mg streptomycin sulfate; 250 mg ampicillin; 10 mg rifampicin; 500mg pentachloronitrobenzene; 500 mg dicloran; and 1 L distilled water) was superior to potato dextrose agar in detecting C. destuctans in diseased roots. Isolation of C. destructans from diseased seedlings arising from seeds sown in replant soil supported the hypothesis that this pathogen is a cause of ginseng replant failure in North America.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.101-101
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• 2020

• Korean Journal of Medicinal Crop Science
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• v.26 no.3
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• pp.248-253
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• 2018

Background: Dazomet are widely used as soil fumigant to solve soilborne problems, and the degradation intermediates are toxic to nematodes, fungi, bacteria, insects and weeds. Methods and Results: The effects of cultivation of green manure crop, maize before and after soil fumigation on the control of ginseng root rot disease were compared using soil where 6-years-old ginseng was harvested. Fumigant (dazomet) were used for soil fumigation in May and September, respectively. Maize was grown for soil management before and after soil fumigation. After May fumigation, the sowing date of maize was delayed by 15 days and thus its dry weight was decreased significantly. Maize cultivation after May fumigation increased pH but decreased EC, $NO_3$, $P_2O_5$, and K significantly. Maize cultivation after May fumigation decreased fungi population and the ratio of fungi and bacteria. Growth of 2-years-old ginseng was improved and the incidence of ginseng root rot was significantly decreased by maize cultivation after May fumigation. After harvesting 2-years-old ginseng, the population of Cylindrocarpon destructans was not different between treatment of May and September, but Fusarium solani showed a significant increase in September fumigation after maize cultivation. Conclusions: Maize cultivation after soil fumigation was effective in inhibiting ginseng root rot by the amendment of mineral composition and microorganism in fumigated soil.

• Korean Journal of Medicinal Crop Science
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• v.27 no.4
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• pp.284-291
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• 2019

Background: Ginseng root rot disease, caused by Cylindrocarpon destructans and Fusarium solani is a major cause of replant failure in continuous cropping ginseng. Methods and Results: To control replant injury in soil infected with C. destructans and F. solani, biosolarization was performed by covering the plot with transparent polyethylene film after adding green manure of maize and sunflower for the summer season. Per 10 a, fresh and dry weight of maize was 10.1 and 2.5 tons, respectively, and that of sunflower was 8.1 tons and 1.2 tons, respectively. Mean maximum temperature at 20 cm depth was $33.2^{\circ}C$, $41.5^{\circ}C$ and $41.8^{\circ}C$ in the control, maize-incorporated and sunflower-incorporated plots, respectively. The elapsed time over $40^{\circ}C$ was 36.4 h in the maize-incorporated plot and 77.3 h in the sunflower-incorporated plot. Biosolarization increased $NO_3$ content in soil, while content of organic matter, Ca, and Mg was decreased. Electrical conductivity, $NO_3$ and $P_2O_5$ in soil significantly increased after two years of biosolarization. The number of spores of C. destructans in soil was significantly decreased by biosolarization, and sunflower treatment was more effective than maize treatment in decreasing the number of spores. Root yield of 3-year-old ginseng was significantly increased by biosolarization, however, there was no significant difference between maize and sunflower treatments. Rate of root rot in 3-year-old ginseng decreased to 16.5% with the incorporation maize and 5.0% with the incorporation of sunflower, while that in control 25.6%. Conclusions: Biosolarization was effective in inhibiting ginseng root rot by decreasing the density of root rot disease and improving soil chemical properties.

• Korean Journal of Medicinal Crop Science
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• v.24 no.4
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• pp.294-302
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• 2016

Background: Crop rotation plays an important role in improving soil chemical properties, minimizing the presence of disease pathogens, and assists in neutralizing autotoxic effects associated with allelochemicals. Methods and Results: Five rotation crops of sudan grass, soybean, peanut, sweet potato, and perilla were cultivated for one year with an aim to reduce yield losses caused by repeated cropping of ginseng. In 2-year-old ginseng grown in the same soil as a previous ginseng crop, stem length and leaf area were reduced by 30%, and root weight per plant was reduced by 56%. Crop rotation resulted in a significant decrease in electrical conductivity, $NO_3$, and $P_2O_5$ content of the soil, whereas organic matter, Ca, Mg, Fe, Cu, and Zn content remained-unchanged. Soil K content was increased following crop rotation with sudan grass and peanut only. Rotation with all alternate crops increased subsequent ginseng aerial plant biomass, whereas root weight per plant significantly increased following crop rotation with perilla only. A significant positive correlation was observed between root rot ration and soil K content, and a significant negative correlation was observed between ginseng root yield and the abundance of actinomycetes. Crop rotation affected the soil microbial community by increasing gram negative microbes, the ratio of aerobic microbes, and total microbial biomass whereas decreases were observed in actinomycetes and the ration of saturated fatty acids. Conclusions: In soil exhibiting crop failure following replanting, crop rotation for one year promoted both soil microbial activity and subsequent ginseng aerial plant biomass, but did not ameliorate the occurrence of root rot disease.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.1-9
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• 2019

Background: Korean ginseng is an important cash crop in Asian countries. However, plant yield is reduced by pathogens. Among the Ilyonectria radicicola-species complex, I. mors-panacis is responsible for root-rot and replant failure of ginseng in Asia. The development of new methods to reveal the existence of the pathogen before cultivation is started is essential. Therefore, a quantitative real-time polymerase chain reaction method was developed to detect and quantify the pathogen in ginseng soils. Methods: In this study, a species-specific histone H3 primer set was developed for the quantification of I. mors-panacis. The primer set was used on DNA from other microbes to evaluate its sensitivity and selectivity for I. mors-panacis DNA. Sterilized soil samples artificially infected with the pathogen at different concentrations were used to evaluate the ability of the primer set to detect the pathogen population in the soil DNA. Finally, the pathogen was quantified in many natural soil samples. Results: The designed primer set was found to be sensitive and selective for I. mors-panacis DNA. In artificially infected sterilized soil samples, using quantitative real-time polymerase chain reaction the estimated amount of template was positively correlated with the pathogen concentration in soil samples ($R^2=0.95$), disease severity index ($R^2=0.99$), and colony-forming units ($R^2=0.87$). In natural soils, the pathogen was recorded in most fields producing bad yields at a range of $5.82{\pm}2.35pg/g$ to $892.34{\pm}103.70pg/g$ of soil. Conclusion: According to these results, the proposed primer set is applicable for estimating soil quality before ginseng cultivation. This will contribute to disease management and crop protection in the future.

• Korean Journal of Medicinal Crop Science
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• v.23 no.3
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• pp.223-230
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• 2015

To study the effect of crop rotation on the control of ginseng root rot, growth characteristics and root rot ratio of 2-year-old ginseng was investigated after the crops of 18 species were cultured for one year in soil contaminated by the pathogen of root rot. Fusarium solani and Cylindrocarpon destructans were detected by 53.2% and 37.7%, respectively, from infected root of 4-year-old ginseng cultivated in soil occurring the injury by continuous cropping. Content of $NO_3$, Na, and $P_2O_5$ were distinctly changed, while content of pH, Ca, and Mg were slightly changed when whole plant of crops cultured for one year were buried in the ground. All of EC, $NO_3$, $P_2O_5$, and K were distinctly increased in soil cultured sudangrass, peanut, soybean, sunnhemp, and pepper. All of EC, $NO_3$, $P_2O_5$, and K among inorganic component showed negative effect on the growth of ginseng when they were excessively applied on soil. The growth of ginseng was promoted in soil cultivated perilla, sweet potato, sudangrass, and welsh onion, while suppressed in Hwanggi (Astragalus mongholicus), Deodeok (Codonopsis lanceolata) Doraji (Platycodon grandiflorum), Gamcho (Glycyrrhiza uralensis), Soybean. All of chicory, lettuce, radish, sunnhemp, and welsh onion had effective on the inhibition of ginseng root rot, while legume such as soybean, Hwanggi, Gamcho, peanut promoted the incidence of root rot. Though there were no significant correlation, $NO_3$ showed positive correlation, and Na showed negative correlation with the incidence of root rot.

• Korean Journal of Medicinal Crop Science
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• v.24 no.2
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• pp.136-142
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• 2016

Background: Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replant failure in ginseng fields. Methods and Results: Solarization of infested greenhouse soil was carried out during the summer season after applying green manure (Sudan grass) and Calcium Cyanamide (CC) on the soil. Mycelium and conidia of C. destructans died at $40^{\circ}C$ after 15 h, but they did not die at $35^{\circ}C$ after 15 h. They also died after keeping the soil at $40^{\circ}C$ for 2 h daily for 9 days, and at $45^{\circ}C$ for 8 days, but they did not die at $38^{\circ}C$ for 9 days. Maximum soil temperature was $55.4^{\circ}C$ at 5 cm depth, $48.7^{\circ}C$ at 10 cm, $44.7^{\circ}C$ at 15 cm, $42.5^{\circ}C$ at 20 cm, and $31.9^{\circ}C$ at 30 cm by incorporating green manure into the soil and using solarization. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. However, the addition of CC decreased the root weight due to the increase in EC and $NO_3-N$. Conclusions: Soil disinfection using green manure and solarization in a greenhouse environment was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.2
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• pp.89-109
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• 1999

Vascular spasm which has been reported to occur in 25% of clinical cases continues to be a problem in microvascular surgery; When prolonged and not corrected, it can lead to low flow, thrombosis, and replant or free flap failure. Ischemia, intimal damage, acidosis and hypovolemia have been implicated as contributors to the vascular spasm. Although much work has been done on the etiology and prevention of vasospasm, a spasmolytic agent capable of firmly protecting against or reversing vasospasm has not been found. Therefore vascular freezing was introduced as a new safe method that immediately and permanently relieves the vasospasm and can be applied to microsurgical transfers. Cryosurgery can be defined as the deliberate destruction of diseased tissue or relief the vascular spasm in microvascular surgery by freezing in a controlled manner. 96 Sprague Dawley rats each weighing within 250g were used and divided into 2 group, experimental 1 and 2 group. In the experimental 1 group, right epigastric vessels (artery and vein) were freezed with a cryoprobe using $N_2O$ gas for 1 min. In the experimental 2 group, after freezing for 1 min, thawing for 30 secs and repeat freezing for 30 secs. Left side was chosen as control group in both group. We sacrified the experimental animals by 1 day, 3 days, 1 week, 2 weeks, 4 weeks & 5 months and observed the sequential change that occur during regeneration of epigastric vessels using a histologic, histomorphometric, immunohistochemical and SEM study after the vascular freezing. The results were as follows1. In epigastric arteries, internal diameters had statistically significant enlargement in 1 day, 3 days of Exp-1 group and 1 day, 3 days, 1 week & 2 weeks of Exp-2 group. Wall thickness had statistically significant thinning in 2 weeks of Exp-2 group. 2. In epigastric veins, internal diameters had enlargement of statistical significance in 1 day of Exp-1 and Exp-2 group. 3. The positive PCNA reactions in smooth muscle appeared in 1 week and increased until 2 weeks, decreased in 4 weeks. There was no statistical significance between Exp-1 and Exp-2 group. 4. The positive ${\alpha}$-SMA reaction in smooth muscles showed weak responses until 1 week and slowly increased in 2 weeks and showed almost control level in 4 weeks. 5. The positive S-100 reactions in the perivascular nerve bundles showed markedly decrease in 1 day, 3 days and increased after 1 week and showed almost control level in 4 weeks. Exp-1 group had stronger response than Exp-2 group. 6. In SEM, we observed defoliation of endothelial cell and flattening of vessel wall. Exp-2 group is more destroyed and healing was slower than Exp-1 group. To sum up, relief of vasospasm (vasodilatation) by freezing with cryoprobe was originated from the damage of smooth muscle layer and perivascular nerve bundle and the enlargement of internal diameter in vessels was similar to expeimental groups, but Exp-2 group had slower healing course and therefore vessel freezing in microsurgery can be clinically used, but repeat freezing time needs to be studied further.