• Horticultural Science & Technology
• /
• v.18 no.6
• /
• pp.797-801
• /
• 2000

The present study was conducted to improve the efficiency of transformation mediated by Agrobacterium tumefaciens in hot pepper. Both regeneration ratio and transformation frequency after the cocultivation with A. tumefaciens were affected by inoculation time and artificial wounding. Transformation frequency was increased over 50% by combining artificial wounding with 120 s of inoculation treatment. Confirmation for the transformation of regenerated shoots was carried out by histochemical ${\beta}$-glucuronidase assay and polymerase chain reaction analysis using npt II primer.

• The Korean Journal of Pesticide Science
• /
• v.9 no.4
• /
• pp.429-436
• /
• 2005

As Sclerotinia sclerotiorum causing cucumber sclerotinia rot was the fastest in the mycelial growth at $25^{\circ}C$, its pathogenicity was strong at the same temperature among several temperatures. All the isolates of Sclerotinia sclerotiorum showed a strong pathogenicity against cucumber fruits, which was confirmed by a disk assay and a wound assay. A wound assay was superior to a disk assay to develop the assay system for assessing the fungicidal activity of several fungicides against Sclerotinia sclerotiorum. In a disk assay, it was very difficult to assess the fungicidal activity, because the pathogenicity of isolates used in the experiment was very strong. At 500 and $3.0{\mu}g/mL$, the activity of dichloflouanid and the mixture of carbendazim and diethofencarb against cucumber sclerotinia rot was 14.3 and 42.3%, respectively, by using a disk assay. However, at same concentration two fungicides showed the high controlling activity as 100 and 92.5%, through a wound assay in a laboratory. Also, the activity of two fungicides was good against cucumber sclerotinia rot in the greenhouse where cucumber plants were cultivated in the field, showing the control value as 91.1 and 82.9% at 100 and $825{\mu}g/mL$, respectively. All the isolates of Sclerotinia sclerotiorum from cucumber fruits sampled in the polyvinyl house were subjected to monitoring for the resistance to 7 fungicides. The $EC_{50}$ value of 7 fungicides was as follows: fenhexamid; $0.13{\mu}g/mL$, procymidon and iprodione; 0.18 and $0.24{\mu}g/mL$, carbendazim and the mixture of carbendazim and diethofencarb; 0.13과 $0.05{\mu}g/mL$, iminoctadine and dichlofluanid; 1.94 and $8.95{\mu}g/mL$. Ultimately it was not found that resistant isolates of Sclerotinia sclerotiorum were appeared in the field.

• The Korean Journal of Pesticide Science
• /
• v.18 no.2
• /
• pp.115-121
• /
• 2014

This study was performed to investigate the effect of conidial density, wetness period and temperature on conidial germination, appressoria formation and disease incidence. While there was not significantly correlated between conidial density and temperature, and conidial germination and appressoria formation, there was a significant correlation between those factors and disease incidence. The longer wetness period was, the higher the ratio of conidial germination, appressoria formation and the disease incidence was. The optimum conidial density, temperature and wetness period was $1{\times}10^6$ conidia $mL^{-1}$, $30^{\circ}C$ and 5 days, respectively. In case the wetness period was more than 5 days, the typical symptom was not found on pepper fruits because of the overgrowth of mycelia. Using this fruit assay method, which the pepper anthracnose pathogens were inoculated by spraying spore suspension on non-wounded or wounded pepper fruits, control effect of three fungicides were evaluated against pepper anthracnose by the protective and/or the curative application. Propineb showed high protective control activity, while it showed curative control activity on unwounded fruits, but did not showed curative control activity on wounded fruits. Tebuconazole, one of curative fungicide, showed higher control activity in non-wound inoculation than wound inoculation. Trifloxystrobin, one of strobilurin group, showed high both protective and control activity against anthracnose. In conclusion, we supposed that the newly developed in vitro pepper fruit assay can be used to evaluate antifungal activity of control agents against pepper anthracnose.

• Horticultural Science & Technology
• /
• v.31 no.3
• /
• pp.366-370
• /
• 2013

This experiment was carried out to establish the screening methods for the selection of Zantedeschia aethiopica cultivars resistant to calla lily soft rot caused by Pectobacterium carotovorum subsp. carotovorum. A center of leaf and petiole tissues of four Z. aethiopica cultivars were wounded and inoculated with three different inoculum concentrations, $1{\times}10^7cfu/mL$, $1{\times}10^8cfu/mL$, and $1{\times}10^9cfu/mL$, of EccNHRI-21 isolate. And they were evaluated at 4, 18, and 26 hours after inoculation. The lesion of maceration was developed well in the leaf tissues inoculated with $1{\times}10^9cfu/mL$ concentration. And evaluation of resistance in 18 hours after inoculation was correlated with field resistance positively. Using this method, ten Z. aethiopica commercial cultivars and four wild types were screened. 'Crowbrough' and 'White Cutie' were selected as highly resistant genotypes and 'Mont Blanc' and 'Silky White' as resistant genotypes. 'Wedding March' and 'Kiwi Blush' were evaluated as moderate resistant and the others including 'Childsiana' were susceptible. And all of four wild types were evaluated as more than moderate resistant. In spite of control through cultural, biological and chemical methods, the use of resistant cultivars is most efficient to overcome calla lily soft rot. This newly developed screening method was helpful for breeding new varieties resistant to calla lily soft rot.

• Research in Plant Disease
• /
• v.16 no.2
• /
• pp.148-152
• /
• 2010

To establish the efficient screening method for resistance of radish to F. oxysporum f. sp. raphani, we investigated the development of Fusarium wilt of two radish cultivars, 'Songbaek' (susceptible) and 'Tokwang' (moderately resistant), according to several conditions such as inoculation methods, inoculum concentrations, and dipping periods of radish roots in spore suspension. By infected soil and soil-drenching inoculation methods, Fusarium wilt did not occur on the seedlings of both cultivars. In root dipping inoculation method using cut or non-cut roots of radish plants, the cut roots were easily infected by the pathogen than non-cut roots. And the disease development of two cultivars represented significant difference in non-cut root method. On the other hand, disease severity of Fusarium wilt on radish seedlings according to inoculum concentration increased in a dose-dependant manner, regardless of dipping periods. Using screening method established from the results, the 41 commercial radish cultivars were evaluated the degree of resistance to F. oxysporum f. sp. raphani. Among them, 6 radish cultivars were resistant, 22 cultivars were moderately resistant, and 13 cultivars were susceptible to Fusarium wilt.

• Research in Plant Disease
• /
• v.21 no.4
• /
• pp.290-296
• /
• 2015

This study was conducted to establish an efficient screening system for resistant tomato to bacterial wilt caused by Ralstonia solanacearum. Under several conditions such as inoculation methods, growth stages of tomato seedlings, inoculum concentrations, and incubating temperatures after inoculation, development of bacterial wilt on nine resistant or susceptible cultivars of tomato was investigated. To inoculate by drenching the non-cut roots with the bacterial suspension was better to distinguish resistance and susceptibility of tomato cultivars than by drenching the cut roots using scalpel. And 'Hawaii7996' a resistant tomato to R. solanacearum showed high resistance at all the tested conditions including growth stages (3-, 6-, 8-, 10-leaf stages), inoculum concentrations ($OD_{600}=0.1-0.4$) and incubation temperatures (25, 30, $35^{\circ}C$). On the other hands, susceptible cultivars represented disease index of 3.7 and 3.9 at 6- and 8-leaf stages, respectively. At 3- and 10-leaf stages, the cultivars demonstrated lower disease severity of 2.1 and 0.5, respectively, than at 6- and 8-leaf stages. When the inoculated seedlings were incubated in growth chambers of 25, 30 and $35^{\circ}C$, disease severity of susceptible cultivars was significantly greater at 30 and $35^{\circ}C$ than at $25^{\circ}C$. In addition, the level of resistance of the tomato cultivars was not significantly affected by inoculum concentrations of $OD_{600}=0.1-0.4$. On the basis of the results, we suggest an efficient screening method to measure resistance level of tomato cultivars to bacterial wilt. The eight-leaf stage seedlings transplanted 7 days before inoculation, are inoculated with R. solanacearum by drenching the non-cut roots with a bacterial suspensions ($OD_{600}=0.4$) to give inoculum volume of 50 ml/soil l. The inoculated plants are incubated in a growth room at $30^{\circ}C$ for 12-13 days with 12-hour light a day.

• Research in Plant Disease
• /
• v.19 no.2
• /
• pp.95-101
• /
• 2013

Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is one of the most serious diseases of crucifers world-wide. To establish the efficient screening method for resistant cabbage to Xcc, different inoculation methods, inoculation positions, growth stages of seedlings, and incubation temperatures after inoculation were investigated with the seven cabbage cultivars showing different resistance degrees to the pathogen. Clipping with mouse-tooth forceps was better inoculation method than piercing with 18 pins or cutting with scissors to distinguish the level of resistance and susceptibility. In inoculation using mouth-tooth forceps, clipping the edges of the leaves near veins is more effective than injuring the veins of the leaves directly. In addition, the inoculated plants kept at $22^{\circ}C$ showed more clear resistant and susceptible responses than those kept at 26 or $30^{\circ}C$. On the basis of the results, we suggest that an efficient screening method for resistance of cabbage cultivars to black rot is to clip the edges of the leaves near veins of the four-week-old seedlings with mouth-tooth forceps dipped in a suspension of Xcc at a concentration of $7{\times}10^7$ cfu/ml and incubate the inoculated plants in a growth room at $22^{\circ}C$ with 12-hr light a day.

• Korean journal of applied entomology
• /
• v.12 no.1
• /
• pp.23-27
• /
• 1973

In an effort to find effective inoculation method of Fusarium nivale, this experiment was conducted. The results obtained are summarized as follows: (1) Distilled water-spore suspension of this fungus was inoculated on rice seedling and the result showed that negligible disease symptoms were observed when the inoculated plants were placed in a moist chamber for one day, whereas considerable symptoms were indicated when kept for two days. (2) After giving physical wounds by wind or wooden stick to the rice seedling, distilled water-spore suspenion was sprayed on them and considerable diseased spots were formed. (3) Sufficient disease occurrence was due to the addition of $1\%$ rice leaf extract, glucose, polypeptone, and yeast extract solution to the spore suspension. (4) In distilled water, spore germination was poor, while in nutrient added solution good germination rate as well as anastomosis was found. (5) A new rice variety Tong-il turned out to be more susceptible to Fusarium nivale than Pung-kwang.

• Pediatric Infection and Vaccine
• /
• v.20 no.1
• /
• pp.9-16
• /
• 2013

Purpose : This study aims to investigate preexposure prophylaxis and postexposure prophylaxis of rabies that the National Medical Center (NMC) handled and to check whether appropriate measures were performed according to the recent domestic and overseas guidelines after animal bites. Methods : This study surveyed 41 people who were 18 years or under and received preexposure and postexposure prophylaxis of rabies at the NMC from November 2006 to December 2011. Their medical records were reviewed for their age, gender, the reason for preexposure prophylaxis, the body sites of animal bite, the kind of the animal that bit children, the region where the biting occurred and rabies vaccination and inoculation of immunoglobulin. Results : Eleven children took rabies vaccination for preexposure prophylaxis and 30 children received post exposure prophylaxis of rabies. Of patients who were bitten by unvaccinated animals including wild animals or by animals which were not certain to be vaccinated, 50% (13 of 26 children) received postexposure prophylaxis, while 75% (3 of 4 children) of patients who were bitten by vaccinated animals received postexposure prophylaxis of rabies. Ten of 30 bitten patients knew whether or not the biting animals had received rabies vaccination. Of them, four people (40%) were bitten by animals which had received rabies vaccination. Conclusion : To prevent the occurrence of rabies, people and health care providers need to correctly understand latest guideline for rabies preexposure and postexposure prophylaxis and the information for bitten patient, biting animal and area at bitten by animal should be accurately recorded.

• Research in Plant Disease
• /
• v.22 no.3
• /
• pp.152-157
• /
• 2016

Root-dipping inoculation method has been used to investigate resistance of radish plants to Fusarium wilt. However, the method requires a lot of labor and time because of complicate procedure. This study was conducted to establish a simple and effective mass-screening method for resistant radish to Fusarium wilt. Radish seedlings of susceptible and resistant cultivars were used to investigate wounding method by scalpel, inoculum concentration, and pathogen-inoculated growth stage of seedlings. We established an efficient mass-screening method based on our results as following: Roots of 14-day-old seedlings of radish are cut with a scalpel at a $90^{\circ}$ angle to a 2 cm-depth at a 1 cm-distance from main stem and then inoculated by pouring with a 10 ml-aliquot of a fungal spore suspension ($1.0{\times}10^7conidia/ml$) on soil. The inoculated plants are cultivated in a growth room at $25^{\circ}C$ for about 4 weeks with 12-hour light a day. The proposed screening method enables to effectively select resistant from mass radish plants cultivars to Fusarium wilt.