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

• Horticultural Science & Technology
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• v.31 no.1
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• pp.110-116
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• 2013

This study was carried out to establish the simple mass-screening methods for resistant tomato to Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici (FOL). Root dip inoculation method has been used in many studies on the resistance of tomato to disease. On the other hand, in mass-screening for resistant tomato to Fusarium wilt, the inoculation method is time-consuming and laborious procedure. Disease development of two FOL isolates on two cultivars of tomato according to inoculation method including root dip, tip and scalpel methods were investigated. In compatible interaction, tomato seedlings of each cultivar inoculated by tip method showed the lower and more variable disease severities than by root dip method. Whereas the seedlings by scalpel method represented clear resistant and susceptible responses to Fusarium wilt as root dip method. The resistance degree of each cultivar inoculated with FOL isolates by scalpel method was hardly affected by the tested incubation temperature and inoculum concentration. On the basis of the results, we suggest scalpel inoculation method as an efficient mass-screening method for resistant of tomato cultivars to Fusarium wilt. Roots of tomato seedlings at two-leaf stage grown in plastic cell tray were injured with scalpel and then spore suspension (more than $1{\times}10^7\;conidia{\cdot}mL^{-1}$) of FOL was poured directly on the roots. The infected plants were cultivated in a growth room at $25-30^{\circ}C$ for 4 weeks with 12-hours light a day.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.1002-1007
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• 2010

The study was performed to investigate the influence on growth and development of grape-cuttings by arbuscular mycorrhizal (AM) fungi inoculation, AM colonization rate, and the phenomena of mycorrhizal association. Among the grape-cuttings, 'Kyoho' and 'Tamnara' cultivars inoculated with AM fungi showed significantly increase of leaf area, leaf number, total root length and root surface area than non-infected ones. But 'Cambell Early' did not showed any significant difference in total root length and root surface area even after the inoculation. The AM colonization rates in mycorrhizal inoculation treatment were 22.5-32.5% in total average after 8weeks, and were 29.6%, 28.8%, and 48.8% for 'Cambell Early', 'Tamnara', and 'Kyoho' respectively after 12weeks. The AM colonization rate marked very low level in non-colonization control plot.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.5
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• pp.355-360
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• 2003

The responses of six mungbean [Vigna radiata (L.) Wilczek] varieties to Rhizobium inoculation on number and dry weight of nodules, nitrogenase activity of root nodule bacteria, dry weight of shoot and root, nitrogen content, and uptake by shoot were investigated. The mungbean varieties were BARI Mung-2, BARI Mung-3, BARI Mung-4, BARI Mung-5, BINA Moog-2, and BU Mung-1. Two-third seeds of each variety were inoculated with Rhizobium inoculant and the remaining one-third seeds were kept uninoculated. Rhizobium strains TAL 169 and TAL 441 were used for inoculation of seeds. Inoculation of seeds with Rhizobium strains significantly increased nodulation, nitrogenases activity, dry matter production, nitrogen content, and uptake by shoot of the crop compared to uninoculated control. There was positive correlation among the number and dry weight of nodules, nitrogenase activity, dry weight of shoot and root, nitrogen content, and uptake by shoot of the crop. It was concluded that BARI Mung-4 in association with Rhizobium strain TAL 169 performed best in recording nodulation, nitrogenase activity, dry matter production, and nitrogen uptake by shoot of mungbean.

• Research in Plant Disease
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• v.21 no.3
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• pp.201-207
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• 2015

This study was conducted to establish a simple mass-screening method for resistant melon to Fusarium wilt caused by Fusarium oxysporum f. sp. melonis (FOM). Root-dipping inoculation method has been used to investigate resistance of melon plants to Fusarium wilt. However, the inoculation method requires a lot of labor and time because of complicate procedure. To develop a simple screening method on melon Fusarium wilt, occurrence of Fusarium wilt on susceptible and resistant cultivars of melon according to inoculation method including root-dipping, soil-drenching, tip, and scalpel methods was investigated. Scalpel and tip methods showed more clear resistant and susceptible responses in the melon cultivars than root-dipping inoculation method, but tip method represented slightly variable disease severity. In contrast, in the case of soil-drenching inoculation method, disease severity of the susceptible cultivars was very low. Thus we selected scalpel method as inoculation method of a simple screening method for melon Fusarium wilt. By using the scalpel inoculation method, resistance degrees of the cultivars according to incubation temperature after inoculation (25 and $30^{\circ}C$) and inoculum concentration ($1{\times}10^6$ and $1{\times}10^7conidia/ml$) were measured. The resistance or susceptibility of the cultivars was hardly affected by all the tested conditions. To look into the effectiveness of scalpel inoculation methods, resistance of 22 commercial melon cultivars to FOM was compare with root-dipping inoculation method. When the melon cultivars were inoculated by scalpel method, resistance responses of all the tested cultivars were clearly distinguished as by root-dipping method. Taken together, we suggest that an efficient simple mass-screening method for resistant melon plant to Fusarium wilt is to sow the seeds of melon in a pot (70 ml of soil) and to grow the seedlings in a greenhouse ($25{\pm}5^{\circ}C$) for 7 days, to cut the root of seedlings with a scalpel and then pour a 10 ml-aliquot of the spore suspension of $1{\times}10^6conidia/ml$ on soil. The infected plants were cultivated in a growth room at 25 to $30^{\circ}C$ for about 3 weeks with 12-hr light a day.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.1
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• pp.27-31
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• 2002

Three kinds of inoculation methods, capillary, root cutting and dipping were compared for an efficient way to screening the resistant tobacco variety against bacterial wilt, Ralstonia solanacearum. The pricking a capillary tube contained the pathogenic bacterial suspension(10$^{7}$ cfu/$m\ell$) to an axillary bud of each tobacco plant showed different resistance well between varieties. The less period was required in inoculating work and in disease development for the inoculation method used with capillary tube than for two other inoculation methods tested also.

• Research in Plant Disease
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• v.23 no.2
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• pp.168-176
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• 2017

Root-dipping inoculation method has been widely used to determine the resistance of watermelon to Fusarium oxysporum f. sp. niveum causing Fusarium wilt. Although this method leads to the precise results of plant disease responses, more rapid and efficient assay methods have been still required because the root-dipping inoculation method is labor-intensive and time-consuming. In this study, we established a simple and effective bioassay method based on the comparison of various inoculation methods and growth conditions. To develop the system, the occurrence of Fusarium wilt on four resistant and susceptible cultivars was investigated by four different inoculation methods, root-dipping, scalpel, tip and soil-drenching methods. Of these inoculation methods, scalpel method resulted in clear plant disease resistance responses with the simplicity. With the use of scalpel method, we also explored the disease development of the cultivars depending on inoculum concentration, growth stage of seedlings, and incubation temperature after inoculation. Furthermore, we found that the resistance degrees of 23 cultivars derived by scalpel inoculation method were similar to the results by root-dipping method established previously.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.113-120
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• 2009

Microscopic study of chili pepper (Capsicum annuum L.) infected with Phytophthora capsici, causing Phytophthora blight of chili pepper, was conducted to compare histological and cytological characteristics in the root and stem of susceptible (C. annuum cv. Bugang) and resistant (C. annuum cv. CM334) pepper cultivars. The susceptible pepper roots and stems were extensively penetrated and invaded by the pathogen initially into epidermal cells and later cortical and vascular cells. Host cell walls adjacent to and invaded by the infecting hyphae were partially dissolved and structurally loosened with fine fibrillar materials probably by cell wall-degrading enzymes of the pathogen. In the resistant pepper, the pathogen remained on root epidermal surface at one day after inoculation, embedded and captured in root exudation materials composed of proteins and polysaccharides. Also the pathogen appeared to be blocked in its progression at the early infection stages by thickened middle lamellae. At 3 days after inoculation, the oomycete hyphae were still confined to epidermal cells of the root and at most outer peripheral cortical cells of the stem, resulting from their invasion blocked by wound periderms formed underneath the infection sites and/or cell wall appositions bounding the hyphal protrusions. All of these aspects suggest that limitation of disease development in the resistant pepper may be due to the inhibition of the pathogen penetration, infection, invasion, and colonization by the defense structures such as root exudation materials, thickened middle lamellae, wound peridems and cell wall appositions.

• Horticultural Science & Technology
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• v.35 no.1
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• pp.11-20
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• 2017

The objective of this study was to determine whether inoculation with Bacillus licheniformis MH48 as a plant growth-promoting rhizobacterium (PGPR) could promote nutrient uptake of seedlings of the ornamental plant Camellia japonica in the Saemangeum reclaimed coastal land in Korea. B. licheniformis MH48 inoculation increased total nitrogen and phosphorus content in soils by 2.2 and 20.0 fold, respectively, compared to those without bacterial inoculation. In addition, B. licheniformis MH48 produced auxin, which promoted the formation of lateral roots and root hairs, decreased production of growth-inhibiting ethylene, and alleviated salt stress. Total nitrogen and phosphorus uptake of seedlings subjected to bacterial inoculation was 2.3 and 3.6 fold higher, respectively, than the control. However, B. licheniformis MH48 inoculation had no significant effect on the growth of seedlings. Our results suggest that inoculation with B. licheniformis MH48 can be used as a PGPR bio - enhancer to stimulate fine root development, promote nutrient uptake and alleviate salt stress in ornamental plant seedlings grown in the high-salinity conditions of reclaimed coastal land.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.527-533
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• 2006

The response of chickpea (Cicer arietinum L.) to dual inoculation with Rhizobium (R) and arbuscular mycorrhiza (AM), nitrogen (N) and phosphorus (P) was studied on spore abundance and colonization of AM, nodulation, growth, yield attributes and yield. In all the parameters of the crop the performance of Rhizobium inoculant alone was superior to control. Dual inoculation with Rhizobium and AM in presence of P performed the best in recording number of spore $100g^{-1}$ rhizosphere soil and root colonization, number and dry weight of nodule, dry weights of shoot and root, number of pod $plant^{-1}$, number of seed $pod^{-1}$, seed and stover yields of chickpea. The maximum seed yield of 3.33 g $plant^{-1}$ was obtained by inoculating chickpea plants with Rhizobium and AM in association with P. From the view point of nodulation, growth, yield attributes and yield of chickpea, dual inoculation with Rhizobium and AM along with P was considered to be the balanced combination of nutrients for achieving the highest output from cultivation of chickpea in Shallow Red Brown Terrace Soil of Bangladesh.