• Mycobiology
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• v.33 no.3
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• pp.131-136
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• 2005

Infection structures were observed at the penetration sites on the leaves of cucumber plants inoculated with Colletotrichum orbiculare using a fluorescence microscope. The cucumber plants were previously drenched with suspension of bacterial strains Pseudomonas putida or Micrococcus luteus. The plants pre-inoculated with both bacterial strains were resistant against anthracnose after inoculation with C. orbiculare. To investigate the resistance mechanism by both bacterial strains, the surface of infected leaves was observed at the different time after challenge inoculation. At 3 days after inoculation there were no differences in the germination and appressorium formation of conidia of C. orbiculare as well as in the callose formation of the plants between both bacteria pre-inoculated and non-treated. At 5 days, the germination and appressorium formation of the fungal conidia were, however, significantly decreased on the leaves of plants pre-inoculated with M. luteus at the concentration with $1.0{\times}10^7\;cfu/ml$. Furthermore, callose formation of plants cells at the penetration sites was apparently increased. In contrast, there were no defense reactions of the plants at the concentration with $1.0{\times}10^6\;cfu/ml$ of M. luteus. Similarly, inoculation P. putida caused no plant resistance at the low concentration, whereas increase of callose formation was observed at the higher concentration. The results of this study suggest that the resistant mechanisms might be differently expressed by the concentration of pre-treatment with bacterial suspension.

• Journal of Plant Biotechnology
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• v.43 no.2
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• pp.240-247
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• 2016

In this study, routinely used transformation method, which includes transferring explants onto co-cultivation medium after inoculating them with bacterial solution for a while, was compared with 3 different inoculation methods. In every 3 methods, hypocotyl explants excised from 7-day-old sterile flax seedlings having cotyledon leaves and no root system dried under air flow in sterile cabin for 35 min were inoculated with different volumes of bacterial solution at different inoculation periods. GV2260 line of Agrobacterium tumefaciens having 'pBIN 19' plasmid containing npt II (neomycin phosphotransferase II) gene and GUS reporter gene was used in transformation studies. After inoculation, hypocotyl segments of seedlings (0.5 cm in length) - were excised and left to co-cultivation for 2 days. Then, explants were transferred to regeneration medium supplemented with different antibiotics. The presence of npt-II and GUS genes in transformants was confirmed by PCR and GUS analysis. The highest results in all characters examined in all cultivars were obtained from the 2 inoculation method in which hypocotyls excised from seedlings inoculated with $500{\mu}l$ of bacterial solution after drying in sterile cabin for 35 min were used.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.85-91
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• 2003

Pre-treatment with DL-3-aminobutyric acid (BABA) in the cucumber plants caused the decrease of disease severity after inoculation with anthracnose pathogen Colletotrichum orbiculare. In this study, ultrastructures of the vascular bundle and the infection structures in the leaves of BABA-treated as well as untreated cucumber plants were observed after inoculation with the anthracnose pathogen by electron microscopy. The ultrastructures of vascular bundle in the leaves of BABA-treated plants were similar to those of the untreated plants except plasmodesmata. In the BABA-treated plants, the plasmodesmata were more numerous than in the untreated plants, suggesting that the BABA treatment may cause the active transfer of metabolites through the vascular bundle. In the leaves of untreated plants, the fungal hyphae were spread widely in the plant tissues at 5 days after pathogen inoculation. Most cellular organelles in the hyphae were intact, indicating a compatible interaction between the plant and the parasite. In contrast, in the leaves of BABA pre-treated plants the growth of most hyphae was restricted to the epidermal cell layer at 5 days after inoculation. Most hyphae cytoplasm and nucleoplasm was electron dense or the intracellular organelles were degenerated. The cell walls of some plant cells became thick at the site adjacent to the intercellular hyphae, indicating a mechanical defense reaction of the plant cells against the fungal attack. Furthermore, hypersensitive reaction (HR) of the epidermal cells was often observed, in which the intracellular hyphae were degenerated. Based on these results it is suggested that BABA causes the enhancement of defense mechanisms in the cucumber plants such as cell wall apposition or HR against the invasion of C. orbiculare.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.87-94
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• 2009

This study was conducted to develop an automation system of inoculation processing of a lily callus. The results are summarized as followings: The end-effector was manufactured as suction and machine type. And these end-effectors can separate the callus from the mediums and divide the separated callus and then inoculate the divided callus to new mediums. Using the machine type end-effect0r, the results of the experiment showed the success rate in the division process was 100% while the separation and inoculation process was 92%. To develop the automation controller of inoculation process, the system was developed to control an external device and the manipulator. The data communication program between a robot and a personal computer was also developed using CAsyncsocket and Ethernet Interface.

• 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.

• The Plant Pathology Journal
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• v.37 no.5
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• pp.455-464
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• 2021

Forty-eight spring barley genotypes were evaluated for deoxynivalenol (DON) concentration under natural infection across 5 years at Harrington, Prince Edward Island. These genotypes were also evaluated for Fusarium head blight (FHB) severity and DON concentration under field nurseries with artificial inoculation of Fusarium graminearum by the grain spawn method across 2 years at Ottawa, Ontario, and one year at Hangzhou, China. Additionally, these genotypes were also evaluated for FHB severity under greenhouse conditions with artificial inoculation of F. graminearum by conidial suspension spray method across 3 years at Ottawa, Ontario. The objective of the study was to investigate if reactions of barley genotypes to artificial FHB inoculation correlate with reactions to natural FHB infection. DON concentration under natural infection was positively correlated with DON concentration (r = 0.47, P < 0.01) and FHB incidence (r = 0.56, P < 0.01) in the artificially inoculated nursery with grain spawn method. Therefore, the grain spawn method can be used to effectively screen for low DON. FHB severity, generated from greenhouse spray, however, was not correlated with DON concentration (r = 0.12, P > 0.05) under natural infection and it was not correlated with DON concentration (r = -0.23, P > 0.05) and FHB incidence (r = 0.19, P > 0.05) in the artificially inoculated nursery with grain spawn method. FHB severity, DON concentration, and yield were affected by year, genotype, and the genotype × year interaction. The effectiveness of greenhouse spray inoculation for indirect selection for low DON concentration requires further studies. Nine of the 48 genotypes were found to contain low DON under natural infection. Island barley had low DON and also had high yield.

• Korean journal of applied entomology
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• v.58 no.1
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• pp.49-54
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• 2019

Clover cyst nematode, Heterodera trifolii are one of the major pests that damage Chinese cabbage in high land cultivation area and have recently been distributed in Korea. This study was conducted to investigate the effect of temperature and inoculation density on the proliferation of clover cyst nematode. The clover cyst nematode was proliferated at $15-30^{\circ}C$ and the egg, female adult and cyst number was the highest at $20^{\circ}C$. As the inoculation density increased, the number of female cyst nematodes increased with the inoculation density and when 16 eggs were inoculated per gram of soil, the amount of growth, number of egg and cyst was the highest. Number of females and eggs were formed more in cabbage than in kale regardless of inoculation density. Chinese cabbage was a favorable host for clover cyst nematode growth than kale.

• Mycobiology
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• v.32 no.4
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• pp.173-178
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• 2004

Fifteen Rhizobium spp. from nodules of 6 common pulses collected from 6 districts of Assam were studied for their infectivity, intrinsic antibiotic resistance, nitrogenase activity and effect of dual inoculation with two native Arbuscular Mycorrhizal Fungi viz. Glomus mosseae(GM) and Gigaspora gilmarie(GG). Out of the 15 isolates 9 were found nodulation positive and 6 of them(AR1, BR8, BR12, AR10, UR10 & GR21) were subjected to intrinsic antibiotic sensitivity test of which AR1 showed resistance against all the 9 test antibiotics. Isolates AR1 and GR21 showed the highest(4.25 mole, $gm^{-1}hour^{-1}$) and the lowest(1.05 mole, $gm^{-1}hour^{-1}$) nitrogenase activity respectively. In Most Probable Number count, the maximum Rhizobium population $5.8{\times}10^5$, was found in both Blackgram and Greengram variety of pulses. The maximum dry weight of nodules(3.14 g), dry weight of shoot(10.08 g), nitrogen content(7.68 mg, $plant^{-1}$), chlorophyll content(1.89 mg, $g^{-1}$), phosphorus content of shoot(6.17 mg, $g^{-1}$) and yield(535.67 kg, $Ha^{-1}$) were found when AR1 dually inoculated with GM in Blackgram.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.140-144
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• 2017

This study was conducted to investigate the effect of microbial inoculation as additive consisting of novel lactic acid bacteria on quality and fermentation characterization of Miscanthus sinnensis silages. The contents of crude protein, acid detergent fiber, neutral detergent fiber in treatments of additive of lactic acid bacteria (ALAB) inoculation had similar to control. pH of Miscanthus sinnensis (MS) silage in treatments of ALAB inoculation significantly decreased as compared to control (p<0.05). The content of lactic acid in in treatments of ALAB inoculation significantly increased (p<0.05), but the content of acetic acid in treatments of ALAB inoculation decreased. In addition, number of lactic acid bacteria in treatments of ALAB inoculation significantly increased as compared to control (p<0.05). Therefor, we suggest that MS silage improved by inoculation of additive consisting of novel lactic acid bacteria.

• 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.