• The Plant Pathology Journal
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• 제39권2호
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• pp.220-227
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• 2023

Rose crown gall caused by Agrobacterium tumefaciens is a major disease that damages the production of cutroses in Korea. The effective prevention methods for this disease include the use of resistant varieties. This study was conducted to evaluate the resistance of 58 Korean cultivars and six foreign cultivars to crown gall disease with nodal explants in vitro. Among 180 A. tumefaciens strains, pathogenic strain RC12 was selected as an inoculant strain. The strain RC12 was identified based on characteristics of some selective media, pathogenicity test, and polymerase chain reaction analysis. Forty rose cultivars formed tumors on explants inoculated with A. tumefaciens RC12. However, 24 cultivars, including 22 Korean cultivars and 2 foreign cultivars, showed resistance to A. tumefaciens RC12 without forming any tumors. Six cultivars with tumor formation rates of over 30% formed initial tumors within 23 days after inoculation. Six cultivars with low tumor formation rates of around 5% formed initial tumors after 28 days of inoculation. It was found that gall formation rate was highly correlated with the initial gall formation period. Thus, the relationship between the period of gall formation and the rate of gall formation could be useful for assessing resistance to crown gall disease. In vitro inoculation methods could be used to evaluate resistance of cut-rose cultivars to crown gall diseases.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.188-188
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• 2022

Our previous study identified a resistance locus to Phytophthora sojae (isolate 2457) in an interval of 3.8-4.7 Mbp on chromosome 3 via genetic mapping using a 'Daepung'×'Daewon' recombinant inbred population. Since differential gene expression between Daepung (susceptible) and Daewon (resistant) after inoculation of P. sojae is unknown, RNA sequencing was carried out to compare transcriptomic changes between the two genotypes following inoculation with P. sojae isolate 2457. The two varieties were inoculated using hypocotyl inoculation at the VC stage and stem tissue of 1 cm above and below of the inoculated site were sampled at 0, 6, 12 hours after inoculation (hai), respectively. Differentially expressed genes (DEGs) under same cultivar in different time point and Daepung vs. Daewon in same time point were investigated. In comparison of Daepung vs. Daewon at 12 hai, a total of 3,513 DEGs were identified, including two nucleotide-binding site-leucine rich repeat (NBS-LRR) genes (Glyma.03g034800 and Glyma.03g034900) that are located in the previously reported resistance locus on chromosome 3. In addition, 14,966 DEGs were detected between 0 vs. 6 hai, containing one of candidate genes (Glyma.03g035300). This gene was upregulated by up to 4-fold in Daewon and Daepung. Additional results will be further discussed in the presentation. This study will provide valuable information for soybean crop improvement.

• The Plant Pathology Journal
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• 제19권5호
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• pp.257-259
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• 2003

This report described a simple, inexpensive, faster, and effective graft inoculation method for the artificial transmission of Mungbean yellow mosaic virus (MYMV). Success of grafting and disease transmission was 100％ in this method. Screening of mungbean germplasm using this method will prevent the chance of escape infection, probably as a consequence of non-preference mechanism and loss of vector infectivity. The grafting method described here is applicable to both screenhouse and field trials.

• KSBB Journal
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• 제13권1호
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• pp.31-37
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• 1998

A simple method for the in vivo production of third-stage infective juveniles(IJs) of Steinernema glaseri was developed. Using Galleria mellonella larvae, only IJs can be rapidly generated inadequate quantities for field application. The nematode inoculation concentration and incubation temperature were critically important. The most effective temperature for infectivity of Steinernema glaseri IJs to Galleria mellonella larvae was 33$^\circ C$. However, the total number of menatodes harvested at 25$^\circ C$ about 66,000 IJs per larva was significantly greater than those at other temperatures. The optimal inoculation number of nematodes was 60 to 80 nematodes per host larva. The higher nematode inoculation concentration of 100 IJs per larva caused a rapid decrease in the total number of IJs harvested. As the inoculation medium pH increased, the number of IJs harvested increased and reached about 110,000 IJs per larva at pH 9.0. The pathogenicity of IJs decreased y increasing the salt concentration in the medium.

• 한국식물병리학회지
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• 제14권3호
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• pp.247-252
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• 1998

A series of greenhouse test was conducted to evaluate infection of Calonectria ilicicola on soybean plants of different ages at time of inoculation. Lesion length and number of perithecia were determined on cultivars Braxton, Deltapine 726, and Riverside 699 that were 10∼40 days old and 4-10 days old at time of inoculation. Quadratic and linear relationships were described between plant age at inoculation and lesion length or perithecia production in greenhouse studies. Soybean seedlings exhibited low susceptibility to C. ilicicola regardless of cultivar susceptibility. On 8- or 1-0-days-old Braxton, lesion lenght and perithecia numbers were reduced. Lesion lengths were longest on plants 30 days old whereas perithecia production was greatest on plants 20∼30 days old at time of inoculation. Differences in lesion length and perithecia production that were observed on young plants (4∼10 days old) were similar to relative levels of susceptibility in soybean cultivars in greenhouse and field tests, suggesting that reaction to C. ilicicola in soybean cultivars may be determined early in plant development.

• Mycobiology
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• 제35권4호
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• pp.238-240
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• 2007

Anthracnose symptoms often occurred on fruits of Asian pear trees grown in Anseong, Naju, Seonghwan and Pyeongtaek in Korea during the harvesting period from 2000 to 2005. A total of 28 isolates of Colletotrichum sp. were obtained from the anthracnose symptoms. All the isolates were identified as Colletotrichum acutatum based on their morphological and cultural characteristics. Four isolates of the fungus were tested for pathogenicity to fruits of Asian pear tree by artificial inoculation. All the isolates induced anthracnose symptoms on the fruits by wound inoculation but not by unwound inoculation. The anthracnose symptoms induced by artificial inoculation were similar to those observed in the orchard. This is the first report of anthracnose of Asian pear tree caused by Colletotrichum acutatum.

• Mycobiology
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• 제37권1호
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• pp.72-76
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• 2009

To investigate the growth response of various crop species to mycorrhizal inoculation, arbuscular mycorrhizal fungi were applied to Glycine max, Vigna angularis, Senna tora, Hordeum vulgare var. hexastichon. Zea mays, Sorghum bicolor, Allium tuberosum, Solanum melongena, and Capsicum annuum. The biomass of the inoculated crops was measured every two weeks for the 12-week growth period. By measuring biomass, we calculated the mycorrhizal responsiveness of the nine crop species. Among the nine crop species, four species showed a significant response to mycorrhizal inoculation. The shoot biomasses of V. angularis, C. annuum, A. tuberosum, and S. tora significantly increased with mycorrhizal inoculation.

• 한국미생물·생명공학회지
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• 제21권2호
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• pp.95-100
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• 1993

Effect of dual inoculation with vesicular-arbuscular(VA) mycorrhizal fungi, Glomus mosseae, and Rhizobium meliloti R455 on growth, nodulation, and nitrogenase activity of alfalfa (Medicago sativa L. cv. Vernal) were examined in pot experiment. After 63 days growth, shoot length, number of leaf, and leaf size of alfalfa were increased as as result of dual inoculation with Glomus mosseae and Rhizobium meliloti. Total dry weight of alfalfa plant was increased 1.4 times compared to single inoculation with Rhizobium meliloti. Nodule number and mean fresh weight of nodule per plant were also increased due to the mycorrhizal infection.

• Journal of Applied Biological Chemistry
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• 제57권2호
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• pp.153-157
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• 2014

Plant-growth-promoting rhizobacteria can affect plant growth by various direct and indirect mechanisms. This study was conducted to determine the ability of some rhizobacterial strains to enhance the seed germination of Lactuca sativa (lettuce) and Raphanus sativus (radish). Seeds were inoculated using a spore suspension ($1{\times}10^7cfumL^{-1}$) and incubated in a growth chamber at $28^{\circ}C$ under dark conditions and 65% RH. Azotobacter chroococcum and LAP mix inoculation increased the plumule length of L. sativa by 1.3, 0.8, and 0.7 cm, respectively, in comparison to the uninoculated control. Pseudomonas putida showed an increase of only 0.6 cm in plumule length when compared to the control. Inoculation of A. chroococcum, P. putida, and LAP mix enhanced the seed germination rate of R. sativus, by 10, 5, and 30%, respectively, in comparison with the uninoculated seeds. The results demonstrated that the inoculation of seeds by select rhizobacterial strains showed remarkable enhancement to the radicle length of lettuce and radish seedlings.

• 한국자원식물학회지
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• 제11권3호
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• pp.245-251
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• 1998

Test plants with 10 days old primary leaves were indouclated by shaking infected seedlings with sporulating colonies over them in an inoculation room under the conditions of 20$\pm$1 $^{\circ}C$ with constant illumination of 2.500 lux and 100% realtive humidity. A seeding reaction of 4 days after inoculation appreared in the trisomic types as opposed to Tri-5B line had been symtoms of a fungus 3 days after inoculation. The infection types of 8 days after inoculation were recognized with higher susceptibility to each trisomics in A genomie than B-genome. Tri-2A line showed less condium and there appeared symptoms of a conditions of mottle and formed papilla, and haustorium was not formed. However, Tri-5B line had much condium one overall leaves and showed a symtom like necrosis compared with normal plant. Moreover, Tri-5B line showed high sensitivity and high germination number of condium. These results inferred that resistant gene located on 2A chromosome and susceptibility gene is located on the chromosome 5B.