• The Korean Journal of Ecology
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• v.2 no.1
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• pp.15-20
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• 1978

Pathological and anatomical studies on the cause of the crown gall like symptoms associated with the chestnut nurse grafts were undertaken. The crown gall bacterium, Agrobacterium tumefaciens, was isolated from the gall tissues of chestnut nurese grafts by using selective media developed by S초개소 et al. and kado and Heskett. Typical crown gall symptoms appeared on tomato, castor bean and geranium plants 10~21 days following inoculation with the bacterium isolated from the gall tissues of chestnut nurse grafts. Agrobacterium tumefaciens was reisolated from crown gall tissues of tomato, castor bean and geranium. Anatomical studies on the origin, growth and differentiation of the gall tissues of the chestnut nurse grafts confirmed that the gall tissues are of crown gall origin. Masses of Agrobacterium tumefaciens were observed from gall tissues of chestnut nurse grafts, so it could be confirmed that the crown gall symptoms prevalent on chestnut nurse grafts are caused by the crown gall bacterium, Agrobacterium tumefaciens.

• Research in Plant Disease
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• v.10 no.4
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• pp.227-230
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• 2004

Occurrence and epidemiology of crown gall caused by A. tumefaciens in persimmon tree was investigated. Persimmon tree was more sensitive to crown gall disease than peach and jujube tree. Over 80% persimmon trees were infected to crown gall in all investigated region with no relation to planted years. Yield of infected tree was severely decreased to 54%. Incidence of crown gall in nursery field of persimmon tree was also severe and the infection rate of persimmon seedlings collected from market was 34%. It was guessed that the primary inoculum of crown gall caused by A. tumefaciens is infected persimmon seedlings.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.1
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• pp.36-42
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• 1991

The present study was conducted to obtain some basic information on the shoot formation from crown gall callus and the characteristics of teratoma shoot derived from crown gall induced by inoculation of Agrobacterium tumefaciens C58. Crown gall callus could be continuously cultured on the phyohormone free basic medium. The growth of crown gall callus was inhibited when BA were added to the cultural media. Shoot formation from crown gall callus fail to be initiated except teratoma shoot which induced on the phytohormone free medium after several subculture on rare occasions. Teratoma shoot could not form root and grow as normal shoot. Addition of BA to cultural media was not effective for shoot elongation, reduction in multiple shoot formation, but IBA was somewhat effective for shoot elongation of teratoma shoot, never for root formation.

• The Plant Pathology Journal
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• v.39 no.2
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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.

• Journal of Ginseng Research
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• v.10 no.1
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• pp.45-54
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• 1986

These studies were carried out to obtain the basic information about transformation of ginseng plant by potential vector system, utilization of opine compound by Agrobacterium sap. , and initiation of crown gall tumor callus. Crown gall tumors were induced from stem of Panax ginseng C.A. Meyer by infection of Agrobacterium tumefaciens. Therefore, it was clarified that transformation of ginseng by Ti plasmid was possible. The crown gall tumors induced by Agrobacterium tumefaciens isolated. from the soil were different in a shape, size, and growth rate. Especially, infection of ginseng by Agrobacterium tumefaciens Y104 led to the amorphic tumor, Tumor tissue derived from stem crown gall could not be continuously cultured on the medium which did not contain phytohormone, and did not form the callus even on the medium supplemented with 2,4-D. On the other hand, the root crown gall tumors formed the calli but the formation rate of callus was quite low. As for the utilization of octopine and nopaline, it was found that 3 strains of Agrobacterium app., Y104, Y110 and C58, utilized nopaline only, Y109 utilized octopine, and Y101 failed to utilize either compound.

• Journal of Forest and Environmental Science
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• v.36 no.4
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• pp.290-297
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• 2020

This study analyzed and compared the damage rate, natural parasitic rate, and the morphological characteristics of Thecodiplosis japonensis larvae, which inhabit forest areas as control areas to large urban areas in 2018 and 2019. This research was conducted to provide basic data for the management of Thecodiplosis japonensis, which harm pine needles, and the results were as follows. First, the gall formation rate of Thecodiplosis japonensis collected from urban areas was upper-crown 35.59% and 34.25%, mid-crown 25.57% and 27.95%, and lower-crown 25.34% and 26.61%; the gall formation rate of Thecodiplosis japonensis was in the order of upper-crown>mid-crown>lower-crown in 2018 and 2019, respectively. In the control areas, the gall formation rates of Thecodiplosis japonensis in mountain villages in 2018 and 2019 were upper-crown 17.72% and 21.78%, mid-crown 13.85% and 16.97%, and lower-crown 15.12% and 15.79%; thus, in the order of upper-crown>lower-crown>mid-crown. The number of larvae in the galls of needles damaged by Thecodiplosis japonensis was as follows: the average number of larvae in the pine trees of urban areas was 9 and 8 in the upper-crown, 7 and 8 in the mid-crown, and 6 and 7 in the lower-crown respectively. This shows that the number of larvae was fewer in the lower-crown than the upper-crown, and that the number of larvae was higher in 2018 than in 2019. For natural parasitic rate of Thecodiplosis japonensis, the gall formation rate and natural parasitic rate of Thecodiplosis japonensis were surveyed; the natural parasitic rate was 12.5% and 11.8% in urban areas while the rate was 21.7% and 20.9% in mountain villages in respectively in 2018 and 2019.

• The Plant Pathology Journal
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• v.16 no.5
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• pp.290-293
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• 2000

The main grape producing regions in Korea were surveyed for the occurrence and relative incidence of crown gall disease on grapevine. The results of the survey showed that the disease tended to affect tetraploid cultivars, which produce a large and sweet fruit but are very weak to cold weather. Incidence of crown gall disease was high on the tetraploid cultivars, Kyoho (Gerbong), Daebong, and Black Olympia while it was low on the diploid cultivars, Cambell Early and Sheridan. The disease incidence was very high on Anseong, Cheonan, and Chincheon, where the major growing areas of tetraploid cultivars and grapevines were burried in the winter to protect from freeze injury, whereas it was low in Yungdong, Kimcheon, and Nonsan. Crown gall disease did not increased with grapevine age on both Cambell Early and Kyoho. It remained low in Cambell Early, but high for all ages on Kyoho, Galls were found on the crown region and mid part of the trunk, but more galls were on small branches and canes on Kyoho grapevines. More than one third of ZKyoho grapevines inspected had galls on multiple locations on grapevines. On Kyoho, 56.3% of the galls covered more than 50% of the crown gall disease affects severely on the cultivar.

• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.31-35
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• 1999

Morphological characteristic during formation of tobacco crown gall tumor and genetic tumor, and their differential response to growth regulator were investigated in in vitro culture. Crown gall tumor was induced from tumor tissue transformed by infecting Agrobacterium tumefaciens C58. Genetic tumor was induced from tumor tissue which was induced spontaneously from reciprocal interspecific hybrids between Nicotiana glauca (2n=24) and Nicotiana langsdorffii (2n=18). Morphological characteristic of crown gall tumor, genetic tumor, and teratoma shoot was very similar, and they were actively proliferated on hormone-free medium. Typical tumor callus and teratoma shoot formed from crown gall tumor on the hormone-free medium. On the contrary, tumor callus derived from genetic tumor formed as a crown gall tumor callus on the medium supplemented with 0.5 mg/L of 2,4-D, and lots of teratoma shoots without any root formed on the hormone-free medium. Root development from the teratoma shoots was hardly obtained on the medium with IAA, GA and active carbon. However, teratoma shoots with roots, as normal shoots, were initiated occasionally on the hormone-free medium. These shoots also formed new genetic tumor on the stem, which leaves formed lots of teratoma shoot on the hormone-free medium in in vitro culture.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.70.2-70
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• 2003

To evaluate the resistance to crown gall in grape rootstocks, cuttings from twenty seven grape rootstocks were inoculated with Agrobacterium vitis Cheonan 493 and size of galls from grapevines was measured in a greenhouse. Tumors were formed in all varieties of grape rootstocks tested in this study and no grape rootstock variety was immune to crown gall. Tumors were found on the stems of all plants tested in '196-17'and '41B' Based on measuring size and weight of galls formedon the stem of grape rootstocks, '779P' was extremely susceptible to crown gall. Some varieties such as 'Gloire', '140R', '101-l4M', '3309C', and '333EM' found to be resistant, while '99R', '1447P', 'Rupestris du lot', '110R', 'Freedom', and '41B'were susceptible and '1103P', '5C', '420A', 'Golia', and '5BB' were moderately susceptible to crown gall.

• Korean Journal of Plant Resources
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• v.11 no.2
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• pp.176-176
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• 1998

This study was carried out to obtain the information for growth characteristics of crown gall tumor and hairy root transformed by Agrobacterium spp,. on the media with phytohormones, casein hydrolysate and activated charoal. Crown gall tumors and hairly roots were formed respectively on potato tuber discs infected by tumerfaciens A ch 5 and A.rhizogenes ATCC15834. These tumors and roots could be grown on the phytohormone free media. PCR analysis of Rol C and Vir C gene fragments confirmed that crown gall root was prompted on the medium containing 2,4-D 2mg/l with casein hydrolysate lg/l. The survival ration of crown gall tumor callus derived from potato increased on medium containing the activated charcoal 0.5∼0.2mg/l because of the prevention, on the other hand, hairly roots were necrosis on the same medium. Callus derived from hairly root were excellently grown for a short time by suspension culture on liquid medium containing 2.4-d 2mg/L and casein hydrolysate lg/l.