• Mycobiology
• /
• v.35 no.4
• /
• pp.235-237
• /
• 2007

Leaf blight and bulb rot symptoms were observed on narcissus plants grown in Yongin, Cheongwon and Namhae areas in Korea during disease survey from 1999 to 2002. A total of 15 isolates of Botrytis sp. were obtained from the infected plant parts of narcissus. All the isolates were identified as Botrytis narcissicola based on their morphological and cultural characteristics. Three isolates of B. narcissicola were tested for their pathogenicity to leaves and bulbs of narcissus by artificial inoculation. All the isolates induced leaf blight and bulb rot symptoms on the plants of narcissus by artificial inoculation. The symptoms induced by artificial inoculation were similar to those observed in the fields. This is the first report of narcissus smoulder caused by B. narcissicola in Korea.

• Mycobiology
• /
• v.35 no.4
• /
• pp.238-240
• /
• 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.

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

• Journal of Forest and Environmental Science
• /
• v.29 no.2
• /
• pp.173-180
• /
• 2013

Berries of Korean mistletoe (Viscum album var. coloratum [Kom.] Ohwi) contained one seed, which have, in general, one or two embryos but very rarely three embryos. Mucilaginous substances in berries may help them adhere to the branches of host trees. It was observed that seeds need more than one and half years to develop into normal and healthy seedlings from the time of inoculation. Many factors such as adhesion of berry, thickness of host branch, orientation of haustorial root, etc. influenced the successful development of mistletoe plants. Through the application of six-year observation results on the germination of seeds and growth of seedlings, about 80% of germination rate for mistletoe seeds and 61% of survival ratio for germinated seeds, which is more than 23 times higher in natural conditions, were obtained after inoculation of seeds on the one-year-old branches of Malus pumila var. dulcissima and Quercus mongolica trees. The technological aspects of the success can be applied to other host plants and provide a critical clue to an artificial propagation system, for this medicinally valuable genus. This is the first successful report on artificial inoculation and plant development of Korean mistletoe.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.69.2-70
• /
• 2003

For the selection and breeding of chestnut varieties resistant to the chestnut blight fungus Cryphonectria parasitica, disease resistance and susceptibility of 28 varieties widely planted and growing in Korea were evaluated by artificial inoculation of a pathogenic fungus. For this experiment, a typical virulent strain (KCPC-19) was selected. Artificial inoculation was conducted into all varieties by using two different materials and methods, i.e., bark and wood tissue sections in the laboratory and living trees in the field. In the bark and wood tissue section method, the size of necrotic area and canker development on chestnut varieties were examined and compared 4 days after inoculation. There were wide variations of chestnut varieties in disease resistance and susceptibility against chestnut blight fungus, but 3 varieties, Daebo！, Ishizuchi, and Sandae, were shown to be relatively resistant to the disease with the necrotic area of 0.95-1.03 cm2, while Arima was the most susceptible with the size of 2.0 cm2. In the living tree inoculation examined 5 weeks after inoculation, 3 varieties, Daebo, Ishizuchi, and Riheiguri, showed the higher resistance, but Tono 2 did the highest susceptibility among tested varieties.

• The Plant Pathology Journal
• /
• v.19 no.5
• /
• pp.257-259
• /
• 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.

• The Plant Pathology Journal
• /
• v.19 no.5
• /
• pp.231-234
• /
• 2003

Brown rot symptoms severely occurred on fruits of apricot and mume grown in Changnyeong, Suwon and Yeongi in Korea during a disease survey in June 2002. A total of 32 isolates of Phomopsis sp. was obtained from the fruit rot symptoms. All isolates were identified as Phomopsis vexans based on their morphological and cultural characteristics. Four isolates of the fungus were tested for pathogenicity to fruits of apricot and mume by artificial inoculation. All isolates induced brown rot symptoms on the fruits of apricot and mume by wound inoculation. Unwounded inoculation also induced symptoms on mume fruits but not on apricot fruits. The symptoms on the fruits induced by artificial inoculation were similar to those observed in the orchard. The pathogenicity tests revealed that mume was more susceptible to the pathogen than apricot. This is the first report of brown rot of apricot and mume caused by P. vexans.

• The Korean Journal of Mycology
• /
• v.27 no.6 s.93
• /
• pp.378-382
• /
• 1999

This study was carried out to improve an artificial culture techniques and antioxidative activity of the crude extract isolated from sclerotia of Poria cocos(Fr.) Wolf. In the test of different spawns and inoculation method, the sclerotia formation, number of sclerotia and production yield were excellent in the both sides inoculation method of log spawn, whereas the both side inoculation method of sawdust spawn was poor in sclerotia formation and yield. The optimal spawn and inoculation method for the quality and productivity of P. cocos was in the order of log spawn (both sides inoculation > log spawn(cutting section inoculation) > sclerotia (both sides inoculation) > sawdust spawn (both sides inoculation). The physiological activity substance, crude extract content of P. cocos NIAST 13007 was about 83%. As the concentration of crude extracts increased, the relative viscosity tended to be increased. However, as the concentration of sodium chloride increased, the relative viscosity did not affected. In antioxidative activities, electron donating ability (EDA) of P. cocos was about 10% of butylated hydroxytoluene (BHT). Thiobarbituric acid (TBA) value was similar to that of the vitamin C, however the peroxide value (POV) was lower than those of BHT and vitamin C.

• Korean Journal of Plant Resources
• /
• v.11
• /
• pp.126-128
• /
• 1998

• 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.