• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1250-1258
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• 2009

Bacillus spp., as a type of plant growth-promoting rhizobacteria (PGPR), were studied with regards promoting plant growth and inducing plant systemic resistance. The results of greenhouse experiments with tobacco plants demonstrated that treatment with the Bacillus spp. significantly enhanced the plant height and fresh weight, while clearly lowering the disease severity rating of the tobacco mosaic virus (TMV) at 28 days post-inoculation (dpi). The TMV accumulation in the young non-inoculated leaves was remarkably lower for all the plants treated with the Bacillus spp. An RT-PCR analysis of the signaling regulatory genes Coil and NPR1, and defense genes PR-1a and PR-1b, in the tobacco treated with the Bacillus spp. revealed an association with enhancing the systemic resistance of tobacco to TMV. A further analysis of two expansin genes that regulate plant cell growth, NtEXP2 and NtEXP6, also verified a concomitant growth promotion in the roots and leaves of the tobacco responding to the Bacillus spp.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.309-309
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• 2017

The experiments were carried out in open experimental field of Field Crops Research Institute, Hai Duong, Vietnam in Winter Spring seasons 2015-2016 and 2016-2017 for finding high yielding of Korean chipping potato varieties which are adaptable to Vietnam condition. Six varieties of Korean potato (G1, G2, G4, G10, B1, B2) were experimented. The control variety (G6) was Atlantic which has long been a standard chip variety. The results showed that, for a hill, there was positive correlation between number of stems and number of tubers. The hill yield also showed highly relation to the plant height and number of tubers. Even though the growth and yield of potatoes grown in the season 2016-2017 were significant higher than these of potatoes grown in the season 2015-2016, their percentages of tubers infected by scab disease were much higher. This is probably because of irregular soil moisture content at the tuber forming duration. While G1, G6 and B1 are white flesh varieties, the remaining are yellow flesh varieties. There are two shapes types among experimented varieties: oblong (G1, G10, B1) and round shape (G2, G4, G6, B2). The total yields of varieties G1, G2, B1, B2 were higher than the total yield of the control variety from 16.5-49.4% in the season 2015-2016 and from 39.8-75.6% in the season 2016-2017.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.17-22
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• 2015

A total of CNU 28 hybrids were developed at the CNU Corn Breeding Lab. were evaluated to identify new cultivars in botanical characteristics, fresh yield per 10a and taste qualities. Most of these hybrids were stable in environmental stresses such as lodging, disease and insects. Stem height ranged from 115.0 to 239.3 cm, and ear height ranged from 30.7 to 107.0 cm. The ear height to stem height ratio was showed low than 50% of standard as a stable plant type to lodging. The range of ear length was 14.2 cm to 23.0 cm. Especially, CNU 13H-73 was very longest ear as a 23 cm. The fresh yield per 10a was high in purple of CNU13H-79 hybrid than control hybrid Miheuckchal, and CNU13H-73 in white hybrid was similar Yeonnong check hybrid. The 100-kernel weights in CNU13H-3 and CNU13H-9 hybrids were higher than that of the control hybrid. CNU13H-98 among hybrids had a 100-kernel weight of 20.32 g, which was heavier than that of the control hybrid Daehackchal Gold 1. The average pericarp thickness was $41.4{\mu}m$, CNU13H-46 among hybrids had a very thin pericarp as a $35.5{\mu}m$. The mean sugar content of the used hybrids was 14.95 brix%; CNU13H-73 and CNU13H-55 had higher than Mibak2 as a control hybrid.

• Research in Plant Disease
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• v.14 no.3
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• pp.223-225
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• 2008

This study was carried out to identify the Rice black-streaked dwarf virus that infected maize plants collected from Gochang-gun in Jeollabukdo in 2005. The genomic dsRNA from infected plants was extracted and the genome pattern was analyzed by polyacrylamide gel electrophoresis. Results of the electrophoresis revealed the already known to-segment genome and the difference of mobility was confirmed in isolates by collected areas. The RBSDV was identified from the result of RT-PCR using the template of extracted dsRNA and specific primer. The results of S10 cloned to pGEM-T vector and the conducted in sequence analysis consisted of 1,801nt and 559aa. This was of the same size as the RBSDV S10 identified in rice, and the change was confirmed in 18 base and displayed homology of 99%.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.591-599
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• 2020

Phytophthora root and stem rot reduce soybean yields worldwide. The use of R-gene type resistance is currently crucial for protecting soybean production. The present study aimed to identify the genomic location of a gene conferring resistance to Phytophthora sojae isolate 2457 in the recombinant inbred line population developed by a cross of Daepung × Daewon. Singlemarker analysis identified 20 single nucleotide polymorphisms associated with resistance to the P. sojae isolate 2457, which explained ~67% of phenotypic variance. Daewon contributed a resistance allele for the locus. This region is a well-known location for Rps1 and Rps7. The present study is the first, however, to identify an Rps gene locus from a major soybean variety cultivated in South Korea. Linkage analysis also identified a 573 kb region on chromosome 3 with high significance (logarithm of odds = 13.7). This genomic region was not further narrowed down due to lack of recombinants within the interval. Based on the latest soybean genome, ten leucine-rich repeat coding genes and four serine/ threonine protein kinase-coding genes are annotated in this region, which all are well-known types of genes for conferring disease resistance in crops. These genes would be candidates for molecular characterization of the resistance in further studies. The identified R-gene locus would be useful in developing P. sojae resistant varieties in the future. The results of the present study provide foundational knowledge for researchers who are interested in soybean-P. sojae interaction.

• Korean Journal of Veterinary Research
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• v.50 no.4
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• pp.323-326
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• 2010

Candidiasis is a mycosis caused by the mycelial yeast of the Candida genus which is opportunistic pathogen of humans, animals, and birds. Under some conditions such as prolonged antibiotic therapy, overcrowding, and immunosuppression, the opportunistic Candida can cause disease. Chicken candidiasis is sporadically occurred and characterized by unsatisfactory growth, listlessness, roughness of feathers, and death. A case of 23 weeks old layer with history of increased mortality and anemia was submitted to our Lab. At necropsy, the characteristic lesions were observed in the crop and proventriculus. The whitish pseudomembrane, that are peeled easily, was found in the crop. Proventriculus was swollen and the mucosa was covered with hemorrhagic exudate. The histological changes of the affected crop are epithelial hyperplasia, hydropic degeneration, and mycelia formation. Smears made from the necrotic mucosal surfaces of the crop revealed the presence of large number of yeast cells and mycelia. Pure cultures of yeast colonies were obtained from the potato dextrose agar. The yeast cells were identified as Candida albicans by gene sequencing. To our knowledge, this is the first report of candidiasis in chickens with anemia in Korea.

• Korean Journal of Medicinal Crop Science
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• v.23 no.6
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• pp.473-479
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• 2015

Background : To control ginseng gray mold, farmers have mainly used inorganic chemical based fungicides. The recent emergence of fungicide resistance has reduced the effectiveness of such control methods. Such pesticides also carry additional problems, such as diffuse pollution. Methods and Results : Six treatments of organic agricultural materials were tested for control of ginseng gray mold, CAPW (Chrysophanic acid + Phytoncide + Wood vinegar), EmEWV (Emodin + Ethanol + Wood vinegar), CEWV (Curcumin + Eugenol + Wood vinegar), Bacillus subtilis, soybean oil and sulfur. The control effect for gray mold by a single application of the agrochemical fungicide industrial Fenhexamid wettable powder (WP) was 84.4%. The control effect by CAPW, EmEWV and CEWV varied between 52.7 - 64.9%. The control effect by B. subtilis, soybean oil, and sulfur were 32.9 - 59.2%. Conclusions : In the field tests, CAPW showed the highest control effects when used before, and at first stage of disease incidence, against ginseng gray mold.

• The Plant Pathology Journal
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• v.29 no.4
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• pp.446-450
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• 2013

The ascomycete fungus Fusarium graminearum is a major causal agent for Fusarium head blight in cereals and produces mycotoxins such as trichothecenes and zearalenone. Isolation of the fungal strains from air or cereals can be hampered by various other airborne fungal pathogens and saprophytic fungi. In this study, we developed a selective medium specific to F. graminearum using toxoflavin produced by the bacterial pathogen Burkholderia glumae. F. graminearum was resistant to toxoflavin, while other fungi were sensitive to this toxin. Supplementing toxoflavin into medium enhanced the isolation of F. graminearum from rice grains by suppressing the growth of saprophytic fungal species. In addition, a medium with or without toxoflavin exposed to wheat fields for 1 h had 84% or 25%, respectively, of colonies identified as F. graminearum. This selection medium provides an efficient tool for isolating F. graminearum, and can be adopted by research groups working on genetics and disease forecasting.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.08a
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• pp.100-113
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• 2005

Leaf color and plant vigor are key indicators of crop health. These visual plant attributes are frequently used by greenhouse managers, producers, and consultants to make water, nutrient, and disease management decisions. Remote sensing techniques can quickly quantify soil and plant attributes, but it requires humans to translate such data into meaningful information. Over time, scientists have used reflectance data from individual wavebands to develop a series of indices that attempt to quantify things like soil organic matter content, leaf chlorophyll concentration, leaf area index, vegetative cover, amount of living biomass, and grain yield. The recent introduction of active sensors that function independent of natural light has greatly expanded the capabilities of scientists and managers to obtain useful information. Characteristics and limitations of active sensors need to be understood to optimize their use for making improved management decisions. Pot experiments involving sand culture were conducted in 2003 and 2004 in a green house to evaluate corn and red pepper biomass. The rNDVI, gNDVI and aNDVI by ground-based remote sensors were used for evaluation of corn and red pepper biomass. The result obtained from the case study was shown that ground remote sensing as a non-destructive real-time assessment of plant nitrogen status was thought to be a useful tool for in season crop nitrogen management providing both spatial and temporal information.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.57-63
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• 2001

Barley Yellow Dwarf Virus (BYDV) has been a major disease causing a severe loss of yield in winter cereals worldwide. It has been recently reported that BYDV occurs frequently in wheat field and also causes serious yield reduction in Korea. This study was performed to investigate the regional distributions of BYDV strains in Korea and to identify the resistant cultivars or lines of wheat to the predominant BYDV strains, providing basic information for the breeding of BYDV-resistant wheat varieties. Using RT-PCR and EcoRI digestion methods, the regional distribution of BYDV strains in Korea from 1999 to 2000 showed that PAV strain was mainly detected about 65% (Vic-PAV 52.6% ; CN-PAV 47.4%) and MAV strain about 3%. Using ELISA test for the examination of BYDV resistance with 17 cultivars and 4 lines among Korean wheat, three cultivars, Gurumil, Topdongmil, and Olgurumil, were susceptible to BYDV and the others were resistant. In plant growth and yield component responses to BYDV infection, Gurumil showed significant difference between the uninfected and the infected, suggesting the most susceptible to BYDV among Korean wheat, but Eun-pamil and Seohae118 did no difference, an indication that they have the highest resistance.