• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.456-462
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• 2009

Bacterial pustule (BP), caused by Xanthomonas axonopodis pv. glycines, is prevalent disease in major soybean production areas. BP can reduce seed yield as well as seed quality. To identify the genomic region associated with the resistance to BP, QTL analysis was conducted using $F_{10}$ RIL (recombinant inbred lines) population, Keunolkong${\times}$Shinpaldalkong. Four QTLs for BP disease were identified on the linkage group B2, D2, I and K in field accounts for 36.4% of the phenotypic variation. Especially, QTL at near of Satt135 on LG D2 was identified in green house experiment explaining 20.9% of the phenotypic variation was found to be a major QTL conferring BP. One of these QTLs, Satt135 on the LG D2, was also identified in green house experiment. In both field and green house condition, the position of major QTL for BP was detected between Satt135 and Satt397 on the LG D2. The major QTL for BP may be used for minimizing soybean BP through effective marker-assisted selection (MAS).

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.707-710
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• 2010

A new perilla cultivar, 'Bomnaeyeop 1 ho' was developed by, Kangwon National University in 2008. Its characteristics were investigated three times from 2006 to 2008 under optimal condition of cultivation. 'Bomnaeyeop 1 ho' can be characterized by dark green leaf color and tall plant height. This cultivar has more number of flower cluster and ear per cluster compare to 'Saeyeupsil' control. From result of GC/MS analysis, main compounds consist of perilla ketone, beta-caryophyllene and myristicin in 'Bomnaeyeop 1 ho' cultivar.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.56-60
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• 2010

This study was carried out to develop of macro-protocol and the biosafety guide Golden Rice, modified vitamin A at large scale GMO field. Commercialization of genetically modified (GM) plants will be required the assessment of risks associated with the release of GM plants that should include a detailed risk assessment of their impacts in the environment and human health. Prior to GM plant release, applicants should provide the information on GM crops for approval. A total of $4,700m^2$ GM field, each of Golden Rice and 'Nakdong' were used for further analysis on agronomic traits and pathogenesis. Generally plant growth and panicle number in the transgenic lines were lower than in the wild type under field condition. The major agronomic traits such as plant growth, grain quality in Golden Rice were similar than in 'Nakdong'. The yield difference was due to reduced ripened rate and the 1,000 grain weight. The grain shape was similar donor plant, however, color of brown rice was different from segregation. Also the difference of pathogenesis reaction was not significant in the leaf blast and sheath blight between Golden Rice and 'Nakdong'. These results provided the agronomic data and pathogenesis for risk assessment analysis of Golden Rice and suggested that the macro-protocol could be useful to detect GM plants.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.136-142
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• 2008

We conducted this study to compare physiological response according to growing conditions between superior and inferior family of Pinus densiflora. In 1981, open-pollinated (OP) progenies of P. densiflora were planted in Chuncheon (CC) and Naju (NJ). We selected KW2 as a superior family and KW23 as a inferior family based on volume index among 30 OP progenies. We calculated general combining ability of each 30 OP progenies in each sites, and compared family growth rank. We collected needles of selected families in CC and NJ, and analyzed chlorophyll content, nitrated reductase (NR) activity, nitrogen content, and superoxide dismutase (SOD) acitivity. In CC, chlorophyll content and nitrogen content were more in needles of KW2 than those of KW23. In NJ, KW2 showed higher NR activity than KW23, and according to site, families in CC showed higher NR activity than those in NJ. SOD activities of both families were higher in NJ, and KW23 showed higher activity than KW2 in both sites. Consequently, inconsistency of the growth performance of two families was caused by different genetic and physiological responses.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.50-55
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• 2010

The R-r:standard (R-r:std) allele of maize R gene complex consists of S subcomplex and P component; the S subcomplex regulates anthocyanin pigmentation of seed aleurone layer, and the P component confers pigmentation of the other plant parts. The S subcomplex contains two functional genes, S1 and S2 components. In the presence of Pl gene some alleles of R gene induce anthocyanin pigmentation of pericarp. In the present study, the effects of different R alleles on the anthocyanin pigmentation of pericarp in the presence of Pl gene were analyzed in order to identify the R gene component responsible for pericarp pigmentation. The results show that R-ch and r-ch alleles condition similar degrees of pericarp pigmentation, and that R-r:Ecuador (R-r:Ec) conditions stronger pigmentation. The r-ch allele, which is inferred that its S subcomplex has lost function but the P component is normal, induces pericarp pigmentation in the presence of Pl gene. On the contrary, the R-g:g1111 allele, derived from R-r:Ec and inferred that its S subcomplex functions normal but the P component has lost its function, did not induce pericarp pigmentation in the presence of Pl gene. Moreover, PCR analysis of genomic DNA's of R-ch and r-ch indicate that R-ch maintains both P and S1 components, whereas r-ch lacks for the S1 component. Taken together, The results suggest that the P components of R alleles inducing pericarp pigmentation in the presence of Pl gene are responsible for pericarp pigmentation.

• Journal of Animal Science and Technology
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• v.64 no.1
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• pp.1-9
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• 2022

Equilume light masks had no impact on hastening the resumption of estrous cyclicity in mares maintained in outdoor pastures on the mainland of Korea due to the cold weather conditions. Jeju Island is a major horse-breeding site in Korea and is warmer than the mainland during the winter season. Therefore, the primary objective of this study was to explore the efficiency of the Equilume light mask on the resumption of seasonal estrous cycles in Thoroughbred mares on Jeju Island. A total of 20 nonpregnant mares were randomly divided into the Equilume light mask (n = 9) and stable lighting (n =11) groups. The experiment was performed at seven different horse-breeding farms located on Jeju Island from November 15, 2020, to February 15, 2021. The mares were exposed to the respective lights from 16:00 to 23:00. Follicle size and uterine edema were measured by ultrasound scanning. Body condition scores (BCS) were also monitored during the experiment. Statistical analysis was conducted using the SAS and SPSS software, and p-values of < 0.05 were considered statistically significant. Two of the nine (22.2%) mares in the Equilume light mask group and three of the 11 (27.28%) mares in the stable lighting group were still cycling in December and January, which were considered as all-year-round cycling mares. On February 15, there was no difference between groups in the resumption of early seasonal estrus cycle, which was determined by follicles > 25 mm in addition to uterine edema. All mares in the Equilume light mask group and five of the eight mares (62.5%) in the stable lighting group had resumed cycling. Interestingly, six of the seven mares (87.5%) in the Equilume light mask and four of eight mares (50%) in the stable lighting group had already ovulated on February 15 (p > 0.05), as determined by the presence of a recent corpus luteum. No difference was observed in BCS and uterine edema between groups (p > 0.05). In conclusion, the Equilume light mask can be an effective approach to induce early seasonal estrus cycles of mares in Jeju Island, and it also enhances the efficiency of farm management by reducing labor.

• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.431-438
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• 2024

Hops enhance beer flavor and bitterness, acting as a preservative. In recent years, the booming trend of craft beer has prompted the introduction of foreign hop varieties for cultivation and production in South Korea. This study focuses on developing efficient in vitro culture condition of the hop (Humulus lupulus L.) variety 'Cascade' for treatments of plant growth regulators, i.e. IAA and Cytokinin. Using Auxin IAA and Cytokinin 2iP, Zeatin, BAP, and TDZ on MS medium as plant growth regulators, the experiment involved removing three nodes from the shoot apex. In vitro hop culture showed the highest shoot proliferation rate when only IAA was added, with approximately 21% higher compared to the combination with Cytokinin. Notably, IAA 0.1 mg/L + BAP 1 mg/L resulted in a superior shoot proliferation rate of around 91%. IAA 0.1 mg/L + BAP 1 mg/L was advantageous for shoot elongation. Callus induction occurred with TDZ, while control or IAA-only conditions exhibited shoot and root growth. Cytokinin addition led to callus formation and increased weight. Assessing survival and soil adaptation during in vitro hop seedling acclimatization involved maintaining near 100% humidity initially, gradually reducing it over three weeks. When transferred outdoors, 9 out of 10 seedlings acclimated successfully, confirming a 90% acclimatization rate.

• Korean Journal of Breeding Science
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• v.40 no.1
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• pp.31-38
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• 2008

This experiment was carried out to improve the anther culture efficiency of barley (Hordeum vulgare L.). Callus induction rates from anther cultures of the five domestic naked barley and four unhulled varieties ranged from 0 to 5.6%, and plant regeneration rate to callus was 30.4% in the donor plants grown in a greenhouse during winter, among which the green plant regeneration rates ranged from 0 to 4.4%. Plant regeneration rate was 30.4% in the donor plants grown in a greenhouse during winter, whereas 21.3% in the normal field condition in spring. In addition, callus induction rates were 19.2% in plants grown in a normal field and 7.2% in drought-stressed condition, respectively. Being Considered the anther culture efficiency affected by the sampling time, the optimum sampling stage of anthers was 3~4 days before heading when the length between the 1st and 2nd auricles reaches 5 to 10 cm and at the uninucleate of pollen which the tip of the 2nd auricle aligns with the middle of panicle in the leaf sheath. Best callus induction rates came from the anthers stored at $4^{\circ}C$ for 3 weeks in a 10 to 15 cm diameter polyethylene bag with 5 to 10 panicles and Duwonchapssalbori and Saessalbori showed the higher induction rate of 4.8% and 1.7%, respectively.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.13 no.2
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• pp.67-73
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• 2007

A respiration rate analysed by enzyme kinetics-based respiration model and gas permeability data of LDPE film were applied to design the optical modified atmosphere (MA) packaging condition of persimmon (Diospyros kaki cv. Fuyu) fruits. The fruit quality rapidly decreases due to physiology disorder such as softening and peel blackening. $O_2$ permeance ($Q_{O2}$ in $ml{\cdot}hr^{-1}{\cdot}atm^{-1}{\cdot}m^{-2}$) and $CO_2$ performance ($Q_{CO2}$ in $ml{\cdot}hr^{-1}{\cdot}atm^{-1}{\cdot}m^{-2}$) of low density polyethylene (LDPE) film samples were measured at $0^{\circ}C$ and described as function of thickness (L in ${\mu}m$) as $Q_{O2}=(2540{\times}1/L)-16$, and $Q_{CO2}=(13742{\times}1/L)-70$, respectively. MA package containing single persimmon fruit of 225g was designed and tested experimentally at $0^{\circ}C$ by using LDPE films. Package atmospheres predicted from the relationship of $O_2$, $CO_2$ and $N_2$ balances on the packages was in good agreement with those obtained experimentally. Physiology disorder occurrence was the lowest at 52 ${\mu}m$ package that attained optimum gas condition ($O_2$ 2.8% and $CO_2$ 5.4%). The computer simulation was found to be effective to help to design the optimum MA packaging condition of individual persimmon fruit.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.302-309
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• 1987

One hundred rice varieties were tested for their level of resistance to sheath blight disease at adult plant stage in field condition through 1984 to 1986. Rice plants were grown under ordinary seasonal culture and inoculated by k-2 fungus isolate during three years. k -1 isolate was also inoculated separately in 1984 and test under late seasonal culture was conducted in separate field in 1985. Degree of damage by the disease observed at 25 days after heading was used to identify the level of resistance of the rice varieties tested. Varietal differences of degree of damage were significant in five tests during three years, and the genotypic variance of degree of damage was always higher than environmental variance among varieties tested. Positive correlations between testing years, between cultural seasons, and between isolates inoculated were found in degree of damage of varieties tested for two or three years continuously. Degree of damage by the disease was correlated negatively with heading date of rice varieties except 1984 tests. Thus, the level of resistance should be compared among the variety group having almost same heading date in field condition, and late and extremely late variety groups should be tested for their level of resistance under appropriate environmental condition. Gayabyo, an early heading variety, and SR9713-54-3, a medium heading breeding line, showed consistent lower value of degree of damage during two or three years. These two varieties were selected as moderate resistant germplasm.