• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.2
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• pp.98-105
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• 2018

The sale of brown rice batches composed of rice produced in different years is prohibited in Korea. Thus, new methods for the identification of the year of production are critical for maintaining the distribution of high quality brown rice. Here, we describe the exploitation of an enzyme that can be used to discriminate between freshly harvested and one-year-old brown rice. The degree of enzyme activity was visualized through freshness test with Guaiacol, Oxydol, and p-phenylenediamine reagents. With electronic eye equipment, we selected 29 color codes for identifying new brown rice and old brown rice. The discrimination power of selected color codes showed a minimum of 0.263 to a maximum of 0.922 and an average value of 0.62. The accuracy with which new brown rice and old brown rice could be identified was 100% in principal component analysis (PCA) and discriminant function analysis (DFA). The DFA analysis had greater discriminatory power than did the PCA analysis. A verification test using new brown rice, old brown rice, or a mixture of the two was then performed to validate our method. The accuracy of identification of new and old brown rice was 100% in both cases, whereas mixed brown rice samples were correctly classified at a rate of 96.9%. Additionally, in order to test whether the discriminant constructed in winter can be applied to samples collected in summer, new and old brown rice stored for 8 months were collected and tested. Both new and old brown rice collected in summer were classified as old brown rice and showed 50% identification accuracy. We were able to attribute these observations to changes in enzyme content over time, and therefore we conclude, it will be necessary to develop discriminants that are specific to distinct storage periods in the near future.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.193-200
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• 2017

BACKGROUND: Plant growth under smart greenhouse (that is plant factory system) conditions of an artificial light type is significantly depending on the artificial light sources such as a fluorescent lamps or Light-Emitting Diodes (LEDs) with specific spectral wavelengths regardless of the outside environmental changes. In this experiment, characteristics on the growth and compound synthesis of kale seedlings affected by light qualities and intensities provided by LEDs were mentioned. METHODS AND RESULTS: The kale seedlings which developed 3~4 true leaves were exposed by fluorescent lamps or LEDs lights of red (R), blue+white (BW), blue+red (BR) with 50 (L) or $100(H){\mu}mol/m^2/s^1$ photosynthetic photon flux (PPF) under hydroponic culture system of deep flow technique for 50 days. Shoot fresh weight increased under the RH, BWH, and BRH treatments with higher PPF. Shoot elongation of the seedlings decreased, and polyphenol synthesis promoted by the higher light intensity conditions. Sugar synthesis in the leaves was above 2 times greater under the RH treatment of monochromic red light quality with $100{\mu}mol/m^2/s^1\;PPF$ than $50{\mu}mol/m^2/s^1\;PPF$. CONCLUSION: The results show that the control of light quality and intensity in the smart greenhouse conditions with artificial lights significantly affects the growth and compound synthesis in the fresh kale leaves with higher culture efficiency compared to the conventional soil culture under greenhouse or field conditions. Researches on the optimum light intensities of the LEDs with special spectral wavelengths are necessary for maximum growth and metabolism in the seedlings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.185-192
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• 2006

This experiment was conducted to assess genetic diversity of waxy corn inbred lines and to identify SSR markers related to major characteristics affected kernel quality for improving waxy corn $F_1$ hybrid with good quality. Diversity of 64 waxy com inbred lines was evaluated using 30 microsatellite markers. The 30 microsatellite markers representing 30 loci in the maize genome detected polymorphisms among the 64 inbred lines and revealed 225 alleles with a mean of 7.5 alleles per primer. The polymorphism Information content (PIC) value ranged from 0.14 to 0.87, with an average of 0.69. Based on Nei's genetic distances, the 64 inbred lines were classified into 9 groups by the cluster analysis. The group I included 26 inbred lines (41%), other groups included 3 to 9 inbred lines. One-way analysis of variance was conducted to identify significant relationship between individual markers and major characteristics that affect kernel quality. The analysis showed that umc1019 was related to amylopectin and crude protein content, me 1020 to amylopectin content and peak viscosity, and bnlg1537 to 100-kernel weight, kernel length, and kernel width.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.673-683
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• 2014

This study was conducted to establish an efficient screening method to identify cucurbits resistant to powdery mildew. Powdery mildew fungus was obtained from a single lesion of infected cucumber leaf in 2010 at Daejeon. The fungus was identified as Podosphaera xanthii race 1 based on morphological characteristics and resistance responses of four melon differentials. Development of powdery mildew caused by the fungal isolate on 34 commercial cultivars of cucumber was investigated at three plant growth stages in a greenhouse. The degree of resistance of cotyledons of each cultivar to the fungus was not correlated with that of whole plant, but powdery mildew occurrence in the first true leaf was highly correlated with resistance at the level of the whole plant. Based on these results, the first true leaf of cucurbit cultivars can be used for screening of resistance to powdery mildew. In addition, variation of resistance of commercial 12 cucumber and 26 melon cultivars to the powdery mildew fungus due to different growing seasons was tested. In the case of cucumber, the resistance response in some cultivars was influenced by growing season. The resistant cultivars showed higher resistance in the warm season than in the cool season. By contrast, the resistant melon cultivars demonstrated strong resistance in all the tested growing seasons. Interestingly, the tested powdery mildew pathogen, a member of P. xanthii race 1, was not pathogenic on seven cultivars of watermelon (Citrullus lanatus). To follow up on this, diverse race 1 isolates of P. xanthii should be collected and tested.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.290-297
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• 2015

Based on the place of its origin, pear tree (Pyrus spp.) is largely divided into European pears (P. communis, cultivated mainly in Europe and the U.S.) and Asian pears (P. pyrifolia, P. bretschneideri, and P. ussuriensis, distributed and grown in East Asian countries including China, Japan, and Korea). Most pear trees have 17 chromosomes (diploidy, 2n=2x=34). Their genetic studies and precise cultivar breeding are highly restricted by conditions such as self-incompatibility controlled by S-locus and juvenility as one major character of fruit crops. Genetic studies on Pyrus have been promoted by the development of various molecular markers. These markers are being utilized actively in various genetic studies, including genetic relationship analysis, genetic mapping, and QTL analysis. In addition, research on pear genetic linkage maps has been extended to studies for the identification of QTL for target traits such as disease resistance and genetic loci of useful traits. NGS technology has radically reduced sequencing expenses based on massive parallel reactions to enable high-capacity and high-efficiency. NGS based genome analyses have been completed for Chinese pear 'Danshansuli' and European pear 'Bartlett'. In Korea, GWAS for agricultural valuable traits such as floral structure, ripening, and total soluble contents have been conducted through resequencing. GBS has been performed for 'Whangkeumbae', 'Cheongsilri', and 'Minibae'.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.196-203
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• 2015

AbstractLiving modified organisms (LMO) are one of the most widespread products of modern biotechnology after DNA discovery. Due to the decline of grain self-sufficiency rate and the increase of reliance on LMO imports in Korea, a series of concerns with regard to safety of living modified(LM) crops has been raised. The aim of this study is to establish the detection methods for unintentional release or growing of LMO plants in environmental conditions. To detect LM crop events, general concepts of specific primer design and PCR conditions were provided by the Joint Research Centre (JRC). The certified reference materials of seven LM events (4 soybean, 2 cotton and 1 corn) were obtained from the Institute for Reference Materials and Measurements (IRMM) and the American Oil Chemists' Society (AOCS). Genomic DNA from seven LM events were purified and PCR amplifications were carried out by using individual event-specific primer sets. LM-specific PCR products of all seven events were efficiently amplified by our methods. The results indicate that the established detection method for LMOs is suitable as a scientific tool to monitor whether the crops found in natural environments are LMOs.

• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.433-440
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• 2005

Four varieties of perilla(Perilla ocimoids L.) were tested to investigate the ecological adaptation of the crop to variations in sowing time extending from April 25 to July 25 with an interval of 30 days between each of the four sowing. As sowing time was delayed, the plant height, the number of first branches and cluster, the weight of fresh and dried stems, the day to germination and flowering decreased, showing a highly negative correlation between the showing dates and these characteristics, but a highly positive correlation between days to flowering and the required accumulated temperature. With early sowing under low temperature and long day conditions, it took about 132 days from sowing to flowering due to the long period of vegetative growth, but as sowing was delayed, the days to flowering decreased with a minimum period of 57 days. The yield of seeds in each case varied with each variety. Type A(Nonsan var.) and type B(Jinchon var.) had higher yields when sowed earlier. But type C(Namyang var. and Wooljin var.) had its highest yield in the plot sowed on May 25 and the 1000 grain weight showed a tendency to increase as sowing was delayed. In conclusion, the perilla was preyed to be a short-day plant that flowers from the begining to the middle of Sep. regardless of sowing time, so that the sowing time should be decided after due consideration of the length of the vegetative growth periods of the varieties.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.453-459
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• 2000

Three rice (Oryza sativa L. var Dong-Jin) mutants (DTR1, DTR2, DTR3) resistant to S-methyltryptophan (5MT) were selected by mutagenized M3 seeds. The frequency of chlorophyll mutations induced by the EMS (0.2%) treatment performed 2 hours after flowering is clearly higher than that induced by other treatments in M1 generation. Progeny obtained from the self-pollinating of 5MT-resistant lines segregated with 3 : 1 of resistant to sensitive ratio. Furthermore, the ratio of homozygote to heterozygote in 5MT-resistant plants of the M4 generation was 1：2. These results show that 5MT resistance was inherited as a single dominant nuclear gene. The resistance was also expressed in callus derived from seeds. Total free amino acid content in homozygous seeds of DTR1 and DTR2 showed about 1.7 fold-increased compared to the wild-type seeds. In particular, the levels of phenylalanine and Iysine were, respectively, 6.2 and 3.2 times higher than those in the wild-type seeds. However, seeds of DTR3 had lower levels of free amino acid than the wild-type seeds. This result indicate that these mutants as a significant step towards the production of new rice with balanced amino acid content.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.10
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• pp.1196-1203
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• 2012

This paper presents a study on the calibration of a C-band HPS(Hongik Polarimetric Scatterometer) system using the DMMCT(Differential Mueller Matrix Calibration Technique). For calibration of the polarimetric scatterometer system, a fully-polarimetric antenna pattern(magnitudes and phase-differences) of the antenna main-beam is measured using a conducting sphere at anechoic chamber. The polarimetric scatterometer system could be accurately calibrated after retrieving its distortions using the DMMCT. Unlike a single-polarimetric system, in a fully-polarimetric system, not only backscattering coefficients but also phase differences are important parameters. This calibrated HPS system can be used to measure accurate Mueller matrices of bare soil surfaces, rice paddies, and vegetation fields. The phase-difference parameters as well as the backscattering coefficients for co- and cross-polarizations can then be obtained. The accuracy of calibration was verified by comparing the measured backscattering coefficients with a scattering model. The measured polarization response of a plowed bare field was also compared with the polarization response which was synthesized using a polarimetric scattering model for verifying the calibration technique.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.235-240
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• 2002

We report the new method for the screening of genetically modified potato by competitive duplex-PCR using the potato specific single oligomer primer for the internal control and CaMV 35S promoter or NOS terminator specific primers. The single oligomer primer (rAGU4A) amplify the potato specific internal control band from the homozygous potato genomic DNA in the RAPD profiles of all analyzed potato varieties. The 530 bp internal control DNA was amplified independently to CaMV 35S promoter or NOS terminator DNA and identified as repetitive or microsatellite DNA of potato (AF541972). With this new technique, the transgenic potatoes which were transformed with vectors contained the different foreign genes are analyzed. In case of the commercialized transgenic potato varieties, 'Hew Leafs', those two genetic factors are used for promoter and terminator respectively So, this new PCR technique should be a promising method of cost effective and accurate screening for the commercialized GM potatoes on market.