• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.97-104
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• 2006

This study was conducted to investigate effect of temperature and NaCl on the seed germination and water absorption of Thuja orientalis. Seeds were treated with 0, 500, 1,000, 2,000 and 4,000ppm of NaCl and placed in different chambers at 15, 20, 25 and $30^{\circ}C$, respectively. And seed properties and relative water absorptions were analyzed. Germination decreased with the increase of both temperature and NaCl concentration, and especially the difference was obvious at $30^{\circ}C$. Dormancy and mortality increased with the increase of temperature in non-NaCl treatment. Two-way analysis of variance showed significant effects of temperature, NaCl concentration and interaction between temperature and NaCl concentration (p<0.001). Mean germination time increased with the increase of NaCl concentration at 15, 20 and $25^{\circ}C$ but decreased at $30^{\circ}C$ because the seeds were mortal by NaCl high concentration, Germination speed and germination performance index decreased with the increase of NaCl concentration. Those represented decreasing tendency with NaCl concentration but high positive correlation with germination. Relative water absorption decreased with the increase of NaCl concentration and represented high values at $15^{\circ}C$, and showed high positive correlations with germination, germination speed and germination performance index. It was reported that the high temperature and salinity were inhibitive factors of seed germination of Thuja orientalis.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.624-637
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• 2020

High-quality and high-phytonutrient watermelon fruits have strong market opportunities besides their health related benefits. Hence, investigating quality and nutritional related traits of watermelon genetic resources could provide important baseline data in breeding for increased lycopene content thereby increasing the marketability of watermelon. To this end, we have examined some fruit morphological traits and lycopene content of 105 genetic resources. Seeds, originally obtained from 22+ countries, were obtained from the National Agrobiodiversity Center, Jeonju, South Korea, grown in an experimental field and harvested at a fully mature stage. The size of pistil scar (SPS), the width of stripes (WS), weight of fruit (WF), length of fruit (LF), width of fruit (WIF), the thickness of pericarp (TP), soluble solids content (SSC), fruit shape in longitudinal section, ground color of skin, the intensity of the green color of skin, fruit shape at the apical part, grooving distribution, conspicuousness of stripes, and main color of the flesh were recorded on the field and inside laboratory and the lycopene was measured using spectrophotometric and HPLC methods. Watermelon fruits have shown a diverse morphological characters. Red and pink fleshed fruits dominated in the entire collections. Fruits with higher thickness of rind were found to exhibit less soluble solid content (SSC). Korean origin fruits were characterized by intermediate SSC while the United States of America (USA), Russia (RUS), Tajikistan (TJK), Turkmenistan (TKM), Taiwan (TWN), and Uruguay (URY) originated fruits had the highest SSC. The lycopene content varied between 41.37 and 182.82 ㎍/g, 2.81 and 163.72 ㎍/g, and 3.54 and 255.47 ㎍/g using HPLC, UV-Vis spectrophotometer, and microplate reader spectrophotometer, respectively. Red- and pink-fleshed fruits had the highest levels of lycopene content compared to the yellow- and orange-fleshed. Lycopene content had a significant positive correlation with SSC, however, no correlations were detected between lycopene and other quantitative fruit morphological characters. Our study demonstrated high diversity exists in fruit morphological traits and lycopene content of the germplasm collections which provide beneficial baseline data for a future breeding program and utilization of watermelon germplasm collections in gene banks for the maintenance and improvement of the current levels of production, marketability, and health-related benefit of watermelon fruits.

• Journal of Life Science
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• v.12 no.3
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• pp.256-263
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• 2002

This study was carried out to estimate the degree of heterosis and heterobeltiosis, and the heritability and genetic correlation in F$_1$hybrid produced by reciprocal crosses between two six-rowed hulled barley (Gangbori and Olbori) and three six-rowed naked barley (Saechalssalbori, Saessalbori, and Moodeongssalbori). Heterosis was observed positively in traits such as cults length, spike length, awn length, leaf length, leaf width, number of spikes per plant, number of grains per spike, and 1000 grain weight. Heterosis and heterobeltiosis from the crosses with hulled barley as a material parent showed higher performance in culm length, leaf length, leaf width, number of spike per plant, number of grains per spike. The hulled grain characteristics is dominant over the naked one. The highest heritability was confirmed in leaf width with a value of 94.5% and overall high heritability was observed in most traits with the range from 76.7% to 94.5%. In an analysis of correlation coefficient, higher genetic correlations were observed between leaf length and number of spikes per plant(0.970), between cults length and number of grains per spike(0.963), and between awn length and leaf length(0.862) in the forward crosses in which hulled barley was maternal. In the reverse crosses, higher genetic correlation was observed between culm length and spike length(0.926), between awn length and leaf length(0.922), and between number of spikes per plant and number of grains per spike(0.713).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.265-269
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• 2021

This study was conducted to provide primary data through analysis of zoysia grass genetic resources to develop grass cultivars with beneficial novel properties. Zoysia grass (Zoysia. spp) is native to Korea, and is mainly propagated through stolons. However, since seed coat treatment technology was developed, the breeding of sexually reproductive grass variants has become possible, necessitating characterization of the floret appearance rate in the secured zoysia grass genetic resource before developing sexually reproductive cultivars. In this experiment, 549 grass lines were examined, revealing that florets appear in only 43 lines (7.81%). Survival rates after transplantation, and stolon generation rates displayed a significant positive correlation (Rho = 0.44). Survival rates after transfer, and rates of stolon production displayed very low correlations with floret appearance (Rho = -0.11 and Rho = -0.06). No significant results were obtained in 43 lines that displayed >20% floret appearance. To breed sexually reproductive grass variants, it is thus necessary to secure more genetic resources, considering the low rate of floret appearance. Finding traits that predict floret appearance at an early stage is also required.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.134-151
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• 2024

Salmonella spp. is among the most important water-borne and food-borne pathogens and is one of the most common causes of human gastroenteritis and diarrheal diseases globally. In this study, Salmonella spp. isolated from food, environmental samples, and patients with food poisoning or diarrhea were investigated Salmonella serovars, antibiotic resistance using Vitek2, and genetic characteristics through pulsed-field gel electrophoresis (PFGE). Salmonella spp. of 339 strains, including 26 strains from food or environmental samples and 313 strains from patients, were isolated from Jeju Island of South Korea between 2020 and 2023. The monthly number of isolated Salmonella spp. gradually increased from March, with the highest number being in August. No significant differences in Salmonella spp. isolated from patients according to gender was observed. However, Salmonella spp. was most frequently isolated from people aged 70 years or older and least frequently isolated from those between ages 10 and 19 years. Salmonella spp. isolated from food or environmental samples were distributed among eight different serovars and the main serovars were identified in the order of S. Bareilly (26.9%), S. Rissen (23.1%), and S. Thompson (19.3%). Salmonella spp. isolated from patients were distributed among 27 different serovars and the main serovars were identified in the order of S. Bareilly (31.0%), S. Typhimurium (24.6%), and S. Enteritidis (11.5%). The main cause serovars of Salmonella spp. outbreaks are S. Bareilly, S. Enteritidis, S. Thompson. Antibiotic resistance tests indicated resistance to various antibiotics and some Salmonella spp. exhibited multidrug resistance. Salmonella spp. showed various genetic correlations among the 17 serovars. These results indicate that they can be used as basic data for epidemiological investigations by predicting the appearance of Salmonella spp. and providing a scientific basis.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.703-710
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• 2005

Data from Hanwoo steers and bull calves were analyzed to see the phenotypic and genetic relationships between carcass traits from four different covariance models. Four models fit test station and test period as fixed effect of contemporary group and sire as random effect assuming paternal half-sib relationships among animals. Each model fits one of linear covariate (s) of different slaughter end points-age at slaughter in the first order, age at slaughter in the first and second order, slaughter weight or back fat thickness at 12-13th rib of cold carcass. Age at slaughter in its second order was not significant. Age at slaughter accounted for signifi- cant amount of genetic variances and covariances of carcass traits. Heritability estimates of back fat thickness, rib eye area, carcass weight, marbling score and dressing percentage were 0.34, 0.22, 0.24, 0.42 and 0.18, respectively at constant age basis. The genetic correlation between carcass weight and the other variables were all positive and low to high in magnitude. Genetic correlations between back fat thickness and rib eye area and between marbling score and dressing percentage were low but negative. Variance and covariance structure between these traits were shifted to a great extent when these variables were regressed on slaughter weight or on back fat thickness. These two covariates counteracted to each other but they adjusted each carcass variable or their interrelationship according to differential growth of body components, bone, muscle and fat. Slaughter weight tended to decrease genetic variances and covariances of carcass weight and between component traits and back fat thickness tended to increase those of rib eye area and between rib eye area and carcass weight.

• Korean Journal of Poultry Science
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• v.16 no.2
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• pp.73-81
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• 1989

This study was conducted to estimate heritabilities, genetic and phenotypic correlations on economic traits in layers. The data analysis were the records of 351 pullets in S. C. W. Leghorn and 326 pullets in R. I. Red from March 1, 1980 to July 31.1981. The results obtained are summarized as follows：1 The average body weights at the first egg, 300 and 500 days of age were 1, 409, 1, 602 and 1, 709g S. C. W. Leghorn, and 1, 965, 2, 305, and 2, 479g in the R. I. Red, respectively. The age at first egg of the S. C. W, Leghorn and R. I. Red were 156 days and 163 days, respectively. The number of egg produced by the S. C. W. Leghorn and R. I. Red to 300 days and 500 days of age were 101.18, 214.39, and 101.05, 214.93, respectively. The egg weight at first egg, 300 and 500 days of age were 41.93, 57.65 and 60.33g in the S. C. W. Leghorn and 41.52, 57.62 and 60.57g in the R. I. Red, respectively. 2. The heritability estimates based on the variance of sire and dam components were 0.402-0.612 and 0.275-0.458 in the S. C. W. Leghorn, 0.309-0.523 and 0.134-0.380 in R. I. Red for body weight； 0.167 and 0.139 in the 5. C. W. Leghorn, 0.169 and 0.095 in the R.1. Red for age at first egg：0.214-0.139 and 0.336-0.341 in S. C. W Leghorn, 0.137-0.259 and 0.024-0.102 in the R. I. Red for number of egg production； 0.537-0.769 and 0.374-0.686 in the S. C. W. Leghorn, 0.519-0.631 and 0.116-0.365 in the R. I. Red for egg weight, respectively. 3. The genetic correlation coefficients of economic traits were as follows： In the S. C. W. Leghorn and R. I. Red , the coefficients between body weights and age at the first egg, 0.328-0.426 and 0.186-0.244：between body weights and number of egg production, -0.666--0.498 and -0.452--0.073：between body weight and egg weight, 0.384-0.774 and 0.126-0.612； between age at first egg and number of egg production, -0.639--0.452 and -0.754--0.320； between age at first egg and egg weight, 0.475-0.705 and 0.021-0.605； between number of egg production and egg weight, -0.623--0.355 and -0.861--0.327, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.485-495
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• 2020

Melon (Cucumis melo L.), one of the most important fruit crop species, is cultivated worldwide. In this study, a total of 206 melon accessions conserved at the National Agrobiodiversity Center (NAC) in RDA were characterized for nine morphological characteristics according to the NAC descriptor list. In addition, to confirm the genetic composition of each melon accession, genetic profiling was performed using 20 SSR markers. Among the 206 melon accessions, 159 (77.2%) were collected from Asia. The color of fruit flesh and skin were mostly 'white' (56.0%) and 'green' (49%), respectively. Days to female flowering (FD) and maturity (MD) of the accessions ranged from 58 to 72 and 17 to 63, respectively. The fruit length and width of the accessions ranged from 6.0 to 29.3 and 3.6 to 17.2 cm, respectively. The sugar content (SU) ranged from 2.5% to 13.2% with an average of 7.0%. In correlation analysis, SU showed positive and negative correlations with MD and FD, respectively. The accessions were classified into four clusters by cluster analysis. From the results of genetic profiling using 20 SSR markers, three accessions (K189118, K100486, and K190292) were expected to be inbred lines among 206 melon accessions. These results could expand the knowledge of the melon germplasm, providing valuable material for the development of new melon varieties to suit consumer tastes.

• Korean Journal of Plant Resources
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• v.36 no.1
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• pp.1-14
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• 2023

This study measured the antioxidant activity and phytochemical content of 192 Boehmeria nivea var. tenacissima (Gaudich.) Miq. collected from six regions in order to identify the possibility of its industrial application. Two antioxidant activity assay (DPPH radical scavenging activity and ABTS radical scavenging activity) and two phytochemical content assay (total polyphenol content (TPC) and total flavonoid content (TFC)) of 192 samples were analyzed. The results showed that the DPPH radical scavenging activity of 192 samples was ranged from 0.02 to 1.35 mgAAE/g, and among them, the samples collected from Goheung (0.53 ± 0.37) and Ulleungdo (0.52 ± 0.28) showed the highest activity. The ABTS radical scavenging activity was showed the ranged from 0.07 to 1.81 mgAAE/g, and the samples collected at Ulleungdo (0.47 ± 0.36) showed the highest activity. The total polyphenol content of 192 samples was 18.6 to 234.8 ugGAE/g, and the samples collected at Mokpo (93.4 ± 34.7) and Jindo (90.4 ± 24.5) showed the highest content. The total flavonoid content was 0.10 to 1.22 mgQE/g and the samples collected at Ulleungdo (0.49 ± 0.31) showed the highest content. In the correlation analysis, there was no significant relationship between the environmental conditions and the antioxidant activity. The total polyphenol content showed a positive correlation with daily temperature difference, and negative correlation with average wind speed and average humidity, and total flavonoid content showed negative correlations with the average temperature, maximum temperature, and minimum temperature. This result can be used as a basic data establish the cultivation conditions of B. nivea var. tenacissima (Gaudich.) Miq. as a functional raw material to increase the usefulness of B. nivea var. tenacissima (Gaudich.) Miq..

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.276-284
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• 2023

Nitrogen is a major and essential macronutrient for plant growth and development. However, excessive nitrogen application can lead to ecological pollution or greenhouse gas emissions, consequently resulting in climate change. In this study, we used 153 genetic resources of rice to evaluate the effects of the levels of nitrogen application on grain yield and yield-related traits. Significant differences were noted in the yield and yield-related traits of genetic resources between two nitrogen application levels, namely, 4.5 kg/10a (NN: normal nitrogen condition) and 9.0 kg/10a (LN: low-nitrogen condition). Among the tested traits, days to heading (DTH), clum length (CL), grain yield per plant (GYP), number of panicles per plant (NPP), and number of spikelets per panicle (NSP) decreased by 1.8 to 17.9% when the nitrogen application levels decreased from NN to LN. The 1,000-grain weight (TWG) and percentage of ripened grain (PRG) increased by 2.6 to 11.2% under these conditions. Based on nitrogen application levels, two-way analysis of variance (ANOVA) demonstrated significant differences in GYP, NPP, and PRG but not in NSP and TGW. NPP exhibited negative correlations with NSP (-0.44) and TGW (-0.44), and TGW displayed a negative correlation with PRG (-0.34), whereas, GYP exhibited a positive correlation with PRG (0.37) and NSP (0.38). A similar pattern was recorded under the LN condition. NPP, TGW, and PRG were clustered as PA (principle axis) 1 under the LN condition by factor analysis. NSP and GYP were clustered as PA (principle axis) 2. These results demonstrated NPP and NSP as the primary factors contributing to the decrease in grain yield under LN conditions. In conclusion, we selected eight genetic resources that exhibited higher GYP under both NN and LN conditions with higher NPP or NSP. These genetic resources can be considered valuable breeding materials for the adaptation of plants to nitrogen deficiency.