Variation and Trends of Irrigation Requirements of Rice Paddies in Korea

Nkomozepi, Temba Darlington,Chung, Sang-Ok Institute of Agricultural Science and Technology 2013 慶北大農學誌 Vol.31 No.4

Understanding the temporal variability of agricultural parameters derived from historical climate data is important for planning in agriculture. Therefore, this study assessed the magnitude and recent trends of the transpiration ratio defined as the crop water use per harvested yield for the period from 1980 to 2010. The crop water use was estimated using the Food and Agriculture Organization's Crop Wat model for eight administrative provinces in Korea. The temporal trends and spatial uncertainty were explored using the Mann-Kendall and Theil Sen's methods. The regional average rice yield was $6.31t\;ha^{-1}$(range 5.9 to $6.9t\;ha^{-1}$). The results showed that the rice yield in Korea increased by $26kg\;ha^{-1}yr^{-1}$. Overall, the regional average transpiration ratio was $1,298m^3t^{-1}$ (range 1,162 to $1,470m^3t^{-1}$). From 1980 to 2010, the transpiration ratio decreased by $8.2m^3t^{-1}$ (range 2.7 to $14.4m^3t^{-1}$), largely as a result of the increasing yield. The statistical approach to historical data used in this study also provides a basis for simulating the future transpiration ratio.

Effects of Flower Thinning Formulation on Activities of Digestive Enzymes and Acetylcholine Esterase in Honey bee Apis mellifera

Hemayet Jahan, S.M.,Shim, Jae-Kyoung,Son, Tae-Gwon,Jo, Jaedoo,Choi, Cheul,Lee, Kyeong-Yeoll Institute of Agricultural Science and Technology 2014 慶北大農學誌 Vol. No.

The effects of a newly developed flower thinning formulation (FTF) on the vitality of the honey bee Apis mellifera were examined by measuring the activities of various digestive enzymes in adult worker bees. First, direct spraying of the FTF solution did not cause any behavioral changes or lethal effects for the honey bees based on 24 h observation. Second, oral ingestion of a sugar solution containing the FTF did not produce any significant change in the activities of amylase, proteinases, lipase, or acetylcholine esterase (AChE) in the worker bees 6 h or 24 h after treatment. Meanwhile, a commercial formulation containing sulfur compounds showed slightly reduced activities for several digestive enzymes and AChE, although no behavioral disturbance. Thus, the results of the present study suggest that the FTF is not toxic for honey bees, in terms of contact and ingestion. Therefore, this newly developed FTF can be used for flower thinning without any detrimental effects on pollinating insects.

Effect of Soy Protein Diet on Mucosa Layer of Murine Small Intestine

Lee, Aeri,Lim, Jinkyu Institute of Agricultural Science and Technology 2014 慶北大農學誌 Vol.32 No.1

Soy and fermented soy are popular and recognized as a health food among Koreans. Since soy proteins are known to be protease resistant, even to pepsin and pancreatin, it is hypothesized that soy proteins may interact with the intestinal tract and trigger certain physiological reactions. To test this hypothesis, mice were fed diets supplemented with soy, Chunkukjang, or casein. The differentially expressed proteins were analyzed using 2-D gels and identified by peptide mass fingerprinting using mass spectrometry. The majority of the differentially expressed proteins could be functionally grouped into metabolic enzymes and calcium-binding proteins. The differential protein expression by the soy-fed groups was also verified based on a representative protein, tropomyosin, using a Western blotting analysis. In addition, the soy-fed groups exhibited a taller villi structure. Therefore, this study suggests that soy proteins can be an effective nutrient and physiological stimulant for the intestines.

Functional Components and Antioxidant Effects of Colored Onions

Yang, Xiao Nan,Xu, Enning,Park, Mi Jin,Ha, In Jong,Moon, Jin Seong,Kang, Young-Hwa Institute of Agricultural Science and Technology 2015 慶北大農學誌 Vol.33 No.2

The antioxidant capacities, total phenolic contents (TPC), and total quercetin contents (TQC) of a red (Chenjujuck), a yellow (Sunpower), and a white (Grasier) onion cultivar were determined in this study. Onion was separated into edible portion and dry skin. In the case of edible portion, the yellow onion had the highest antioxidant activity, followed by the red onion. The white onion showed neither antioxidant activity nor quercetin compounds. On the other hand, the dry skin of the red onion showed higher antioxidant activity than yellow onion skin. The white onion skin had slight antioxidant activity, low TPC, and no quercetin compounds. In addition, the flavonoid compounds of the edible portion and dry skins of these colored onions were analyzed by UFLC(ultra-fast liquid chromatography). The major compounds were quercetin 3,4-diglucoside and quercetin 4-glucoside in yellow and red onion edible portion, whereas the major compounds in yellow and red onion skins were quercetin 4-glucoside, quercetin, and quercetin 3,4-diglucoside.

Induction of Anticarcinogenic Enzymes by Dichloromethane-soluble Fraction of Physalis alkekengi var. francheti Hort. in Mouse Hepatoma Cells

Seo, JiYeon,Kim, Hyo Jung,Kim, Jong-Sang Institute of Agricultural Science and Technology 2014 慶北大農學誌 Vol.32 No.3

Physalis alkekengi var. francheti Hort. is known as an insecticide and traditional remedy for liver related diseases. Therefore, this study investigated the chemopreventive effects of extracts and several solvent fractions (n-hexane, dichloromethane, n-butanol, water) of Physalis alkekengi var. francheti Hort. First, their cytotoxicity and NQO1 activity were measured using an MTT assay, plus a quinone reductase [NAD(P)H dehydrogenase (quinone); NAD(P)H: (quinone acceptor) oxidoreductase, EC 1.6.99.2]-inducing activity assay was performed using cultured murine hepatoma cells (Hepa1c1c7) and its mutant cells(BpRc1). The reduction of electrophilic quinones by NQO1 is an important detoxification pathway and major mechanism of chemoprevention. When compared with the other solvent soluble fractions with different polarities, the dichloromethane fraction of Physalis alkekengi var. francheti Hort. showed a higher NQO1-inducing activity that was also dose-dependent. Moreover, the dichloromethane fraction of Physalis alkekengi var. francheti Hort. induced ARE-luciferase activities in HepG2-C8 cells that were generated by transfecting the ARE-luciferase gene construct, suggesting the Nrf2-ARE-mediated induction of anti-oxidative enzymes. In conclusion, the dichloromethane-soluble fraction of Physalis alkekengi var. francheti Hort. showed a relatively strong induction of detoxifying enzymes, thereby meriting further study to identify the active components and evaluate their potential as cancer preventive agents.

Effect of Polyphenol Oxidase Activity and Total Phenolic Content on Browning and Quality of Dried-Persimmon According to Maturity Degree of Astringent Persimmon

Jung, Kyung-Mi,Song, In-Gyu,Kim, Se-Jong,Lee, Sang-Han Institute of Agricultural Science and Technology 2015 慶北大農學誌 Vol.33 No.2

Hunter's color value "a" in dried-persimmon of table and full ripe fruit was higher than that in unripe fruit. In case of soluble solid content, full ripe fruit was $50^{\circ}Brix$, the highest degree, while unripe fruit was $40^{\circ}Brix$, the lowest degree. PPO activation of unripe fruit was 4.7, which was higher than table-ripe fruit (0.7) and full ripe (1.0). Polyphenol oxidase activation remained even while drying, but there was no difference in PPO activation degree as drying period increased. Total phenol content of unripe fruit was 101.4, which was higher than table-ripe fruit (57.5) and full ripe fruit (67.4). Total phenol content level increased as drying period increased, which was based on fresh weight. Hardness of unripe and table ripe fruit continued to decrease until three weeks during softening. After that, hardness was high and it started drying. However, in full ripe fruit, hardness increased after two weeks and softening was fast during the drying period, and its weight reduction rate was lower than that of unripe and table ripe fruit.

Identification of protease-resistant proteins from allergenic nuts using two-dimensional gel electrophoresis and mass spectrometry

Santos, Ilyn L.,Lee, Ju-Young,Youm, Yujin,Lim, Jinkyu Institute of Agricultural Science and Technology 2013 慶北大農學誌 Vol.31 No.2

Nuts are one of the most common sources of allergies in individuals of all ages. In order for a particular protein to render an allergic reaction, it must resist proteolytic digestion by intestinal enzymes. In this study, three well-known allergenic nuts, almonds, cashew nuts, and peanuts, were used as samples, and enzyme digestion with Bacillus protease and porcine pepsin was tested. A proteomic approach using two-dimensional gel electrophoresis and an MS/MS analysis was applied to visualize and identify the proteins that were resistant to enzyme digestion. Among the 150 protein spots tested, 42 proteins were assigned functions. Due to the lack of genomic databases, 41% of the identified proteins were grouped as hypothetical. However, 12% of them were well-known allergens, including AraH. The remainder were grouped as storage, enzymes, and binding proteins.

Effect of Different Fertilizer Ratio and Planting Dates on Growth and Acanthoside D content of Acanthopanax divaricatus and Acanthopanax koreanum

Lee, Jung Jong,Lee, Sang Hyun,Park, Jae Sang,Park, Chung Berm,Ahn, Young Sub,Lee, Sang Chul Institute of Agricultural Science and Technology 2013 慶北大農學誌 Vol.31 No.2

The cultivation methods of Acanthopanax in Korea need to be optimized. Hence, this study investigated the effect of different fertilizer ratios and planting dates on the growth and acanthoside D content of two (2) Acanthopanax species. The current recommended fertilizer rate of 10.5-8.5-8.5 $kg/ha^-$ ($N-P_2O_5-K_2O$, respectively) produced the best plant growth of Acanthopanax. For the first year, the acanthoside D content resulting from the 2P (2x phosphate) rate was higher than that from the other fertilizer ratios, yet there were no significant differences resulting from the various treatments for either Acanthopanax divaricatus or Acanthopanax koreanum. Similarly, for the second year, there were no significant differences in the acanthoside D content resulting from the various fertilizer ratios, although for both species the acanthoside D content resulting from the 2P rate was slightly higher than that from the other treatments. Therefore, the results indicated that doubling the amount of phosphate increased the acanthoside D content. Plus, the optimum planting date with respect to growth and productivity for Acanthopanax divaricatus was identified as April 15.

Optimization of Drying Conditions for Quality Semi-dried Mulberry Fruit (Morus alba L.) using Response Surface Methodology

Teng, Hui,Lee, WonYoung Institute of Agricultural Science and Technology 2014 慶北大農學誌 Vol. No.

Mulberry fruits were semi-dried using hot air ($60-100^{\circ}C$) or cool air ($20-40^{\circ}C$), and the effects of the drying temperature and processing time on the quality of the final dried mulberry fruits were investigated. Response surface methodology was employed to establish a statistical model and predict the conditions resulting in minimal loss of the total phenolic content (TPC) and ascorbic acid. Thus, using overlapped contour plots, the optimal conditions for producing semi-dried mulberry fruits, which reduced the moisture residue to 45% and minimized the nutrient losses of TPC and ascorbic acid, were determined for the hot-air process ($60.7^{\circ}C$ for 5.4 h) and cool-air process ($34.8^{\circ}C$ for 23.3 h). Plus, a higher drying temperature was found to lead to a faster loss of moisture and ascorbic acid, while the TPC was significantly decreased in the cool-air dried mulberry fruits due to the higher activity of polyphenol oxidase between 30 and $40^{\circ}C$.

Use of Androgenesis in Haploid Breeding

Yi, Gihwan,Kim, Kyung-Min,Sohn, Jae-Keun Institute of Agricultural Science and Technology 2013 慶北大農學誌 Vol.31 No.2

Haploids are plants with a gametophytic number of chromosomes in their sporophytes. Androgenesis occurs from asymmetric division of pollen grains into generative cells and vegetative cells, followed by re-entry of the vegetative cell during S-phase, which causes microspores progress into G2/M transition in culture. One of the most interesting features of haploids is the possibility to produce doubled haploid (DH) individuals. Doubled haploidy is extremely useful to plant breeders because it enables shortened breeding periods and efficiency in selection of useful recessive agronomic traits. Doubled-haploid technology is not only applicable to breeding, but also to transformation programs of desired genes. In addition to practical breeding programs, DH lines provide useful materials of fundamental genetics including exploitation of QTLs and genes conferred with various agronomic traits by establishing DH populations. This paper provides historical overviews on androgenesis and describes several mechanisms associated with pollen embryogenesis, including mode of actions in pollen embryogenesis, mechanisms of chromosome doubling and factors affecting androgenesis. We also discuss recent progress in application of haploids to breeding, genes associated with in vitro response and drawbacks to anther culture for application of doubled haploids in crop breeding.