• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.25-25
• /
• 2022

Drought becomes frequent and severe because of continuous global warming, leading to a significant loss of crop yield. In soybean (Glycine max [L.]), most of quantitative trait loci (QTLs) analyses for drought tolerance have conducted by investigating yield changes under water-restricted conditions at the reproductive stages. More recently, the necessity of QTL studies to use physiological indices responding to drought at the early growth stages besides the reproductive ones has arisen due to the unpredictable and prevalent occurrence of drought throughout the soybean growing season. In this study, we thus identified QTLs conferring wilting scores and moisture contents of soybean subjected to drought stress in the early vegetative stage using an recombinant inbred line (RIL) population derived from a cross between Taekwang (drought-sensitive) and SS2-2 (drought-tolerant). For the two traits, the same major QTL was located on chromosome 10, accounting for up to 11.5% of phenotypic variance explained with LOD score of 12.5. This QTL overlaps with a reported QTL for the limited transpiration trait in soybean and harbors an ortholog of the Arabidopsis ABA and drought-induced RING-D UF1117 gene. Meanwhile, one of important features of plant drought tolerance is their ability to limit transpiration rates under high vapor pressure deficiency in response to mitigate water loss. However, monitoring their transpiration rates is time-consuming and laborious. Therefore, only a few population-level studies regarding transpiration rates under the drought condition have been reported so far. Via employing an Arduino-based platform, for the reasons addressed, we are measuring and recording total pot weights of soybean plants every hour from the 1^st day after water restriction to the days when the half of the RILs exhibited permanent tissue damage in at least one trifoliate. Gradual decrease in moisture of soil in pots as time passes refers increase in the severity of drought stress. By tracking changes in the total pot weights of soybean plants, we will infer transpiration rates of the mapping parents and their RILs according to different levels of VPD and drought stress. The profile of transpiration rates from different levels of severity in the stresses facilitates a better understanding of relationship between transpiration-related features, such as limited maximum transpiration rates, to water saving performances, as well as those to other drought-responsive phenotypes. Our findings will provide primary insights on drought tolerance mechanisms in soybean and useful resources for improvement of soybean varieties tolerant to drought stress.

• Research in Plant Disease
• /
• v.28 no.3
• /
• pp.143-151
• /
• 2022

In order to investigate the cause of wilting symptoms in red pepper field of Korea, the frequency of occurrence of red peppers showing wilting symptoms was investigated in pepper cultivation fields in Goesan, Chungcheongbuk-do for 5 years from 2010 to 2014. There was a difference in the frequency of wilting symptoms depending on the year of investigation, but the frequency of occurrence increased as the investigation period passed from June and July to August. During this period, Ralstonia solanacearum causing the bacterial wilt was isolated at a rate four times higher than Phytophthora capsica causing the Phytophthora late blight. In wilted peppers collected in Goesan of Chungbuk and Andong of Gyeongbuk in 2013 and 2014, R. solanacearum and P. capsici were isolated from 20.3% and 3.8% of the total fields, respectively. In the year with a high rate of wilting symptoms, the average temperature was high, and the disease occurrence date of the bacterial wilt, estimated with disease forecasting model, was also fast. The inconsistency between the number of days at risk of Phytophthora late blight and the frequency of occurrence of wither symptoms is thought to be due to the generalization of the use of cultivars resistant to the Phytophthora late blight in the pepper field. In our study, the wilting symptoms were caused by the bacterial wilt caused by R. solanacearum rather than the Phytophthora late blight caused by P. capsica, which is possibly caused by increasing cultivation of pepper varieties resistant to the Phytophthora late blight in the field.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.49 no.2
• /
• pp.107-116
• /
• 2023

In this study, to explore the possibility of using discarded by-products of corn as a wrinkle-improving functional material, the active ingredient contained in each part including kernel, cob, husk, and silk of 10 varieties of chodang and waxy corn was identified and the content was analyzed to suggest the possibility of corn by-products as upcycling materials. As a result of evaluating the collagen synthesis efficacy of extracts by part, the cob in chodang and waxy corns showed significant activity at 100 ㎍/mL concentration of 176.5 and 140.0%, respectively. The LC-MS/MS qualitative analysis resulted in the identification of 18 components in the cob, of which N, N'-diferuloylputrescine (DFP) was selected as an active ingredient, and the quantitative analysis was conducted by variety and part. As a result, DFP was confirmed only in the cob and kernel, and it was most frequently detected in the cob of the Goldsugar of chodang corn (39.6 ㎍/g) and Daehakchal of waxy corn (38.4 ㎍/g). The cob is a by-product left over from grain removal, and is expected to create new added value as a material that promotes collagen synthesis. Through this study, we propose the possibility of using discarded cob as a wrinkle-improving functional material.

• Journal of Conservation Science
• /
• v.7 no.1
• /
• pp.9-18
• /
• 1998

There are about 1470 stone-cultural properties in Korea which have been registered and protected by the government. Representative of them are pagoda, stupa, stone-buddha, stele support of banner pole and stone-lanterns. Most of them have been exposed to and weathered by natural environments. Stone-cultural properties are destroyed and/or destructed mostly by weathering and its related features of rocks. Therefore, it is necessary to conduct geological studies on the weathering phenomena and related features as well as characteristics of the rock itself must be done for the conservation. Thus geological investigation should include detail measurements, rock varieties and phases, structural lineaments of the rock, cause and degree of weathering, degree and patterns of crack development structural stability, identification of reusable parts for restoration, geomorphological characteristics of the site, and etc. The interaction among these factors must be investigated and analyzed, which must be used as basic data to establish the guideline of conservation and to plan for repair and/or restoration. The conservation plan should involve parts to be repaired, method of repair, type of cementing material, the characteristics of rock phases to be supplemented, method for maintaining structural stability, and method to delay or to prevent the rock weathering.

• Korean Journal of Mineralogy and Petrology
• /
• v.35 no.4
• /
• pp.431-445
• /
• 2022

A quantitative phase analysis method of X-ray powder diffraction was studied to determine the mineral content of clay-rich rocks practically as well as effectively. For quantitative X-ray powder diffraction analysis of the clay-rich rocks, it is necessary to prepare whole-rock powder samples with a random orientation by side mounting method. In addition, for the identification of the clay minerals in the rock, it is required to prepare an oriented mount specimen with a clay particle size of 2 ㎛ or less, ethylene glycol treatment, and heat treatment. RIR (reference intensity ratio) and Rietveld method were used for the quantitative analysis of the clay-rich rocks. It was possible to obtain the total clay and the non-clay minerals contents from the whole-rock X-ray diffraction profiles using the RIR values. In addition, it was possible to calculate the relative content of each clay mineral from the oriented X-ray diffraction profiles of the clay particle size and assign it to the total clay. In the Rietveld method of whole-rock X-ray diffraction, effective quantitative values were obtained from the Rietveld diffraction patterns excluded the region of less than 10 degrees (2θ). Similar quantitative values were shown in not only the RIR but the Rietveld methods. Therefore, the analysis results indicate a possibility of a routine quantitative analysis of clay-rich rocks in the laboratory. However, quantitative analysis of clay minerals is still a challenge because there are numerous varieties of clay minerals with different chemical and structural characteristics.

• Journal of Life Science
• /
• v.28 no.3
• /
• pp.357-360
• /
• 2018

This study developed a method to minimize rice damages and enhance timely control by accurately classifying Whitebacked Planthopper (WBPH). The body size of the 1st-3rd instar was 1.5-2 mm, and the body size of the 4-5 instar was 2.5-3.5 mm. In the third instar, the ratio of the front wing bud and the back wing-bud was 1:1. The fourth instar occupied 3/4 of the front wing-bud, and the 5th instar showed that the front wing-bud covers the back wing-bud. It was confirmed that the 1st instar does not have a sensory plate, the 2nd instar has 2-3, the 3rd instar has 4-5, the 4th instar has 6-9, the 5th instar has 10-15, and the adult instar has 15-20 sensory plates. The female spawning organs were reddish when the spawning horn was inserted. WBPH showed that the larvae of 2-3 larvae most actively feed on rice, and the damaged area was the stem of rice near the ground. In addition, a partial black wound was observed after the feeding. WBPH-susceptible 'Chucheong' was yellowish, and early growth was slower than that of 'Cheongcheong', which was resistant; moreover, a difference between susceptibility and resistance was observed. The identification of the number of such wounds in the bioassay will be a better basis for understanding the difference in susceptibility between WBPH strains and cultivars. These results will be used as basic data for cultivating the WBPH-resistant varieties of rice.

• Korean Journal of Plant Taxonomy
• /
• v.37 no.4
• /
• pp.545-563
• /
• 2007

The investigated vascular plants of Dok-do island were confirmed that consisted of 46 species, 1 subspecies, 1 varieties in total of 48 taxa growing spontaneously. 1 taxa of Pteridophyta, 36 taxa of Dicotyledon and 11 taxa of Monocotyledon identified. In 48 identified taxa in this study, total 13 taxa included Orobanche coerulescens Stephan, Fallopia sachalinensis (F. Schmidt) Rouse Decr., Lonicera insularis Nakai identified according to the Korean plant taxa for environmental assessment. Planting species were about 10 taxa included Pinus thunbergii Parl., Hibiscus syriacus L. and etc. Four species confirmed in this study such as between Chenopodium virgatum Thunb. and Chenopodium album L., Echinochloa crusgalli (L.) P.Beauv. and Echinochloa crusgalli var. oryzicola (Vasinger) Ohwi. were doubt on identification in taxonomic entity due to morphological characteristics. The dispersion type of Do-kdo plants were anemochore 31 taxa, zoodchore 8 taxa, hydrochore 2 taxa and the others by artificial means.

• Korean Journal of Plant Resources
• /
• v.23 no.5
• /
• pp.480-485
• /
• 2010

This study reports on the morphological characteristics and distribution for conservation and practical use in the Korean Peninsula of Chrysosplenium flaviflorum through a comparison with relative species. The morphological characters that were newly investigated in this study included subhypogaeus stolons and glabrous on the surface of leaves. The former has not been described by any taxonomist who had previously treated this species with the exclusion of Hara. Despite this, the latter is a very important key to using the identification of varieties of Ser. Pilosa though there were no descriptions which included Ohwi. C. flaviflorum Ohwi which was endemic and known to be distributed only in the northern area of the Korean Peninsula, was also observed in the Gapyeong-gun, Gyeonggi-do, Cheorwon-gun, Gangwon-do, and Yeongdonggun, Chungcheongbuk-do middle area since the latest collection report in 1943. There is a requirement for further study to be conducted on the distribution and management by designation for the Special Plant Species by the Korean Ministry of Environment.

• Korean Journal of Microbiology
• /
• v.51 no.4
• /
• pp.382-388
• /
• 2015

Eleven protease-producing bacteria were isolated from the organisms' external shells and the inorganic materials collected from intertidal zone of Jeju Island, Republic of Korea. The samples were diluted serially, inoculated on Zobell agar plates with 1% skim milk and incubated at $20^{\circ}C$. Clear zone forming colonies were selected as protease-producing bacteria and each strain was identified based on the phylogenetic analysis with their 16S rDNA sequences. Strains JJM125, JJM129, YG47 and YG49 belong to the marine bacterial genus Pseudoalteromonas; strain JJM122 belong to the genus Microbulbifer; strains YG51, YG52, YG62 and YG63 belong to the genus Vibrio; and strain YG65 belong to genus Bacillus. Hence, the present study suggests that these protease producing bacteria could be further used to develop new varieties of protease with various biotechnological applications.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.58 no.3
• /
• pp.283-291
• /
• 2013

Rice varieties with suitable flour-making quality are required to promote rice processed-food industry and boost rice consumption in Korea. 'Namil (SA)-flo1' is an advanced mutant line with floury endosperm which shows good flour-making quality under dry-milling process. Genetic analysis was carried out to localize the chromosomal region responsible for the floury endosperm of 'Namil (SA)- flo1'. By using 94 F2 progenies, which were derived from 'Namil (SA)-flo1' ${\times}$ 'Milyang 23', floury grains percentage was investigated as phenotypic data, and genotyping was conducted with 54 SSR markers. Association analysis showed that the target genetic region for floury endosperm is on middle-low region of chromosome 5. Through further association analysis with increased number of SSR markers on chromosome 5, we found that genotypic variation in RM164 explains 79.7% of the variation in floury grains percentage of F2:3 seeds. The floury endosperm locus was localized on 17.7-20.7 Mbp region of chromosome 5 and will be further analyzed for fine mapping and gene identification.