eDNA(enviromental DNA)는 물, 토양, 대기 등 다양한 환경에서 채취한 생명체의 유전자 또는 그 유전자를 채취· 분석하는 기술로 생물을 직접적으로 관찰하지 않아도 생물이 남긴 흔적을 통해 종의 동정이 가능하다는 장점이 있다. 따라서, 야외에서 해충의 예찰조사, 외래종 감시 및 멸종위기종 모니터링 등 다양한 목적으로 활용될 수 있는 장점이 있다. 최근, 국제적으로 미생물, 수생태계 및 육상곤충 등 다양한 방면으로 eDNA가 연구되고 있으나 국내에서는 eDNA 연구가 수생태계, 미생물 등 일부 분야에서만 진행 중이며 육상곤충의 eDNA 연구는 미비한 실정이다. 따라서, 금번 연구에서 육상곤충에 활용할 수 있는 eDNA 실험방법 확립을 위해 기존문헌 참고 및 곤충분야에 접목하여 활용 가능한 육상곤충 샘플링 방법을 탐색 및 정리하였으며, 추후 eDNA 연구에 기반을 마련하고자 한다.
Background: Bird dog exercise (BDE) is one of the lumbar stabilization exercises that rehabilitate low back pain by co-contraction of the local and global muscles. Previous studies have reported the effect of various type of BDEs (for example, practicing the exercises on various surfaces and changing the limb movement) for muscle co-contraction.
Objects: This study aimed to investigate the effect of knee joint flexion position of the raised lower limb on abdominal and back muscle activity during BDE in patients with chronic low back pain (CLBP).
Methods: Thirteen males participated in this study (age: 32.54 ± 4.48 years, height: 177.38 ± 7.17 cm). Surface electromyographic (SEMG) data of the internal abdominal oblique (IO), external abdominal oblique (EO), lumbar multifidus (MF), and thoracic part of the iliocostalis lumborum (ICLT) were collected in two knee joint flexion positions (90° flexion versus 0° flexion) during BDE. The SEMG data were expressed as a percentage of root mean square mean values obtained in the maximal voluntary isometric contraction.
Results: Greater muscle activity of the IO (p = 0.001), MF (p = 0.009), and ICLT (p = 0.021) of the raised lower limb side and the EO (p = 0.001) and MF (p = 0.009) of the contralateral side were demonstrated in the knee joint flexion position compared to the knee joint extension position. Greater local/global activity ratios of the abdominal muscle (i.e., IO and EO) of the raised lower limb (p = 0.002) and the back muscle (i.e., MF and ICLT) of the contralateral side (p = 0.028) were also noted in the knee joint flexion position.
Conclusion: BDE with a knee joint flexion position might be recommended as an alternative lumbar stabilization exercise to enhance muscle activity in both the raised lower limb and the contralateral sides of the trunk for individuals with CLBP
The aging behavior of sintered Al composites with various ceramic contents was investigated. 2xxx series blended powder was used as the starting powder. Ceramic contents were 0wt.% and 5wt.%. The blended powders were compacted at 250MPa. The sintering process was performed at for 60min in a atmosphere. Each part was solution-treated at for 60min and aged at . The Rockwell hardness at the peak aging time increased with ceramic contents. However, the peak aging time at maximum hardness was reduced with increased ceramic contents.
Mechanical properties of 7xxx series Al metal matrix composite (MMC) powders containing different amounts of ceramic were investigated. The ceramic contents of the starting powders were 5 wt.% or 10 wt.%. The powders were uniaxially cold compacted using a cylindrical die with a compacting pressure of 250 MPa and were sintered at in a dry atmosphere for 60 min. For the heat treatment, sintered parts were solution treated at and aged at . Compression tests were conducted to reveal the effect of particle content on the mechanical properties of the composites. Fractography was examined using a scanning electron microscope.
Purpose - The Korean child welfare services may have different feelings between providers and users. Few studies on the child welfare service quality have been conducted and research on the coorientation model of child welfare services are nonexistent. We compared the perceptions of Korean child welfare service providers and users in this study. It will have many applications in the service quality fields by applying a coorientation model.
Research design, data, and methodology - In order to enhance user satisfaction with child welfare services, around 200 samples were carried out both in Busan and Kyungsangnamdo randomly. Seven point Likert scale was used in the questionnaire. Two measurements were made to evaluate the different positions on the part of child welfare service providers and users to assess their mutual orientation. Paired t-test verification was conducted for congruency analysis, and the verification of agreement and accuracy was analyzed by independent t-tests.
Results - We empirically examined the differences between the providers and the users stance. The results are as follows. We have verified the statistical significance of the difference in perception between providers and users. We also confirmed a degree of agreement, a degree of congruency, a degree of accuracy and a degree of meta agreement in the study. In the Korean child welfare service quality, the coorientation model of process quality appeared in the form of semi-dissensus, the coorientation model of results quality were shown in the form of ignorances and the coorientation model of physical environment quality were investigated in the form of semi-dissensus.
Conclusion - The study concluded that users need to understand more about the providers in order to enhance the coorientation model in process quality and physical environmental quality, and the providers need to persuade the users clearly about the positive factors. To enhance the coorientation model of the result quality, it can be misunderstood by guessing that the other party will positively evaluate it. Therefore, users believe that they need to talk more clearly to the provider about the results of the korean child welfare service quality to reduce misunderstandings and to understand each other about the resulting quality.
The Brown planthopper (Bph) is one of the most serious pests of rice affecting rice yield and quality throughout the country. Combining the Bph resistance in the existing quality japonica cultivars is an important breeding target in Korea. Wide crosses using several strains of AA-genome wild rices, O.rufipogon have been used to produce the primary germplasm which is highly resistant to Bph. By repeated backcrossing, the resistance gene was introgressed in the background of two japonica cultivars, Ilpum and Hwaseong. Among the advanced backcross progenies, the ten BC2F3 lines were identified as the highest resistance in the comparative Bph bioassay with other resistant sources. The 24 polymorphic markers spanning the twelve chromosomes were tested for association with marker genotypes and resistance/susceptibility reaction in the 80 BC2F3 lines, RM3748 on the chromosome 7 showed the highest association.
The objective of this study was to analyze the genetic diversity using SSR marker and investigate the fatty acid composition of perilla (P. frutescens var. frutescens) germplasm. Genetic diversity among 95 accessions, which consisted of 29 weedy types and 66 landrace accessions, was evaluated based on 12 SSR markers carrying 91 alleles. The mean values of observed (HO) and expected heterozygosities (HE) were 0.574 and 0.640, respectively, indicating a considerable amount of polymorphism within this collection. A genetic distance-based phylogeny grouped into two distinct groups, which were the landrace, moderate and weedy type, genetic distance (GD) value was 0.609. The physicochemical traits about crude oil contents and fatty acid compositions were analyzed using GC. Among tested germplasm, the total average oil contents (%) showed a range from 28.57 to 49.67 %. Five fatty acids and their contents in the crude oils are as follows: α-linolenic acid (41.12%-51.81%), linoleic acid (15.38%-16.43%), oleic acid (18.93%-27.28%), stearic acid (2.56%-4.01%), and palmitic acid (7.38%-10.77%). The average oil content of wild types was lower than landrace, and the oil content of middle genotype accessions was higher than other germplasm, but no significant variation between landrace and wild types was shown. Nevertheless, IT117174, landrace of Korea, was highest in crude oil content (47.11%) and linolenic acid composition (64.58%) among the used germplasm. These traits of the selected accessions will be helped for new functional plant breeding in perilla crop.
Rice grain number and grain dimensions including grain length-width ratio are critical components in determining the rice yield and quality. Manual or visual inspection for breeding lines and germplasm over these traits are time-consuming jobs. We developed and tested two algorithms for analysing grain number and dimensions (grain length, grain width) through image analysis system, Metamorph offline 7.0 (Molecular devices™). The algorithm for determining number of grain and shape constitutes a series of fragmentation processes including Shading, Color separate, Threshold, Euclidean, Dialate, Watershed Line, Arithmetic. When the six rice cultivars with different grain shapes were tested, there was no difference in the averaged values and distribution for the grain number and grain length between mannual and image analysis methods. However, image analysis resulted in the slightly increased values for grain width and more wider distribution whereas length/width ratio was slightly reduced by about 0.1, indicating that image analysis can be utilized more effectively and accuately in investigating the grain number and dimensions for sizable breeding lines.
Breeding the whole crop siliage rice cultivar basically requires priority in high biomass and grain yield and tolerance biotic and abiotic stresses. In this context, AA genome wild rices are potential resources to broaden genetic variability for whole crop silage cultivar. We have developed several introgression populations from crosses with three AA genome wild rices, O.glaberrima, O.rufipogon, and O.longistamina. Among these populations, the three BC4F8 near isogenic lines (NILs) derived from a cross of Milyang 23 and O.glaberrima(acc. 101154) could produce the high-yielding lines surpassing Milyang 23 by 20% in grain yield. Introgression lines from crosses with 4 accessions of O.rufipogon with japonica rices, Hwaseongbyeo and Ilpumbyeo had huge agronomic variability and very tall and vigorous lines possessing culm length of 125 ∼ 187cm were selected as promising potential parents to improve biomass of existing cultivars. These selections with high yield potential and biomass will be crossed to create another gene pool to combine high yield and biomass and anther culture breeding could be useful to develop genetically fixed F2 lines with both traits.
The Brown planthopper (BPH) is one of the most serious pests of rice affecting rice yield and quality throughout the country. AA genome wild rice, O.rufipogon is a useful source of insect resistance to BPH. To broaden the BPH resistance in the existing quality japonica cultivars, crossess were made between a highly susceptible quality rice cultivar, Ilpumbyeo, and five accessions (acc.106109, 106286, 106424,105908,80671) of O.rufipogon. Among 126 F8 RIL lines evaluated for Bph resistance at NICS, the highly resistant 22 introgression lines were identified and Ilpumbyeo*2/O.rufipogon (acc.105908) showed different genotype at the marker loci of Bph1, Bph18 and the resistance reaction to BPH in the BC1F2 population fitted to 3:1 segregation mode, indicating the possible new dominant resistance gene might be involved. Polymorphism between Ilpumbyeo and resistant line was low with 36 (27%) SSR markers among 130 markers detected. Currently mapping population of BC2F2 is established and SSR marker analysis will be carried out to find out the resistance loci.
Buckwheat (Fagopyrum esculentum Moench), one of the minor crops grown in Korea belonging to the Polygonaceae family, is an annual crop widely cultivated in Asia, Europe, and America and has a character of outcrossing and self-incompatibility. The objective of this study was to analyze the genetic variability, phylogenetic relationships and population structure of buckwheat landraces of Korea using SSR markers. Ten microsatellite markers have been detected from a total of 79 alleles among the 179 buckwheat accessions were collected from Korea. The number of allele per marker locus (NA) ranged from 2 (GB-FE-001, GB-FE-043 and GB-FE-055) to 31 (GB-FE-035) with an average of 7.9 alleles. GB-FE-035 was the most polymorphic with the highest PIC value 0.93. Major allele frequencies (MAF) for the 10 polymorphic loci varied from 0.12 to 0.97 with a mean allele frequency of 0.57. The expected heterozygosity (HE) values ranged from 0.05 to 0.94 with an average of 0.53. The observed heterozygosity (HO) ranged from 0.06 to 0.92 with an average of 0.42. The overall polymorphic information contents (PIC) values ranged from 0.05 to 0.93 with an average of 0.48. The landrace accessions of buckwheat used in the present study were not distinctly grouped according to geographic distribution. The study concludes that the results revealed genetic differentiation was low according to the geographic region because of outcrossing and self-incompatibility. We reported that our analyses on the genetic diversity of common buckwheat cultivars of Korea were performed by using of microsatellite markers.
The present study reports isolation and characterization of ten polymorphic SSR markers developed from common buckwheat (Fagopyrum esculentum Moench). These SSR markers produced a total of 59 alleles across 41 common buckwheat accessions with an average of 5.9 alleles per locus. Values for observed (HO) and expected (HE) heterozygosities ranged from 0.071 to 0.924 (mean=0.53) and from 0.073 to 0.902 (mean=0.412), respectively. At significance threshold (P<0.05), seven loci deviated from Hardy-Weinberg equilibrium (HWE), whereas significant linkage disequilibrium (LD) values were observed between 5 pairs of loci. These markers are currently being used for programming of the genetic conservation and classification of common buckwheat germplasm collection.
There are about 16 species included in Fagopyrum (Polygonaceae) genus and some of them have been found recently and named. Fagopyrum genus is generally divided into two major groups: cymosum and urophyllum group. This study is to analyze the genetic diversity of Fagopyrum genus, to compare with the phylogeny result of Fagopyrim using previous analysis results, and to provide the information of each species specific marker by executing the cross-amplification on 3 species and 2 sub-species among cymosum group and 5 species among urophyllum using 136 SSR markers newly developed from common buckwheat. Cluster analysis using UPGMA showed two main clusters, each of the cymosum and urophyllum group. This result agree well with the previous findings on species relationships in Fagopyrum using different method approachs. In cross species amplification, our results revealed significant transferability of F. esculentum microsatellites to the 4 cymosum species (96.3% in F. esculentum ssp. Ancestral, 61.0% in F. tataricum ssp. tataricum, 36.0% in F. tataricum ssp. potanini, 97.1% in F. homotropicum). However, the percentage of 136 SSR markers were amplified in the urophyllum species (50.7% in F. urophyllum, 50% in F. lineare, 60.3% in F. leptopodum, 66.9% in F. capillatum, 66.2% in F. gracilipes) was lower than cymosum species, except F. tataricum. In addition, we identified 61 species specific markers among each species. These results demonstrate wide potential applicabilityof these markers for the study of inter-specific genetic diversity as well as evolutionary relationships among cultivated and wild buckwheat.
Sequence-tagged site (STS) markers tightly linked to the bacterial leaf blight (BLB) resistance genes, xa5, xa13 and Xa21, were used in this study. A survey was conducted to find polymorphisms between the resistant and susceptible germplasm in rice. 500 of Korean varieties and 100 of landraces were evaluated in this study. STS marker, RG207 was used to having xa5 resistance gene of rice germplasm. 27 varieties of Korean germplasm showed resistant for xa5 gene. The RG136 an xa-13 marker resulted in a single band of approximately 1kb in all the rice accessions studied. In order to detect polymorphism, digestion of the polymerase chain reaction (PCR) product was performed using a restriction enzyme Hinf Ⅰ. The resistant lines resulted in two bands 0.5kb on digestion with Hinf Ⅰ, while the same enzyme did not digest the PCR product of susceptible lines. No polymorphism was detected in Korean varieties and landraces, indicating that they probably do not contain xa13 gene. pTA248 an Xa-21 marker detected a band of 1kb in the resistant lines and bands of either 750bp or 700bp in the susceptible lines. Among germplasm tested, there are no varieties and landraces with Xa21 resistant gene. The results of the germplasm survey will be useful for the selection of parents in breeding programs aimed at transferring these bacterial blight resistance genes from one varietal background to another.
Genetic background and phylogenetic relationships among 20 Korean wheat cultivars were assessed using microsatellites after amplifying with 13 SSR primer pairs. Average allele number per primer pair was 3.36. Genetic similarities for every pair of cultivars ranged from 0.42 to 0.97, with 0.69 of overall average. Korean cultivars were divided into two major groups based on microsatellite DNA polymorphisms. Group I consisted of relatively old cultivars developed until 1970s, and group II contained the recent cultivars developed during 1980s and 1990s. Amongst old elite cultivars/lines, ‘Yukseung 3’, ‘Norin 12’ and ‘Norin 72’ contributed most to the genetic background of cultivars belonging to group I, and ‘Norin 4’, ‘Norin 12’, ‘Norin 43’ and ‘Norin 72’ to group II, respectively. The phylogenetic relationship of Korean wheat cultivars was in accordance with the genealogical data of each cultivar. The genetic background of each cultivar was assessed from the point of breeding and germplasm management such as variety identification and duplicated accessions for assisting in developing a system for the registration of new variety based on the molecular characterization in future.