Ecological characteristics of the brown alga Ishige okamurae Yendo in its natural habitat at Janggam, Shinan on the southwestern coast of Korea were investigated from March 2023 to February 2024. The population of I. okamurae formed extensive patches along the shoreline. Environmental factors such as seawater temperature, pH, salinity, and dissolved oxygen were monitored during this study. Growth and maturation of the I. okamurae population were assessed using both qualitative and quantitative methods. This alga showed a peak growth in October when the seawater temperature was 19.9°C. It had a mean length of 7.6±1.4 cm, a mean density of 4,466.6±288.9 ind. m-2, and a mean biomass of 663.9±85.3 fresh-wt. m-2. The effective cumulative temperature required for the alga’s maturation was estimated based on growth data with a biological zero temperature of 9.2°C. Sporangia were observed from June to November when seawater temperatures ranged from 20.5°C to 14.0°C. Unilocular sporangia first appeared in June, followed by simultaneous appearance of unilocular sporangia and plurilocular sporangia from July to September. From October to November, only unilocular sporangia were observed. Thallus development began at temperatures above 9.2°C. Maturation required approximately 577 degree-days for unilocular sporangia and 801 degree-days for plurilocular sporangia.
본 연구의 목적은 재즈 역사에서 인정받고 있는 베이스 연주자 레이 브라운의 즉흥연주 중 투필 베이스 라인을 분석하여 그 특징을 알아보고 이를 통해 , 현대 재즈 연주자들에게 그의 특징인 투 필 베이스 라인을 적용 및 재현하여 재즈의 새로운 시각을 제공하는 데에 있다. 이를 위해 연구방 법으로 재즈 음악에서 가장 기본적인 트리오 구성(피아노, 베이스, 드럼)에서 베이스의 워킹 베이 스 라인 중 레이 브라운의 연주곡 6곡을 선정하여 투 필 베이스 라인의 리듬과 하모니를 심층 분석 하였고 그 결과를 다른 3곡에 적용시켜 레이 브라운 스타일의 예제를 만들었다. 본 연구에서 레이 브라운의 선율적 특징과 화성적 특징, 그리고 리듬적 특징, 테크닉적인 특징을 분석하고 적용하였 고, 선율적 특징은 콜 앤 리스폰스 주법을 사용하였고, 화성적 특징은 가이드 톤 라인을 사용하여 도미넌트 모션을 4번째 박자에 사용하였다. 리듬적 특징으로는 투 필 베이스 라인에서 2분음표로 만 연주하는 것이 아니라 2, 4마디에서는 포비트 워킹 베이스 라인을 연주하여 리듬에 안정감을 더한다는 결과를 도출해 내었다. 이러한 레이 브라운의 고찰이 객관적인 자료로 남아 투 필 베이 스 라인에 대한 기준을 제시해 다른 재즈 베이스 연주자들에게 도움이 됐으면 하고, 솔로 라인이 나 포 비트 워킹 베이스 라인, 솔리스트로서의 발전에 도움이 될 수 있기를 기대하는 바이다.
Habitat environment and food sources of fish, benthic macroinvertebrates, and brown trout (Salmo trutta) downstream of Soyang River Dam were analyzed. Water temperature at the site where brown trout was identified ranged from approximately 12.4 to 13.4°C, confirming that this environment could provide an optimal water temperature for the growth of brown trout. Most of the riverbed structures at this site had a high proportion of cobble and pebble substrates. Brown trout constituted less than 5% of the total fish population, more abundant in the upstream. The total lengthweight relationship of brown trout showed a parameter b value of 3.234, with the condition factor (K) increasing with length. Dominant benthic macroinvertebrates were Limnodrilus gotoi and Chironomidae spp. (non-red type). Stomach content analysis indicated that brown trout primarily consumed aquatic insects (R.A., 73.8%), non-insects (R.A., 23.3%), ground insects (R.A., 2.7%), and fish (R.A., 0.2%, TL: 246 mm). Correlation analysis revealed a positive relationship between total length and species preferring flowing water (p<0.05) and a negative relationship of total length with species favoring low-flow, sandy habitats (p<0.05). Larger brown trout showed active feeding behavior and resilience to flow speed and riverbed structure. The primary food source for the largest brown trout (TL: 246 mm) was Hypomesus nipponensis. Future analyses should include brown trout with a total length of 30 cm or more. Given that samples were limited, comprehensive population management will require ongoing research.
Pseudolithoderma subextensum is a crustose brown algal species in the family Lithodermataceae and order Sphacelariales. This species is distributed in several regions across the world including, Europe, Western Atlantic, Middle East and Asia (Hong Kong and Japan). Recent floristic surveys along the Korean coastal shores have revealed new records of encrusting brown algae. In this study, we report P. subextensum as a new record from Korea. Morpho-anatomical and molecular studies on Ralfsia-like specimens from Korea identified some of them as P. subextensum. Pseudolithoderma subextensum is characterized by dark chestnut brown crust with a hypothallial basal layer and erect perithallial filaments, tufts of hairs occasionally arising from the basal layer, several discoid shaped chloroplasts per cell, plurangia arising terminally on erect filaments and without sterile cells, and unangia arising terminally on erect filaments, elongated cylindrical and without paraphyses. Phylogenetic analyses based on COI-5P (545bp) reveal that P. subextensum are nested within Lithodermataceae and forms the same clade with P. roscoffense. The genetic divergences for COI-5P between them is 24.5%.
Fluorescent bacteria were isolated from sporocarps that browned into various mushrooms during survey at places of the production in Korea. We examined the pathogenicity, biodiversity, and genetic characteristics of the 19 strains identified as Pseudomonas tolaasii by sequence analysis of 16S rRNA and White Line Assay. The results emphasize the importance of rpoB gene system, fatty acid profiles, specific and sensitive PCR assays, and lipopeptide detection for the identification of P. tolaasii. As a result of these various analyses, 17 strains (CHM03~CHM19) were identified as P. tolaasii. The phylogenetic analysis based on the 16S rRNA gene showed that all strains were clustered closest to P. tolaasii lineage, two strains (CHM01, CHM02) were not identified as P. tolaasii and have completely different genetic characteristics as a result of fatty acids profile, specific and sensitive PCR, lipopetide detection, rpoB sequence and REP-PCR analysis. Pathogenicity tests showed 17 strains produce severe brown discolouration symptoms to button mushrooms and watersoaking of sporophore tissue within three days after inoculation. But two strains did not produce discolouration symptoms. Therefore, these two strains will be further investigated for correct species identification by different biological and molecular characteristics.
본 연구는 소양강댐 하류에서 서식하는 생태계교란 생물 종인 브라운송어와 그 먹이원으로 이용되는 저서성 대형무척추동물에 대한 파악을 위해 2022년부터 2023년까지 총 8회에 걸쳐 소양강댐 하류(St.1~St.3)와 지류 (St.4)에 대해 브라운송어와 공서종, 브라운송어의 위 내용물, 저서성 대형무척추동물의 종조성 및 기능군 분석을 실시하였다. 저서성 대형무척추동물의 경우, 하루살이목에서 가장 많은 분류군이 확인되었으며(27.1%), 그 중 붙는 무리(CL)와 헤엄치는 무리(SW)가 높은 비율을 차지하는 것으로 확인되었다. 브라운송어 채집 결과, 전장은 26∼246mm까지 총 105개체가 채집되었으며, 전장-체중 관계의 매개변수 b값이 3을 초과하여 안정적인 성장이 이루어지는 것으로 확인되었다. 브라운송어의 위 내용물에 대한 먹이원 분석 결과, 빙어(0.2%, TL: 246mm)와 육상곤충(2.7%, TL: 154mm, 183∼185mm)을 섭식한 개체는 매우 적었으며 상대적으로 전장이 큰 개체에서 확인 되었다. 대부분 수서곤충(73.8%)과 물 속에서 서식하는 비곤충류(23.3%)를 섭식하는 것으로 나타났다. 브라운 송어의 전장에 따른 먹이 섭식 패턴을 파악하기 위해 위 내용물에서 확인된 종들과의 상관분석을 실시한 결과, 브라운송어의 먹이원 중 유수성 환경 선호 종들의 경우 전장과 양의 상관관계(p<0.05)를 나타낸 반면, 모래 기질 이하의 흐름이 적은 서식처를 선호하는 종들의 경우 전장과 음의 상관관계(p<0.05)를 나타냈다.
최근 이상기후 및 기후변화로 인해 농작물 병해충 발생이 증가하고 발생양상 또한 다양해지고 있으며, 국제 무역 및 해외 여행객 증가로 인한 외래 병해충 유입 위험성이 높아지고 있는 추세이다. 특히 대표적인 비래해충 중의 하나인 벼멸구(Nilaparvata lugens Stål, 1854)의 발생 범위, 출현율 및 빈도수가 꾸준히 증가하여 피해를 호소 하는 농가들이 많아진 반면, 이들에 대한 대응책은 피해발생의 불규칙성, 이전 자료의 부족 및 불명확성으로 인해 미비한 실정이다. 본 연구에서는 이러한 문제를 대비해 벼멸구의 온도발육모형을 이용하여, 기상자료, NCPMS와 더불어 연발생 횟수와 분포 가능 범위 및 발생 시기를 예측하였다. 또한, 벼멸구의 발생량이 많았던 충남 예산, 경남 사천, 진주의 최초발생일, 최초비래일, 최고발생일, 발생최성일 기준으로 각각 발육영점온도 및 유효적산온도를 적용하여 세대별 발생시기를 예측하였다. 최초발생일과 최초비래일은 예산 7월 9일, 7월 16일, 사천 7월 2일, 7월 19일, 진주 7월 26일, 7월 26일로 나타났으며, 최초발생일과 최초비래일 사이를 초발생일 로 적용하면 다음세대 발생이 실제 조사한 지역별 최고발생일인 예산 9월 7일, 사천 8월 9일, 진주 8월 8일과 근접 한 시기로 추정되어 효과적임을 알 수 있었다.
The small brown planthopper (SBPH), Laodelphax striatellus, is a major insect pest for the rice plants. SBPH is also a known vector of rice stripe virus (RSV), which causes severe yield losses in rice crops throughout the East Asia. RSV is persistently transmitted by SBPH and can also be transmitted to offspring through transovarial transmission. SBPH is known to migrate from China to the west coast of the Republic of Korea (ROK). The study investigated the impact of temperature on the acquisition and transmission of RSV by SBPH in ROK, which is expected to experience increased migration and emergence of SBPH due to climate change. The results revealed that the acquisition and transmission rates of RSV were higher at 27°C compared to 24°C, with rates of 100% and 78.3%, respectively. However, at 30°C, the acquisition and transmission rates of RSV was decreased. The results suggests that temperature can impact the transmission of RSV by SBPH. To investigate this further, SBPH adults were fed on RSV-infected plants and infection rates were compared across various tissues, including the head, salivary glands, midgut, Malpighian tubules, ovary, and hindgut. Results showed that at 36 hours post-infection, RSV was highly detected in the Malpighian tubules, ovary, and hindgut. At 48 hours post-infection, RSV was also detected in the thorax. These results suggest that the transmission rates of RSV in SBPH increase with temperature between 24-27°C, but decrease at 30°C, indicating that the vectorial capacity of SBPH for RSV decreases above a certain threshold.
Milky white spots appeared on red bean leaves in a red bean cultivation area located in Jangyeon-myeon, Goesan-gun, Chungbuk Province. After culturing the pathogen in PDA medium, their morphology was observed, and their genes were BLAST-searched in the National Center for Biotechnology Information (NCBI). The pathogen was identified as a fungus called Rhizopus arrhizus. As a result of reinoculating the isolated pathogen on red beans, the same symptoms as those in the isolated leaves occurred. Characteristic colonies of R. arrhizuson PDA medium initially showed a bright color and then changed to dark gray over time, with mostly spherical sporangia. The sporangiospores were spherical or elliptical, mostly irregular, and small in size. Therefore, based on these results, this disease has not yet been reported in red beans and was called red bean brown leaf blight caused by Rhizopus arrhizus A. Fisch (syn. R. oryzae).
Brown rice has various health benefits; however, it is more difficult to cook and has a harder texture as compared to milled rice. In this study, the effect of the sous-vide cooking method on starch retrogradation and textural properties of brown rice was investigated by comparative analysis with conventionally cooked brown rice based on moisture content assay, evaluation of the textural property analysis, and differential scanning calorimetry (DSC). The results of the study are as follows: First, the moisture content of sous-vide cooked brown rice was higher than in the conventionally cooked brown rice. Second, the sous-vide cooked brown rice has lower hardness, higher adhesiveness, and lower retrogradation enthalpy during storage than conventionally cooked brown rice. Finally, the retrogradation properties of cooked brown rice during storage were analyzed by DSC. The enthalpy increased more rapidly in the case of conventional cooked brown rice, reaching 1.58 J/g after 3 days of storage. This indicated that sous-vide cooking is effective in preventing retrogradation of rice during storage.
Reported positive ion fragmentation of phenolic acid derivatives in rice (Oryza sativa L.) were summarized based on the literature. A total of eight phenolic acids (4 derivatives of ferulic acid, 3 derivatives of sinapic acid and p-coumaric acid) were isolated and identified from rice (raw and steamed) using UPLC-DAD-QToF/MS. Results revealed that 6-O-feruloylsurose was the major component with 3'-O-sinapoylsucorse being tentatively identified in Oryza sativa L. for the first time as a new hydroxycinnamoyl derivative in rice grains. In our study, raw brown rice had the highest phenolic acid contents with Samkwang showing higher phenolic acid content than Saeilmi and Sindongjin (12.41 vs. 7.89 and 3.10 mg/100 g dry weight, respectively). Of all varieties, brown rice had higher phenolic acid contents than white rice. These contents decreased considerably when rice was steamed whereas, p-coumaric acid and ferulic acid contents were increased. Additionally, contents of rice (raw and steamed) can be used as a fundamental report for new rice varieties.
Biocide dichlofluanid breaks down quickly and accumulates easily in sediment, potentially causing a persistent impact on various marine organisms. We analyzed the potential toxicity of dichlofluanid on major aquaculture species in Korea, Undaria pinnatifida. Female gametophytes of U. pinnatifida were exposed to dichlofluanid at concentrations of 0, 1, 2, 4, 8, 16, and 32 mg L-1, and their survival and relative growth rate were analyzed. The no observed effect concentration (NOEC), lowest observed effect concentration (LOEC), and median lethal concentration (LC50) for female gametophyte survival were determined as 1, 2, and 10.82 (95% CI: 8.87-13.23) mg L-1, respectively. The NOEC, LOEC, and median effective concentration (EC50) for relative growth rate were 1, 2, and 6.58 (95% CI: 6.03-7.17) mg L-1, respectively. Female gametophytes of U. pinnatifida were expected to experience toxic effects at concentrations above 2 mg L-1 of dichlofluanid. These research findings are expected to serve as important reference data for evaluating the toxicity effects of U. pinnatifida in its early life stages when exposed to dichlofluanid.
The fungus Alternaria alternata, responsible for causing brown to black spotting on numerous fruits and vegetables globally, was identified in 2022 as the causative pathogen of brown spot disease in potatoes in Korea. In pursuing potential inhibitors against A. alternata growth, we evaluated 15 mushroom culture filtrates: eight from Trametes spp. and seven from Polyporus spp., known for their antibacterial and anticancer properties. Antifungal activity was assessed by exposing each filtrate to A. alternata on a paper disc. Four filtrates displayed inhibitory action against the fungus, albeit with mild effects. Our findings highlight the potential of Trametes and Polyporus fungi as emerging antifungal candidates, offering promise in preventing potato brown spots.
Insects, including aphids, caterpillars, and beetles, have a significant impact on biodiversity, ecology, and the economy by consuming various plant tissues like leaves, stems, and fruits, leading to issues such as holes, defoliation, and impaired growth. Consequently, our study's primary goal was to establish a model system capable of identifying and tracking insects, covering aspects like their behaviors, movements, sizes, and patterns. Our research has successfully produced a 3D monitoring system specifically designed for continuous insect tracking by applying it to brown planthopper. This technology allows for in-depth exploration of insect behaviors and their interactions with plants and crops. The potential applications of this technique are highly promising, offering valuable assistance to researchers in unraveling insect behavior and ecological dynamics and driving further advancements in these crucial research areas.
매년 국내로 비래해 오는 해충인 벼멸구는 그 기원이 중국 또는 중국 남부일 것으로 예상해왔으나, 이에 대한 유전학적 근거는 Mun et al. (1999)에 의해 제시된 세 가지 COI haplotype 비교가 유일하다. Mun et al. (1999)은 국내에 서 확인된 두 가지 haplotype 유형이 인도차이나반도 이남의 균일한 한 가지 haplotype 집단 유형과 중국에서 확인 된 또 다른 haplotype 집단 유형임을 근거로 국내 벼멸구의 기원을 중국으로 특정한 바 있다. 본 연구는 국내 및 동남아시아 5개국(부탄, 미얀마, 캄보디아, 라오스 및 태국)으로부터 직간접적으로 확보한 개체들을 대상으로 GBS (genotyping by sequencing) 및 NGS 기법을 통해 PCA를 포함한 다양한 집단유전학적 분석을 수행하였다. 그 결과 인도차이나반도의 벼멸구 집단은 크게 북부와 남부로 나뉘며, 국내 개체들은 북부에 비해 남부(캄보디 아, 태국)에 더 가깝다는 사실을 확인하였다. 따라서 벼멸구의 국내 비래는 중국으로부터의 기원 이전에 장마전 선이 형성될 무렵부터 인도차이나반도 남쪽의 고온다습한 서풍이 남남서풍으로 바뀌면서 중국 내륙을 거쳐 국내로 비래하는 경로를 따르는 것으로 보인다. 하지만 태안의 개체 중에는 인도차이나반도 집단들의 외군으로 확인되는 개체가 있었고, 이는 인도차이나반도 외의 샘플링되지 않은 다른 지역에서도 벼멸구가 국내로 비래할 수 있다는 가능성을 제시하였다. 따라서 국내로 유입되는 벼멸구의 유전적 기원을 확인하기 위해서는 인도차이 나반도 남쪽 지역에서 시작한 동아시아 여름 몬순의 바람이 한국으로 도착하는 경로에 위치한 다른 지역에서의 추가적인 샘플링 및 지속적인 관심과 추적이 필요할 것이다.
A new brown variety of Flammulina velutipes, referred to as ‘Asakgold,’ was bred by crossing two monokaryons isolated from the “Geumhyang2ho” and “Garlmoe” varieties. The pileus color of the new variety is light brown and its shape is hemispherical. During bottle cultivation, the period necessary for mycelial growth was 40 days, 9 days for primordia formation and 15 days for fruiting body growth. The total cultivation period was 64 days, which was similar to that of the control variety “Yeoreumhyang1ho.” The pileus of the new variety was similar and the stipe was thinner and longer than that of the control. The number of valid stipes per bottle was 495, which was 37 % higher than that of the control (362), and the yield was 214 g, 16 % higher than that of the control (185 g). The -glucan content was 28.69 %, which was observed to be 1.6 times more than that of the control.