• 제목/요약/키워드: Natural variation

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RAPD를 이용한 들깨 유전자원의 유전적 변이 분석 (Analysis of Genetic Variation of Perilla Germplasm Using RAPD)

  • 김도훈;양보경;김현경;김나영;정순재;김익수;남재성;이재헌;정대수
    • Journal of Plant Biotechnology
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    • 제30권3호
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    • pp.221-226
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    • 2003
  • Genetic variation of Perilla germplasms was investigated using RAPD markers. Forty-two Perilla frutescens lines and cultivars collected form locals were subjected to RAPD analysis using 220 primers. Among them only 13 primers showed polymorphic bands and these 13 primers provided a total of 144 bands, consist of 115 polymorphic and 29 monomorphic ones. The polymorphic bands were subjected to phylogenetic analysis using UPGMA and maximum parsimony (MP) methods. In the UPGMA method, similarity coefficiency of 42 Perilla frutescens lines and cultivars ranged from 0 to 0.7842. The dendrogram of 42 lines and cultivars obtained through UPGMA method resulted in two major groups, and the similar clustering pattern was found by MP method, suggesting Perilla germplasms utilized in this study truly can be divided into two major groups. Although the two major groups were consistent roughly with their phenotypes (under of node, weight of 1,000 grains, and oil content), in detail, much inconsistency also was present.

적도수렴대의 위치변화에 따른 북동태평양 적도해역의 부유성 유공충 군집의 계절변동 (Seasonal Variation of Planktonic Foraminifera Assemblage in response to Seasonal Shift of Inter-Tropical Convergence Zone in the Northeastern Equatorial Pacific)

  • 이유리;;우한준;김형직;이성주;김부근
    • Ocean and Polar Research
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    • 제36권4호
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    • pp.437-445
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    • 2014
  • A time-series sediment trap was operated at a water depth of 4950 m from July 2003 to May 2004 at KOMO station ($10^{\circ}30^{\prime}N$, $131^{\circ}20^{\prime}W$) in the northeastern equatorial Pacific, with the aim of understanding the temporal variation of planktonic foraminifera assemblages in response to the seasonal shift of Inter-Tropical Convergence Zone (ITCZ). A total of 22130 planktonic foraminifera specimens belonging to 30 species and 11 genera were identified, which shows a distinct seasonal variation with high values (125~288 specimens $m^{-2}day^{-1}$) in the winter to spring (December-May) and low values (16~23 specimens $m^{-2}day^{-1}$) in the fall (September-November). In addition, seasonal ecological differences of foraminifera assemblages are distinctly recognizable: omnivorous foraminifera occurred predominantly during the summer season, whereas herbivorous ones were dominant during the winter season. Such seasonal variations correspond to the seasonal shift of the ITCZ. Enhanced occurrence of herbivorous species during the winter-spring season seems a result of surface water mixing generated by the southward shift of the ITCZ. The increase in omnivorous species during the summer season may be due to the northward movement of the ITCZ caused by weakened wind speed, resulting in the intensification of water column stratification and nutrient-poor environment. A significant reduction of planktonic foraminifera specimens during the fall is attributed to heavy precipitation and reduction in light intensity.

QTL Analysis of Soybean Seed Weight Using RAPD and SSR Markers

  • Chung, Jong-Il;Ko, Mi-Suk;Kang, Jin-Ho
    • Plant Resources
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    • 제3권3호
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    • pp.184-193
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    • 2000
  • Soybean [Glycine max (L.) Merr.] seed weight is a important trait in cultivar development. Objective of this study was to identify and confirm quantitative trait loci (QTLs) for seed weight variation in the F2 and F2:3 generations. QTLs for seed weight were identified in F2 and F2:3 generations using interval mapping (MapMaker/QTL) and single-factor analysis of variance (ANOVA). In the F2 plant generation (i.e., F3 seed), three markers, OPL9a, OPM7a, and OPAC12 were significantly (P<0.01) associated with seed weight QTLs. In the F2:3 plant row generation (i.e., F4 seed), five markers, OPA9a, OPG19, OPL9b, OPP11, and Sat_085 were significantly (P<0.01) associated with seed weight QTLs. Two markers, OPL9a and OPL9b were significantly (P<0.05) associated with seed weight QTLs in both generations. Two QTLs on USDA soybean linkage group C1 and R were identified in both F2 and F2:3 generations using interval mapping. The linkage group C1 QTL explained 16% of the variation in seed weight in both generations, and the linkage group R QTL explained 39% and 41% of the variation for F2 and F2:3 generation, respectively. The linkage group C2 QTL identified in F2:3 generation explained 14.9% of variation. Linkage groups C1, C2 and R had previously been identified as harbouring seed size QTLs. The consistency of QTLs across generations and populations indicates that marker-assisted selection is possible in a soybean breeding program.

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Habitat selectivity of fresh water fishes of two second-order tropical streams in Tigray, Northern Ethiopia

  • Tesfay, Solomon;Teferi, Mekonen;Tsegazeabe, Haileselasie Hadush
    • Journal of Ecology and Environment
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    • 제43권1호
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    • pp.73-83
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    • 2019
  • Background: Habitat selectivity and ecology of freshwater fishes were studied in two selected streams and their junction point which consist a total of 39 microhabitats. The aims of this study were to describe the habitat preference and its availability to fish assemblage, as well as ecology, habitat use, and habitat characteristics. Methods: We collected fish with backpack electrofishing three times during August 2013, December 2013, and March 2014. Using a variation partitioning approach of R software, we studied the relationship of fish abundances with stream type, habitat type, and abundance of key macroinvertebrate taxa. Results: A total of 6554 fishes representing four species belonging to the family Cyprinidae were caught. A higher total fish abundance was recorded from Gereb Tsedo (4870; 74.3%) than from Elala stream (1684; 25.7%). Taking both streams together, the overall total relative fish abundance was significantly higher in pools (53%) than in runs (35%) and in riffles (12%) at P < 0.05. Species-wise comparisons showed that 71%, 15%, 13%, and 1% of the pool fish community were occupied by Garra blanfordii, Garra ignestii, Garra dembecha, and Garra aethiopica, respectively. Stream type, habitat type, and key macroinvertebrate taxa each explained a significant proportion of the variation in fish abundance. Based on the variation partitioning approach, fish abundance was higher in Gereb Tsedo stream (P < 0.01). Moreover, fish abundance increased with pool habitat type (P < 0.01) and with availability of key macroinvertebrate taxa (P < 0.01). Conclusion: Fish abundance differed between stream types, among habitats and among key macroinvertebrate taxa availability. Among the factors, habitat type was the most important driving factor behind variation among fish abundances, and pool supports the highest fish abundance.

Analysis of Genetic Variation in Botrytis cinerea Isolates Using Random Amplified Polymorphic DNA Markers

  • Choi, In-Sil;Kim, Dae-Hyuk;Lee, Chang-Won;Kim, Jae-Won;Chung, Young-Ryun
    • Journal of Microbiology and Biotechnology
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    • 제8권5호
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    • pp.490-496
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    • 1998
  • Random amplified polymorphic DNA (RAPD) markers were used to survey genetic variability among 34 Botrytis cinerea isolates from nine different host plants in Korea. For RAPD analysis, 115 arbitrary decamer primers were initially screened for polymorphic major DNA bands with 11 representative B. cinerea isolates. Eleven primers that initially detected polymorphisms were tested a second time with additional 23 isolates of B. cinerea as well as one isolate of Botrytis squamosa as an outgroup. The RAPD analyses revealed that all isolates except one showed different molecular phenotypes. Dendrograms obtained from dissimilarity matrices using the unweighted paired group method of arithmetic means (UPGMA) showed the 36.4% to 90.0% similarity among all B. cinerea isolates. The B. squamosa isolate showed the least similarity to all B. cinerea isolates. The cluster analyses indicated no correlation among all the characteristics examined including molecular phenotypes, host and geographic origins, year of isolation, or pathogenicity. The RAPD data suggest that a high level of genetic variation exists among Korean populations of B. cinerea and it seems to be caused by heterokaryosis among preexisting molecular phenotypes.

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타원형 실린더의 각도 변화가 사각 밀폐계 내부의 자연대류 현상에 미치는 영향 (The Effect of Variation in Angle of the Elliptic Cylinder on Natural Convection in a Square Enclosure)

  • 손용진;하만영
    • 설비공학논문집
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    • 제30권2호
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    • pp.58-67
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    • 2018
  • This study investigated the effect of variation in the angle of the elliptic cylinder as well as the presence of circular cylinder on natural convection inside a square enclosure. The Rayleigh number was varied between $10^3$ and $10^6$, and the Prandtl number was fixed to 0.7. In the present study, the angle of the elliptic cylinder was changed from $0^{\circ}$ to $90^{\circ}$, and the perimeter of the elliptic cylinder was same as that of the circular cylinder. The immersed boundary method was used to capture the virtual wall boundary of the inner cylinder. With the increasing angle of the elliptic cylinder, the surface-averaged Nusselt numbers on the cylinder and the enclosure increased. In the Rayleigh number range considered in the present study, the surface-averaged Nusselt number on the elliptic cylinder over = $45^{\circ}$ was higher than that of the circular cylinder. The effect of elliptic cylinder's angle on natural convection in the enclosure was analyzed according to the flow and thermal fields, and the distributions of the Nusselt number.

회전하는 유체이송 외팔 파이프의 동특성 해석 (The Dynamic Characteristics of Rotating Cantilever Pipe Conveying Fluid)

  • 윤한익;손인수
    • 한국소음진동공학회논문집
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    • 제13권1호
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    • pp.26-32
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    • 2003
  • The vibrational system of this study is consisted of a rotating cantilever pipe and the flow in the pipe. The equation of motion is derived by using Lagrange equation. The influences of the rotating angular velocity and the velocities of fluid flow in the pipe have been studied on the dynamic characteristics of a rotating cantilever pipe by numerical method. The tip-amplitude of axial vibration and maximum tip-deflection of axial direction of cantilever pipe are directly proportional to the velocity of fluid and rotating angular velocity of pipe In the steady state. respectively The bending tip-amplitude of cantilever pipe is inversely proportional to the velocity of fluid in the steady state. When the rotating angular velocity is 5 rad/s, the velocity of fluid increase with increasing the natural frequency of axial vibration at second mode and third mode, but the natural frequency axial direction of first mode is decreased. The natural frequency of lateral direction is decreased due to increase of the rotating angular velocity. It identifies that the Influence of velocity of fluid give much variation lower mode of vibration in lateral direction. And the Influence of velocity of fluid give much variation higher mode of vibration in axial direction.