• Title/Summary/Keyword: morphological variations

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Comparison of bivalves of Family Pinnidae from Southern Vietnam: A morphometric approach

  • Silina, Alla V.
    • The Korean Journal of Malacology
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    • v.27 no.4
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    • pp.345-351
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    • 2011
  • Comparison of different morphological characteristics of bivalves is very useful for distinguishing species. Therefore, this study used a morphometric approach to document patterns of phenotypic change through the specimens of family Pinnidae inhabiting the bottom sediments at the coasts of An Thoi Archipelago (south-eastern Gulf of Thailand), in that way excluding intraspecific variations among different populations along a wide geographical range. It was revealed that individuals determined as Pinna trigonium separated from specimens of Pinna nigra and Atrina vexillum at high level, but P. nigra and A. vexillum were the single species A. vexillum, as it is assumed now. Also, it was found that both groups of P. trigonium individuals and A. vexillum specimens divided into tree subgroups unified the specimens with the similar morphometric parameters: small, medium and large within the populations, though there were no evident divisions into subgroups in the size distributions of the populations. In addition to the interspecific morphological variations, the species also showed significant intraspecific morphological variations even in the same population. Most probable reason for the appearance of the intraspecific morphological variations and division of all specimens into size-specific subgroups in the population is the fact that the growth of Pinnidae bivalves is not isometric.

Genetic Diversity and Morphological Variations of Goosegrass [Eleusine indica (L.) Gaertn] Ecotypes in Malaysia

  • Saidi, Nazreen;Kadir, Jugah;Hong, Lau Wei
    • Weed & Turfgrass Science
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    • v.5 no.3
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    • pp.144-154
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    • 2016
  • Goosegrass [Eleusine indica (L.) Gaertn] has been a nuisance to growers in Malaysia due to its increased resistance to commercial herbicides, rapid growth and dissemination, and interference with agricultural practices. In the course of developing an apt integrated management to control goosegrass, more information of this weed is needed. The aim of this study was to look into variations among the goosegrass ecotypes sampled throughout Malaysia from the aspects of genotype and phenotype. Sequence-related amplified polymorphism (SRAP) markers were employed in investigating the genetic diversity and relationships among the 18 goosegrass ecotypes. Consequently, 5 primer combinations amplified 13 fragments with the polymorphism rate of 69.23%. At 74% similarity, the ecotypes were clustered into 6 groups. Phenotypic variability of the goosegrass ecotypes was assessed by observing their morphology, growth and seed traits. Goosegrass ecotypes were sorted into 3 major groups at the genetic distance (DIST) of 0.37. Concurrences of the evaluated genetic distance, ecotypes with the closest and most distant relationships were assembled together in Group I which showed high variation even among ecotypes in the same group. Results obtained thus implied high molecular and morphological variations of the goosegrass ecotypes in Malaysia.

Effect of Morphological variations on the Biodegradability of linear and star shaped PGCL (선형과 스타형 Poly(glycolide-co-$\varepsilon$ -caprolactone)의 형태학적 미세 구조변화가 분해성에 미치는 영향)

  • 조도광;박준욱;임승순;김수현;김영하
    • Proceedings of the Korean Fiber Society Conference
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    • 2001.10a
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    • pp.179-182
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    • 2001
  • 지방족 폴리에스터는 보통 의료용 고분자 및 환경분해성 고분자로 알려져 왔으며, 이에 따라 지방족 폴리에스터와 그의 공중합물, 그리고 다른 상용고분자와의 블렌드들의 분해 메카니즘에 관한 연구 보고가 이루어져 왔다. 일반적으로 결정성 고분자의 분해성은 일차적인 화학구조외에도 결정의 size나 perfactness, 결정화도 또는 배향도와 같은 미세 구조에 의해서도 크게 영향을 받는다. (중략)

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THE EFFECTS OF X-RAY IRRADIATION ON THE GERMINATION AND GROWTH OF SEEDLING IN GinKgo biloba L.

  • You, Young-Soo;Kim, Yong-Kwan
    • Journal of Korean Society of Forest Science
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    • v.8 no.1
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    • pp.140-148
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    • 1968
  • Ginkgo biloba L., which was distributed in Korea, was x-rayed with 100, 250, 500, 1000, 2000, 6000R. The results of responses about germination, morphological variations in seedling and early stage growth may be summarized as follows : 1. The germination percent was decreased with X-ray increasing dose from 500R except the slight stimulation of 100R. 2. The germination $LD_{50}$ seemed to be 765R. 3. The seedling height was depressed significantly but only slightly in 100R. 4. The loaf index was increased proportionally to high dose but T/R ratio was reduced apparently. 5. The dry or fresh weight decreased from 250R. It was highly significant except 100R. 6. Many morphological variations were indicated in plants.

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Morphological Variations Between Cultivated Types of Perilla Crop and Their Weedy Types in Korea and Japan

  • Jung, Ji Na;Heo, Kweon;Kim, Myong Jo;Lee, Ju Kyong
    • Korean Journal of Breeding Science
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    • v.40 no.4
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    • pp.361-370
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    • 2008
  • In order to better understand the morphological differentiation of the two cultivated types of Perilla crop and their weedy types in Korea and Japan, we studied the variation of 62 accessions by examining 15 morphological characteristics. By using ANOVA (one-way analysis of variance), we determined that var. frutescens and var. crispa showed significant morphological differences in terms of plant height and seed weight. Furthermore, cultivated var. frutescens and var. crispa could also be clearly discriminated from one another using PCA (principal component analysis). Specifically, quantitative and qualitative characteristics such as plant height, seed weight, degree of pubescence, shape of leaf, color of leaf, fragrance of plant, color of flower, color of stem and seed size greatly contributed to differences seen in the positive and negative direction on the first axis. In our study, most accessions of cultivated var. frutescens and those of its weedy type could be clearly discriminated from one another, however, most accessions of cultivated and weedy types of var. crispa were not clearly discriminated by the ANOVA and PCA analyses. These results indicated that cultivated var. frutescens can be considered to be a domesticated form, while the cultivated var. crispa can not be considered to be a domesticated form in Korea and Japan. It is our belief that our results concerning the morphological variations among cultivated types of Perilla crop and their weedy types in Korea and Japan will help ensure the long-term success of breeding programs and maximize the use of the germplasm resources in Korea.

Two Zopheridae (Coleoptera: Tenebrionoidea) Species New to Korea and a Key to the Korean Genera

  • Lee, Seung-Gyu;Kim, Il-Kwon;Lim, Jongok
    • Animal Systematics, Evolution and Diversity
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    • v.33 no.3
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    • pp.189-194
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    • 2017
  • The Zopheridae Solier consisting of members from three previous families, Zopherinae Solier, Monommatinae Blanchard and Colydiinae Erichson, is considered the taxonomically most challenging group, and comprises more than 1,700 described species worldwide. The members of Zopheridae represent diverse morphological variations, and are difficult to separate morphologically from other tenebrionoid families. Two Zopheridae genera, Colobicus Latreille and Lasconotus Erichson, are identified for the first time in Korea, and two wood-boring species, C. hirtus (Rossi) and L. niponicus (Lewis), are newly reported in the Korean fauna. A key to the genera of Korean Zopheridae, and diagnoses, habitus photographs, and illustrations of diagnostic characters of the two species are provided.

Taxonomy of the Genus Sargassum (Fucales, Phaeophyceae) from Korea I. Subgenus Bactrophycus Section Teretia (한국산 갈조식물 모자반속(Sargassum)의 분류 I. Bactrophycus아속 Teretia절)

  • Oak, Jung-Hyun;Lee, In-Kyu
    • ALGAE
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    • v.20 no.2
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    • pp.77-90
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    • 2005
  • Eight species of Sargassum subgenus Bactrophycus section Teretia were collected from the coasts of Korea: S. confusum C. Agardh, S. pallidum (Turner) C. Agardh, S. muticum (Yendo) Fensholt, S. thunbergii (Mertens ex Roth) Kuntze, S. fulvellum (Turner) C. Agardh, S. hemiphyllum (Turner) C. Agardh, S. nipponicum Yendo, and S. miyabei Yendo. These species were investigated on morphological variations and geographical distribution in Korea. The valuable taxonomic characters between similar species of this section were discussed with special reference to thickness of leaves, types of holdfasts, shape of leaves and vesicle, and length of rhizoids.

Morphological Differences of the Shells of Parafossarulus manchouricus ( Prosobranchia : Birthyniidae ) in Korea (한국산 쇠우렁 ( Parafossarulus manchouricus ) 패각의 형태학적 비교)

  • 김재진;최임순
    • The Korean Journal of Malacology
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    • v.3 no.1
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    • pp.35-43
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    • 1987
  • Morphological variations of six Korean and one Japanese populations of Parafossarulus manchouricus were observed. Mean length of shell was 9.36mm(n=376), and mean width was 8.0mm. Average aperture length and width were 4.72 and 3.78mm, respectively. Number of whorl ranged from 3.5 to 5.25(at most 4.5)in all popuiations . Yangsoori population had no spiral line or spiral keel, but ther populations had spiral lines. Number of spiral line on their penultimate shorls ranged 4 to 14.The lips of aperture were generally thickened, except in some Chongpyong, Haman and Fukuoka populations. The most of shell was eroded in only apex part and/ or in othker sculpture, especially Yangsoori population was heavily eroded.

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Morphological variation of Scenedesmus quadricauda (Turpin) de Br bisson and Scenedesmus armatus (Chodat) G.M. Smith in culture (내실배양에 따른 Scenedesmus quadricauda(Turpin) de Br bisson과 Scenedesmus armatus(Chodat) G.M. Smith의 형태변이)

  • 안선숙
    • Journal of Plant Biology
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    • v.28 no.4
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    • pp.305-315
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    • 1985
  • Morphological variations within the species of Scenedesmus in Korea, S. armatus and 2 strains of S. quadricauda were investigated. Taxonomic characters such as length of long spine, ridge, unicell-colony transformation, and colony types were compared. The length of long spine was constant, whereas the distribution of the spine varied with the age of culture. Ridge and short spine in S. armatus occurred constantly, whereas those in S. quadricauda varied with the composition of the media and age of culture. Strains CY-1 and CY-2 showed 6 different colony types in the stationary culture, whereas S. armatus formed only two types, armatus and armatus-longus types. All strains showed unicell-colony transformation. The cell became minimum when the daughter cell was released, and reached maximum at division.

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