• 한국육종학회지
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• 제40권3호
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• pp.263-268
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• 2008

잣나무 채종원의 유전간벌을 위하여 재적생장에 대한 개량 효과와 유효클론수를 이용한 유전다양성을 평가하였다. 유전 간벌은 클론의 일반조합능력으로 나타나는 육종가(breeding value), 암꽃과 수꽃 개화량을 이용한 종자생산 기여도, 클론별 ramet수 등를 이용한 클론별 변이를 기초로 하였다. 차대 검정 결과에 의하여 산출된 재적생장에 대한 클론별 일반조합능력(genetic value) 및 1991년부터 2003년까지 조사된 개화량 성적을 이용하여 잣나무 채종원(1981년 조성) 179클론에 대하여 간벌 강도에 따른 유전다양성 및 개량효과를 분석하였다. 이때 채종원 외부로부터의 화분오염율은 30%(gene migration = 15%)로 설정하였다. 그 결과 재적생장에 대한 개량효과는 간벌율이 10%에서 60%까지 높아짐에 따라서 점차 증가하였다. 하지만 이보다 더 높은 간벌 강도에서 현저한 개량효과 증가는 나타나지 않았다. 유효클론수는 간벌강도 10%에서 60% 사이에서는 40클론으로 나타났으며, 70% 간벌율 이상에서는 증가하거나 감소하는 변동을 나타냈다. 따라서 본 잣나무 채종원에 대해서는 50%에서 60% 수준의 간벌 강도가 적당한 것으로 판단된다.

• Journal of Plant Biology
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• 제38권2호
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• pp.173-180
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• 1995

We investigated levels and distribution of genetic variation in Korean populations of Calystegia soldanella and C. japonica, clonally reproducing herbaceous perennials. Calystegia soldanella is one ofecologically important beach plants growing only on sand and beach dunes in Europe, East Asia, the Pacific Islands, and the west coast of North America. In contrast, C. japonica usually grows on small mounds of paddy fields, roadsides, and waste places with patchy distribution. Starch gel electrophoresis was conducted on leaves collected from 13 populations of C. soldanella and eight populations of C. japonica. The levels of genetic variation of the two species are very comparable; means of expected heterozygosity (Hep) were 0.100 and 0.099 for C. soldanella and C. japonica, respectively. These values were also very similar to those for species with similar life-history and ecological traits. However, the proportion of total genetic diversity partitioned among populations (GST) of C. soldanella (0.146) was considerably lower than that of C. japonica (0.383). In addition, means of Nei's genetic identity (Ⅰ) for C. soldanella and C. japonica were 0.985 and 0.900, respectively, which supports a restricted gene flow resulting from obligate clonal reproduction of C. japonica. Significant differences in allele frequency were detected among populations at eight and nine of nine polymorphic loci for C. soldanella and C. japonica (P<0.01), respecitvely. Considering the ecological importance of C. soldanella, the isolated beach populations coupled with present destruction of natural habitats of the species may result in erosion of genetic diversity in the near future. In this respect, conservation efforts should be focused on those populations that currently maintain the most genetic diversity such as those populations in the eastern and southeastern Korean Peninsula and Hamduck Beach, Cheju Island.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2003년도 춘계 학술대회지
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• pp.36-36
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• 2003

• ALGAE
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• 제38권2호
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• pp.127-139
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• 2023

Cryptic stages of diverse macroalgae present in natural substrata, "the bank of microscopic forms", were isolated into clonal cultures and identified based on both morphological characteristics and DNA barcoding. Approximately 120 clonal isolates from 308 natural substratum samples were collected from the entire coastline of Kuwait. Amongst these isolates, 77 (64%) were identified through DNA barcoding using the nuclear ribosomal small subunit, RuBisCO spacer (ITS2, tufa, rbcL, psaA, and psbA) and sequencing. Twenty-six isolates (34%) were identified in the division Chlorophyta, 18 (23%) as Phaeophyceae, and 33 (43%) as Rhodophyta. For all DNA sequences in this study, species-level cut off applied was ≥98% homology which depend entirely on the markers used. Three putative new records of Chlorophyta new for the Arabian Gulf were made: Cladophora laetevirens (Dillwyn) Kützing, Ulva torta (Mertens) Trevisan and Ulvella leptochaete (Huber) R. Nielsen, C. J. O'Kelly & B. Wysor in Nielsen, while Cladophora gracilis Kützing and Ulva ohnoi M. Hiraoka & S. Shimada are new records for Kuwait. For Phaeophyceae, Ectocarpus subulatus Kützing and Elachista stellaris Areschoug were new records for the Gulf and Kuwait. In the Rhodophyta, Acrochaetium secundatum (Lyngbye) Nägeli in Nägeli & Cramer, Ceramium affine Setchell & N. L. Gardner, Gelidium pusillum var. pakistanicum Afaq-Husain & Shameel and Dasya caraibica Børgesen are new records for the Gulf and Kuwait, while the red alga Stylonema alsidii (Zanardini) K. Drew is a new record for Kuwait. Several isolates identified corresponded to genera not previously reported in Kuwait and / or the Arabian Gulf, such as Porphyrostromium Trevisan, a new genus from the Bangiales, and two unidentified species for the Planophilaceae Škaloud & Leliaert. The isolates cultivated from substrata enhance understanding of the marine macroalgal diversity in the region and confirmed that the Germling Emergence Method is suitable for determining the actual diversity of a given study area through isolation from cryptic life-history phases.

• 한국산림과학회지
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• 제96권5호
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• pp.528-532
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• 2007

Clonal differences in fertility (expressed as the number of female and male strobili) were determined for five consecutive years (2002-2006) in a clonal seed orchard of Chamaecyparis obtusa. Fertility varied among clones and among years with producing five-year averages of 378.8 and 871.2 for female and male strobili per ramet, respectively. Correlation between female and male strobilus production was positive over the five years and statistically significant. Based on the observed fertility variation, the effective population sizes (estimated by status numbers, $N_e$) were calculated and varied from 24.3 to 47.9 (48.6% to 95.8% of census number, N) among the five studied years. On average (pooled), the relative effective population size was 82% of the N. Variation in female fertility was higher than that in male fertility, and this variation was reflected on female and male parents' status numbers. Pooled $N_e$ estimated from the five years was higher than that from poor seed production years. From our results, it was concluded that genetic diversity collected from good flowering years would be higher than that from poor flowering years.

• 아시안잔디학회지
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• 제7권2_3호
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• pp.113-120
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• 1993

Dictyostelid cellular slime molds were quantitatibly isolated from Korean lawngrass turf in Seoul National University, Korea, by the 'Clonal Isolation Technique(Cavender and Raper, 1965a)'. Total six species were found. These are Dictyostelium sphaerocephalum. D. purpuream. D. flavidam, D. crassica ale, Polysphondilium pallidum. P. violaceum. D. sphaerocephalum was the dominant species and P. violaceum, D. flaviidum, D. crassicaule were rare. Compared with other region, species diversity and species richness of Korean lawngrass turf appeared to he low. The dominant species, however, is not very common in other plant communities, so it cnay he characteristic of Korean lawngrass turf.

• Journal of Ecology and Environment
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• 제35권1호
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• pp.27-34
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• 2012

Typha angustifolia has ecological characteristics of clonal growth similar to Phragmites australis. The plant spreads byclonal growth and seed dispersal. In this study, for the three stands which have different settlement age at the Baksilji wetland in Korea, genetic diversity was estimated by random amplification of polymorphic DNA analysis to evaluate the change in genetic diversity of T. angustifolia during stand development in the same population. Stand (ST) 1 was the oldest and ST 4 was the youngest. ST 5 was in a small ditch out of the Baksilji. Although the ST 1, ST 2, and ST 3 did not differ significantly in vegetational or physical environment, the genetic diversity estimated according to Nei's gene diversity (h) and the Shannon index (i) increased in the order of ST 1 < ST 2 < ST 3 contrary to formative age. The genetic diversity of ST 4 was much higher than that of the other three stands. ST 4 has similar abiotic environmental conditions with slight T. angustifolia dominance, and seems to be in the early establishment stage. ST 5 differed from the other stands in vegetational and soil environments, which can result in stressful cattail conditions. Even though the ST 5 stand was not younger than the ST 4 stand, ST 5 showed the highest genetic diversity. Our results indicate that after early settlement of the T. angustifolia population, genetic diversity within the species decreased over time and that the decreasing pattern of genetic diversity within T. angustifolia stands is not likely to occur under stressful conditions.

• 한국치위생학회지
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• 제13권5호
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• pp.889-900
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• 2013

Objectives : Molecular biology techniques were employed to assess diversity of bacterial in children's dental caries. Methods : DNA of germs was extracted and the diversity of the 16S rRNA clones was analyzed by amplified rDNA restriction analysis and sequencing. The experimental samples were pit and fissure caries (PC), deep dentinal caries (DC), smooth surface caries (SC), and supragingival plaque (PQ) from 50 children of age less than 12 years old. The control group was healthy teeth supragingival plaque (HT). Thirty clones from each 16S rRNA clone library of 5 samples were randomly selected, thus a total of 150 clones were analyzed. Results : Amplified rDNA restriction analysis uncovered 18, 20, 11, 17, and 22 phylotypes from healthy teeth, pit and fissure caries, deep dentinal caries, smooth surface caries, and supragingival plaque, respectively. Sequencing analysis found the dominance of Actinomycs naeslundii and Fusobacterium nucleatum in the healthy teeth; Leptotrichia sp. in the pit and fissure caries; Actinomyces sp., Streptococcus mutans, and Rahnella aquatilis in the deep dentinal caries; Streptococcus mutans and Actinomyces sp. in the smooth surface caries; Enterobacter hormaechei and Streptococcus sanguinis in the supragingival plaque. Conclusions : Clonal analysis identified 6 phyla, 20 genera, and 51 species.

• BMB Reports
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• 제52권9호
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• pp.540-547
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• 2019

Immune repertoire is a collection of enormously diverse adaptive immune cells within an individual. As the repertoire shapes and represents immunological conditions, identification of clones and characterization of diversity are critical for understanding how to protect ourselves against various illness such as infectious diseases and cancers. Over the past several years, fast growing technologies for high throughput sequencing have facilitated rapid advancement of repertoire research, enabling us to observe the diversity of repertoire at an unprecedented level. Here, we focus on B cell receptor (BCR) repertoire and review approaches to B cell isolation and sequencing library construction. These experiments should be carefully designed according to BCR regions to be interrogated, such as heavy chain full length, complementarity determining regions, and isotypes. We also highlight preprocessing steps to remove sequencing and PCR errors with unique molecular index and bioinformatics techniques. Due to the nature of massive sequence variation in BCR, caution is warranted when interpreting repertoire diversity from error-prone sequencing data. Furthermore, we provide a summary of statistical frameworks and bioinformatics tools for clonal evolution and diversity. Finally, we discuss limitations of current BCR-seq technologies and future perspectives on advances in repertoire sequencing.

• Journal of Forest and Environmental Science
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• 제38권1호
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• pp.12-20
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• 2022

Pongamia (Pongamia pinnata L.) as a source of non-edible oil, is potential tree species for biodiesel production. For several reasons, both technical and economical, the potential of P. pinnata is far from being realized. The exploitation of genetic diversity for crop improvement has been the major driving force for the exploration and ex situ/in situ conservation of plant genetic resources. However, P. pinnata improvement for high oil and seed production is not achieved because of unsystematic way of tree improvement. Performance of P. pinnata planted by Karnataka Forest Department was assessed based on yield potential by collecting 157 clones out of 264 clones established by Karnataka Forest Department research wing under different research circles/ranges. It was evident that the all the seed and pod traits were significantly different. Further, selection of superior germplasm based on oil and pod/seed parameters was achieved by application of Mahalanobis statistics and Tocher's technique. On the basis of D² values for all possible 253 pairs of populations the 157 genotypes were grouped into 28 clusters. The clustering pattern showed that geographical diversity is not necessarily related to genetic diversity. Cluster means indicated a wide range of variation for all the pod and seed traits. The best cluster having total oil content of more than 34.9% with 100 seed weight of above 125 g viz. Cluster I, II, III, IX, XV, XIX, XXI, XXIII, XXVI and XXVII were selected for clonal propagation.