• Title/Summary/Keyword: phenotypic selection

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Estimation of Heritabilities of Growth Traits, and Phenotypic and Genetic Correlations in Adult Masu Salmon (Oncorhynchus masou) (성어기 시마연어의 성장형질에 대한 유전율 및 표현형 상관과 유전 상관의 추정)

  • Choe, Mi-Kyung;Yeo, In-Kyu
    • Korean Journal of Ichthyology
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    • v.12 no.2
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    • pp.118-123
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    • 2000
  • Heritabilities of growth traits, and phenotypic and genetic correlations for rearing masu salmon Oncorhynchus masou in adult stage were described. Genetic parameters were estimated for total length, body weight, and head length of masu salmon at 19 and 23 months of age. The heritabilities of growth traits estimated for sire component at 19 months of age was 0.22 in each trait in 1995, and ranged from 0.19 to 0.36 at 23 months of age in 1996. Phenotypic and genetic correlations were high among growth traits(0.85~0.98, 0.67~1.26, respectively). Family selection or that combined with individual selection is proposed to improve growth of masu salmon.

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Comparison of Selection Efficiency between Marker-Assisted Selection and Phenotypic Selection for Development of Brown Planthopper Resistance Lines in Rice (벼멸구 저항성 계통선발을 위한 MAS의 선발효율 비교)

  • Kim, Suk-Man;Sohn, Jae-Keun
    • Korean Journal of Breeding Science
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    • v.40 no.1
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    • pp.48-53
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    • 2008
  • This study presents a case study designed to compare the selection efficiency between phenotypic selection (PS) and marker-assisted selection (MAS) in breeding of resistance lines to brown planthopper (BPH). The efficiency between PS and MAS were compared with four population such as the $F_2$, RILs ($F_6$), DH, and backcrosse ($BC_6F_5$) population, derived from a cross 'Samgang / Nagdong'. The resistance lines were selected using two markers, RM28493 and BpE18-3, related to BPH resistance were screened as resistance lines over 95% in PS. The costs required for BPH screening in the MAS system account for approximately 32% of the total costs of PS. The period needed to select the resistance plants was 30 days in PS and 7 days in MAS. Based on the results, we could establish the breeding system for selection of BPH resistance lines by MAS.

Phenotypic Characterization of Amaranth Resources for the Selection of Promising Materials

  • Hwang Bae Sohn;Su Jeong Kim;Jung Hwan Nam;Do Yeon Kim;Jong Nam Lee;Su Young Hong;Yul Ho Kim
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.211-211
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    • 2022
  • Amaranth is a nutritious and broadly adapted seed crop in high demand around the world. A preliminary approach for understanding the genetics of amaranth resources entails a morphologic characterization, which can provide the basis for breeding the first variety in Korea, leading to satisfying the needs of farmers and consumers. Therefore, this study aimed to evaluate the phenotypic characteristics of ten genetic amaranth accessions for the selection of outstanding accessions in terms of yield and grain quality. A randomized complete block design was used, with fifteen replications for each accession under field conditions. Five quantitative and three qualitative descriptors were evaluated with descriptive analysis. The results showed that the accessions with plant heights smaller than the average (>112.7 cm) presented lower yields and smaller seed sizes, thus decreasing the grain quality. The cluster analyses established groups of accessions with good yields (>30.1 g of seeds per plant) and stable morphological characteristics. Based on yield and morphological descriptors, the proposed selection index indicated four accessions as potential parents for amaranth breeding programs in Kora.

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Selection Responses for Milk, Fat and Protein Yields in Zimbabwean Holstein Cattle

  • Mandizha, S.;Makuza, S.M.;Mhlanga, F.N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.7
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    • pp.883-887
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    • 2000
  • One way of evaluating the effectiveness of a dairy breeding program is to measure response to selection. This may be direct or indirect. The objectives of this study were to estimate expected progress for direct selection on milk, fat and protein yields; to estimate the expected correlated responses on indirect selection for milk, fat and protein yields in Zimbabwean Holstein cattle and to establish the effect of selection intensity on responses. The Animal Model contained fixed effects of herd, year of calving, calving month, dry period, milking frequency and additive effects pertaining to cows, sires and dams. AIREML software package was used to analyse the data. The genetic and phenotypic parameters obtained in this study were used to compute direct and correlated responses to selection. Because of the higher heritabilities in first parity, genetic progress was found to be greater when selection was practised on first parity cows as compared to later lactations. It is therefore recommended that older cows in the herd be replaced with improved heifers so as to enhance genetic progress.

A whole genomic scan to detect selection signatures between Berkshire and Korean native pig breeds

  • Edea, Zewdu;Kim, Kwan-Suk
    • Journal of Animal Science and Technology
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    • v.56 no.7
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    • pp.23.1-23.7
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    • 2014
  • Background: Scanning of the genome for selection signatures between breeds may play important role in understanding the underlie causes for observable phenotypic variations. The discovery of high density single nucleotide polymorphisms (SNPs) provide a useful starting point to perform genome-wide scan in pig populations in order to identify loci/candidate genes underlie phenotypic variation in pig breeds and facilitate genetic improvement programs. However, prior to this study genomic region under selection in commercially selected Berkshire and Korean native pig breeds has never been detected using high density SNP markers. To this end, we have genotyped 45 animals using Porcine SNP60 chip to detect selection signatures in the genome of the two breeds by using the $F_{ST}$ approach. Results: In the comparison of Berkshire and KNP breeds using the FDIST approach, a total of 1108 outlier loci (3.48%) were significantly different from zero at 99% confidence level with 870 of the outlier SNPs displaying high level of genetic differentiation ($F_{ST}{\geq}0.490$). The identified candidate genes were involved in a wide array of biological processes and molecular functions. Results revealed that 19 candidate genes were enriched in phosphate metabolism (GO: 0006796; ADCK1, ACYP1, CAMK2D, CDK13, CDK13, ERN1, GALK2, INPP1; MAK, MAP2K5, MAP3K1, MAPK14, P14KB, PIK3C3, PRKC1, PTPRK, RNASEL, THBS1, BRAF, VRK1). We have identified a set of candidate genes under selection and have known to be involved in growth, size and pork quality (CART, AGL, CF7L2, MAP2K5, DLK1, GLI3, CA3 and MC3R), ear morphology and size (HMGA2 and SOX5) stress response (ATF2, MSRB3, TMTC3 and SCAF8) and immune response (HCST and RYR1). Conclusions: Some of the genes may be used to facilitate genetic improvement programs. Our results also provide insights for better understanding of the process and influence of breed development on the pattern of genetic variations.

Studies on the Selection Aduzki Bean Breeding. IV. Phenotypic and genotypic correlations in Adzuki bean cross

  • Kwon-Yawl Chang;Kyung-Soo Han;Jung-Choon Park
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.5 no.1
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    • pp.51-56
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    • 1969
  • Fourty lines of F4 progenies of an Adzuki bean cross, Jukdoo (Korean local variety) X Nesumimochi (Japanese variety) were used as the material, and these lines were grown in replicated trials in 1967. Phenotypic, genotypic and environmental covariances among all possible traits of eight character are calculated as shown in table 1. Phenotypic, genotypic and environmental correlations among all possible paris of eight characters were calculated as shown in table 2. In general, genotypic correlations were higher than the corresponding phenotypic corresponding phenotypic correlations. The genotypic correlations between seed yield (grain weight per plot) and oter agronomic characters indicated that seed yield was genetically associated with the character of pod number per plant, and grain number per plant, which is closely correlated with pod number pr plant, are affected more in Adzukl bean yield than the other agronomic characteracters.

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Genetic (Co)variance Components for Body Weight and Body Measurements in Makooei Sheep

  • Abbasi, Mokhtar-Ali;Ghafouri-Kesbi, Farhad
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.6
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    • pp.739-743
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    • 2011
  • The aim of this paper was to estimate genetic parameters for body weight and five body measurements for an experimental population of Iranian Makooei sheep maintained at the Makooei Sheep Breeding Station at Makoo, Iran. To do this, yearling live weight (YW), and five body measurements, i.e., body length (BL), heart girth (HG), height at withers (HW), height at back (HB) and scrotal circumference (SC), were analyzed in a multi-trait animal model using the DXMUX program of DFREML software package. Heritability estimates were $0.22{\pm}0.08$, $0.11{\pm}0.06$, $0.21{\pm}0.07$, $0.17{\pm}0.06$, $0.17{\pm}0.06$ and $0.32{\pm}0.10$ for YW, BL, HG, HW, HB and SC, respectively. These estimates indicate that selection in Makooei sheep would generate moderate genetic progress in body weight and body measurements. Scrotal circumference, as an indicator of reproductive potential, exhibited the highest heritability. This trait, therefore, could successfully be used to increase productivity of males and, indirectly, female fertility. Genetic correlations between traits studied were all positive and ranged from 0.15 (YW/HB) to 0.99 (HW/HB). Phenotypic correlations were also positive and ranged from moderate (0.32, HW/SC) to high (0.94, HW/HB). Positive genetic and phenotypic correlations indicate that improvement in body measurements both at the genetic and phenotypic levels is expected through selection on body weight and vice versa.

Agronomic Characters and Their Correlation Coefficient on Black Seeded Soybeans Collected in Chonnam Province

  • Kwon, Byung-Sun;Choi, Seong-kyu;Shin, Jeong-Sik;Shin, Dong-Youn;Kyu Hwan
    • Plant Resources
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    • v.5 no.2
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    • pp.118-123
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    • 2002
  • In order to obtain the genetic information on the quantitative characters of black seeded soybeans, which would be needed to improve selection efficiency for breeding high yielding genotype, 45 varieties of black seeded soybeans collected in Chonnam, Korea were grown and variations of several important characters were observed. Heritability of each observed character, phenotypic and genotypic correlations among the characters and contribution of each yield component on grain yield through path coefficient analysis were estimated. Both number of pods per plant and 100-seed weight showed not only high heritability but also highly significant phenotypic and genotypic correlation with seed yield, and hence it was desirable to select plants with more number of pods per plant and higher 100-seed weight than raise seed yield of black seeded soybeans collected in Chonnam. In addition, number of pods per and 100-seed weight were proved to be the most influential variables on the viability of seed yield by path coefficient analysis. Since these showed the high heritability of number of pods per plant, selection of plants with higher 100-seed weight would be more efficient for breeding high yielding genotype.

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Microscopic Image-based Cancer Cell Viability-related Phenotype Extraction (현미경 영상 기반 암세포 생존력 관련 표현형 추출)

  • Misun Kang
    • Journal of Biomedical Engineering Research
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    • v.44 no.3
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    • pp.176-181
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    • 2023
  • During cancer treatment, the patient's response to drugs appears differently at the cellular level. In this paper, an image-based cell phenotypic feature quantification and key feature selection method are presented to predict the response of patient-derived cancer cells to a specific drug. In order to analyze the viability characteristics of cancer cells, high-definition microscope images in which cell nuclei are fluorescently stained are used, and individual-level cell analysis is performed. To this end, first, image stitching is performed for analysis of the same environment in units of the well plates, and uneven brightness due to the effects of illumination is adjusted based on the histogram. In order to automatically segment only the cell nucleus region, which is the region of interest, from the improved image, a superpixel-based segmentation technique is applied using the fluorescence expression level and morphological information. After extracting 242 types of features from the image through the segmented cell region information, only the features related to cell viability are selected through the ReliefF algorithm. The proposed method can be applied to cell image-based phenotypic screening to determine a patient's response to a drug.

ESTIMATES OF PHENOTYPIC AND GENETIC PARAMETERS FOR WEANING AND YEARLING WEIGHTS IN BALI BEEF CATTLE

  • Djegho, Y.;Blair, H.T.;Garrick, D.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.4
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    • pp.623-628
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    • 1992
  • Records on weaning (3803) and yearling weight (2990) of beef cattle (Bibos banteng) from the Bali Cattle Improvement Project were examined. A mixed model analysis involving all main non-genetic effects (village, year of birth, season of birth, age of dam, sex of calf, all significant interactions and age at weighing as a covariate) as fixed effects and sire nested within village as a random effect was undertaken. Variance components were estimated by Henderson's Method III. Paternal half-sib components of variance and covariance were used to estimate heritabilities of weaning and yearling weights, as well as their genetic and phenotypic correlations. Heritability estimates ($\pm$ standard error) obtained by Henderson's Method III for weaning and yearling weights were $.11{\pm}.03$ and $.13{\pm}.04$, respectively while the phenotypic and genetic correlations were estimated as .32 and $.64{\pm}.10$, respectively. The parameters estimated in this study were at the lower end of the range of reported values from various breeds. It is concluded that further information should be gathered to assist in estimating genetic parameters for other economic traits of Bali beef cattle and to provide more accurate estimates for weaning and yearling weights. These parameters should then be used to formulate a selection program to enable the genetic improvement of Bali Beef cattle.