• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.473-480
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• 1983

To obtain basic information on the Korean local com lines a total of 57 lines were selected from 1,000 Korean local collection at Chungnam National University, and classified by principal component analysis, and genetic nature was investigated. There were a great variation in mean values of plant characters of the lines. The mean values of plant characters except for density of kernels varied with types of crossing. All characters except for tasselling dates were reduced in magnitude when selfed, while those characters were increased when topcrossed. The inbreeding depression varied with plant characters and lines. The characters such as yield, kernel weight per ear, ear weight and plant height showed great degree of inbreeding depression. Group I showed high inbreeding depression in such characters as 100 kernel weight, leaf number, plant height and days to tasselling, while group II showed high inbreeding depression in other plant characters. Heterosis of plant characters varied also with lines. The ear weight, kernel weight per ear, yield, 100 kernel weight, and plant height were some of the plant characters showing high heterosis. Group II showed high values of heterosis in such characters as ear length, ear diameter, ear weight, kernel weight per ear, 100 kernel weight and leaf length, while group I was high in heterosis in other plant characters. The degree of homozygosity was highest in ear weight (79.1%) and lowest in ear number per plant (-2.1%). Group II showed higher degree of homozygosity than group I. Correlation coefficients between characters of sibbed and topcrossed lines were positive for all characters. Highly significant correlation coefficients between sibbed and topcrossed lines were obtained especially for characters such as ear number per plant, plant height, leaf length and yield per plot.

• Journal of Sericultural and Entomological Science
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• v.37 no.1
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• pp.10-15
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• 1995

Genetic characterization of Sri Lankan silkworm bivoltine population has not been at-tempted so far, since its sporadic introduction of bivoltine strains into the island, starting from the 1950's. Genetic structure of Sri Lankan population of mulberry silkworm Bombyx mori was investigated through estimation of general (GCA) and specific combining ability(SCA) and heritability(${h^2}_B$), on the economic quantitative characters from leading 8 inbreds and their 28 F1's in a half diallel cross, in an attempt to utilize the estimates in determination of future breeding methods and to predict the breeding value over the phenotypic value. It was found that the breeding population of the bivoltine silkworm in Sri Lanka has still maintained considerable amounts of additive gene action as well as nonadditive. For some time in the future, both breeding strategies of "selection without inbreeding" and also "inbreeding followed by crossing" should therefore be effective in genetic improvement of economic characters investigated. In addition, superior combiners in general and in specific F1′s were identified for each of 6 economic characters, to be immediately utilized in selection and also in cross breeding programs in Sri Lanka.

• Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.151-155
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• 2012

We used nine microsatellite DNA markers to estimate genetic variation among wild and cultured populations of the sea squirt Halocynthia roretzi. The loci were polymorphic, with 6-32 alleles, and allelic richness ranged from 6.0 to 26.1 in each population. The wild and the cultured populations had similar mean heterozygosities ($H_O$ and $H_E$), allele numbers, and allelic richness. One cultured population with softness syndrome had a lower mean in the observed heterozygosity ($H_O$ = 0.57) and higher mean inbreeding coefficient ($F_{IS}$ = 0.261) than any other populations. This suggests that the loss of genetic variation in the diseased population might be due to increased inbreeding. A neighbor-joining tree and pairwise population estimates of $F_{ST}$ showed moderate genetic differentiation between the wild and the cultured populations. Additionally, the softness syndrome population was genetically divergent from wild populations, but it was genetically close to the cultured populations.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.428-434
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• 1997

The effect of genetic diversity in sub-populations on breeding efficiency was examined with prospect of potential crossbreeding. Simulation study of selection was performed for 20 generations with 20 replications each, comparing average breeding values and inbreeding coefficients between the two breeding systemes; single population scheme and two population scheme. The different genetic levels were assumed to be caused by different gene frequencies. Phenotypes of two traits generated polygenic effect with additive 36 loci and residuals distributed normally were selected by selection index procedure. High genetic gain with less inbreeding was clearly recognized in the single population scheme, independently of difference in genetic level, economic weight and genetic correlation. Genetic correlation after selection in the single population scheme was lower than the two population scheme. When crossbreeding between the sub-population was taken into account, superiority of the two population scheme was suggested under those restrictions; difference in genetic level is moderate, selection criterion for the two traits is not far from even economic weight, and genetic correlation is positive with low to moderate value. The use of complementarity increased the possibility of the two population scheme.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.633-637
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• 2007

Genetic variation in Nilagiri sheep, the only apparel wool breed in South India was studied using 25 FAO recommended ovine-specific microsatellite markers. The number of observed alleles ranged from 3 to 8 with a mean of 5 across all loci. The size of alleles ranged from 72 to 228 bp. The frequency of alleles ranged from 0.0104 to 0.5781. In total, 125 alleles were observed at the 25 loci studied. The effective number of alleles ranged from 2.18 to 6.49. The mean number of effective alleles was 3.84 across all loci. All the 25 loci were found to be highly polymorphic. The PIC values ranged from 0.4587 to 0.8277 with a mean of 0.6485. Of 25 microsatellites studied, 17 were in Hardy-Weinberg Equilibrium proportions. The observed heterozygosity ranged from 0.4222 to 1.000 with a mean value of 0.7610 whereas the expected heterozygosity ranged from 0.5415 to 0.8459 with a mean value of 0.7213. Except six loci, the other loci revealed negative within-population inbreeding estimates (FIS) indicating excess of heterozygotes in the population of Nilagiri sheep.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.4
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• pp.357-364
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• 1995

A biochemical genetic study on blood enzyme/protein systems in some breeds/crosses of sheep in Malaysia was carried out using horizontal starch gel electrophoresis. Blood samples were collected from 435 sheep, representing 8 breeds/crosses. These included 5 wool sheep breeds (Thai Longtail, wiltshire, Suffolk, Dorsimal and cMBLx), 1 hair sheep breed (Barbados Blackbelly) and 2 hybrids between wool sheep and hair sheep (Cameroon ${\times}$ Thai Longtail and Bali Bali ${\times}$ Malin). Twenty loci systems were examined. Of these, ten ($HB{\beta}$, ALB, TF, XP, CAT, DIA1, EsA, GPI, ME and NP) exhibited genetic variation whereas the other ten (AAT, CA, DIA2, ${\alpha}GLO$, ${\alpha}GLU$, LDH, MDH, PEP[leu-gly-gly], 6PGD and SOD) were monomorphic. The allelic frequencies which were obtained in 10 polymorphic markers are assessed and compared with the results obtained by previous workers. The estimations of inbreeding coefficient, intrabreed variation and breed relationships have been critically discussed and are used to reveal some important recommendations.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.2
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• pp.121-126
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• 2002

Breeding programme was initiated during November, 1995 with the main objective to breed productive multivoltine breeds/ hybrids with suitable genetic constitution to suit the fluctuating tropical climate prevailed in India. Two multivoltine breeds viz., BL-24 and BL-27 selected were as breeding resource materials from the silkworm germplasm maintained at Central Sericul-tural Research and Training Institute, Mysore. By adopting hybridization, backcrossing inbreeding and selection, a new multivoltine breed namely BL-67. This breed spins light greenish yellow cocoons and cocoon shape is oval with medium to coarse grains. The evolved breed was crossed with five tropical bivoltine breeds viz., NB4D2, CSR2, CSR5, CSR18 and CSR101 to study the combining ability, and identified a superior hybrid, BL67 ${\times}$ CSR101, named as CAUVERY, The hybrid is characterized by high pupation rate (>95%), high shell weight (> 35 cg), high cocoon shell ratio (> 20%), longer filament length (> 900 m) and high neatness (93) with a renditta of 6.5 producing 2A-3A grade silk. The hybrid is selected for Race Autho-rization test of Central Silk Board.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1552-1556
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• 2010

The aim of this study was to evaluate, through the use of microsatellite markers, the current genetic diversity and the relationships of 375 individuals from 8 local sheep breeds reared in typical breeding farms in the northwest of China, and moreover, to offer a contribution towards genetic conservation decisions for the studied breeds. The expected heterozygosities and allelic richness for the 8 breeds varied from 0.474 to 0.623 and from 3.8 to 5.4, respectively. All the populations showed a significant deficit in heterozygosity and a relatively low level of genetic diversity. Furthermore, the high positive FIS value (ranging from 0.255 to 0.556) indicated inbreeding to be one of the main causes for high genetic homogeneity and lack of heterozygosity in all breeds. The clustering analysis performed with the DISPAN package showed that Aletai, Kazak, Bashibai and Bayinbuluke were grouped together, and Hetian, Qira black and Duolang were grouped together, which indicated that the relationship among breeds displayed some degree of consistency with their geographical distribution, production and origin. These findings indicate that improved conservation measures must be undertaken to avoid further losses of genetic diversity and minimize inbreeding represented by these breeds.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.2
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• pp.120-128
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• 2021

The objective of this study was to analyze the genotype of black-spotted pond frog (Pelophylax nigromaculatus) using seven microsatellite loci to quantify its genetic diversity and population structure throughout the spatial scale of basins of Han, Geum, Yeongsan, and Nakdong Rivers in South Korea. Genetic diversities in these four areas were compared using diversity index and inbreeding coefficient obtained from the number and frequency of alleles as well as heterozygosity. Additionally, the population structure was confirmed with population differentiation, Nei's genetic distance, multivariate analysis, and Bayesian clustering analysis. Interestingly, a negative genetic diversity pattern was observed in the Han River basin, indicating possible recent habitat disturbances or population declines. In contrast, a positive genetic diversity pattern was found for the population in the Nakdong River basin that had remained the most stable. Results of population structure suggested that populations of black-spotted pond frogs distributed in these four river basins were genetically independent. In particular, the population of the Nakdong River basin had the greatest genetic distance, indicating that it might have originated from an independent population. These results support the use of genetics in addition to designations strictly based on geographic stream areas to define the spatial scale of populations for management and conservation practices.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.107-116
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• 2016

The study was aimed to analyze pedigree structure and inbreeding coefficients for performance tested Holstein cows in Korea. A total of 400,029 Holstein cows data which born between 2002 and 2012 were obtained from Dairy Cattle Improvement Center of National Agricultural Cooperative Federation(NACF). Their related pedigrees, as obtained from Korean Animal Improvement Association(KAIA), consisted of 509,740 animals. Pedigree depth of the cows were traced back to 3 generations earlier. The percentage of cows with fully identified ancestors in various provinces of Korea were 55.18%(Gyeonggi-do), 23.49%(Gangwon-do), 47.83%(Chungcheongnam-do), 53.62%(Chungcheongbuk-do), 56.38%(Gyeongsangbuk-do), 51.35% (Gyeongsangnam-do), 26.58%(Jeollanam-do), 49.41%(Jeollabuk-do), and 56.90%(Jeju-do), whereas, it was about 63.20% as a whole in Korea. The average inbreeding coefficients showed increment across the consecutive years of birth such as, 0.43(2002), 0.44(2003), 0.58(2004), 0.64(2005), 0.78(2006), 0.93(2007), 1.08(2008), 1.23(2009), 1.46(2010), 1.77(2011), and 2.03 (2012). However, this coefficient was 0.93 in overall Korean population. An average generation interval for sire to daughter genetic path was 8.15 years; which was about 4.20 years considering dam to daughter genetic path. The estimated effective population sizes (Ne) were 56.5, 51.3, and 32.2 animals born in 2004, 2009, and 2012, respectively. These results indicated that an increased rate of inbreeding has led to a significant reduction in the Ne over the decade.