Family Establishment, Quantitative Genetic Analysis Of Growth And Sex Related Traits And QTL Mapping Of Paralichthys Olivaceus

Paralichthys olivaceus is one of the China, Japan and South Korea and other countries of the important economical marine fish culture, in fishery production has an important position.However, with the rapid development of flounder aquaculture, high density intensive farming has increased the mortality of Japanese flounder. The growth rate is also greatly reduced. Cause certain economic losses to the aquaculture of flounder. The development of flounder breeding and pedigree breeding work has important practical significance to further improve the yield and quality. This paper makes quantitative genetic analysis on growth traits of Japanese flounder at different growth stages. Combined with QTL positioning method to locate the flounder gender genes associated with growth achieved some results:1 This experiment by 2014 to establish the flounder family, were measured in 140, 170, 200, 380 days of age growth related traits（body weight, total length, body width）. The number of genetic analysis by MINQUE, REML and BLUP methods. The results showed that: The coefficient of variation of traits in different growth period for descriptive analysis 10.56%-38.62%. The variation coefficient of the maximum weight, total length and body width of the coefficient of variation is relatively small, the coefficient of variation of different traits decreased with the increase of age and. Additive variance ratio of the 3 traits was 0.13±0.014-0.29±0.064. Random variance component was 0.71±0.064-0.87±0.014. The narrow heritability was 0.13±0.014-0.29±0.064. The broad sense heritability was 0.15±0.014-0.54±0.064. The above genetic parameters reached extremely significant level（P<0.01）. Comprehensive genetic effects in different periods of the 3 traits showed that F0990, F1005, KS and F0719 in 4 groups of parents are extremely significant positive effect. F0751, F0768, F0780, F09121, F0927 and RS in 6 groups of parents is a significant negative effect（P < 0.01）. The rest of the parent was general effect. Phenotypic correlation coefficient was between 0.82 and 0.96. The genetic correlation between 0.72- 0.97 days of age, different phenotypic and genetic correlation coefficient is not changed, maintained at a stable level. By the method of BLUP data of 380 days of measurement estimation of breeding value, the parent fish breeding value of 14.63- 100.05 weight. The weight value of the highest breeding parent fish: F1005-8, F09119-11, F09125-4, F0915-57, F09104-12, F1264, F0908-38, F0927-20, F1005-53, F0990-6, F09125-7, F0751-14 and F1005-42. The average weight of family breeding value of 20.87- 35.6, the average weight of the breeding value of the highest family for F1416, F1428, F1442, F1418, F1427, F1408, F1402, F1412 and F1446. Through this research, foster the establishment of a fine family for flounder and new varieties were screened with excellent traits of parents and family. Provides an important theoretical basis for the development of Japanese flounder breeding plan.2 QTL mapping was carried out on the gender of flounderbecause male and female individual difference is obvious. Successfully constructed 22 linkage groups, the overall observation length of the integrated map was 994.34 c M, the average interval is 10.81 c M, the number of markers on the linkage group were 2-9. Coverage rate reached 82.09%. Pinpoint five range related to gender. The highest q GT-m8 value of LOD was 9.83, the coverage area is 44.4-46.1c M, can explain the phenotypic variation rate was 75.3%, the left marker is adjacent to the scaffold2₂20, the right marker is adjacent to the scaffold582₃195. The highest q GT-f15 value of LOD was 4.9, the coverage area of 44.7-46.1c M, explained the phenotypic variation of 80.91% adjacent markers on the left is the scaffold581₃651.The marker is scaffold526₄9786. QGT-f19 location out of the 2 ranges, the highest LOD value was 13.6, coverage areas were 0.1-5.8c M and 28.3-29.1c M. The rate of phenotypic variation was 69.12%, 78.57%. The first interval adjacent to the left side of the tag is scaffold307₃4397, the right side is scaffold1249₇7184. Second adjacent to the left side of the marker is scaffold247₂8440, the right side is scaffold599₅4404. The highest q GT-f23 value of LOD was 71.25, the coverage area of 1.1-6.1c M, explained the phenotypic variation of 88.96% adjacent markers left is scaffold1028₅334, right side marker scaffold1058₇3722. The results showed that the correlation between the 19 linkage groups and the sex related genes was the largest.Through the 19 chain group encryption to re construct the linkage map, there were 22 markers in the integrated map. The total length was 147.70 c M, the average distance was 6.71 c M, coverage rate was 84.04%. There were 18 markers in the female map. The total length was 96.5c M, the average distance was 5.36 c M, coverage rate was 80.97%. There were 16 markers linked to the male map. The total length was 91.67 c M, the average distance was 5.73 c M, coverage rate was 81.04%. Application integration map to locate the 3 QTL range, lengths were 8.4c M, 4.1c M, and 2.2c M. The female map was used to locate the length of 3 QTL, lengths were 3.6c M, 1.2c M, 1.2c M. Mapping the male pattern to 0 QTL ranges. The research results provide a reference interval for further exploration of sex related genes.