| Sebastes schlegelii has become one of the important economic fish in north china because of its characteristic, such as fast growth, delicious, nutritious and resistance, etc. Overfishing and coastal ecological environment changes diminished the wild resources, therefore S. schlegelii is essential for the development and protection of germplasm resources, molecular marker assisted breeding is an effective tool for this work provides a convenient. This study first used simplified genome sequencing technology developed 49 polymorphic microsatellite markers, using microsatellite marker on wild population and the breeding population genetic diversity analysis, and analyzes the correlation between microsatellite markers and growth traits. 1. The isolation and characterization of 49 microsatellite lociTo simplify the genome sequencing of S. schlegelii, designed 384 pairs microsatellite primers, and 361 pairs of primers steady expansion, accounting for 94%. 49 pairs of primers showed polymorphism in the Changdao population of 30 individuals, and detected 204 alleles in total, each microsatellite loci alleles number(Na) is 2-25. Average number of alleles is 7.8478. The loci HJ6-30, HJ6-32, HJ6-57, HJ7-46, HJ9-6, HJ10-2, HJ10-6 are the minimum number of alleles, which just have 2 alleles. Locus HJ7-60 is the maximum number of alleles is 21 alleles. Effective number of alleles(Ne) is 1.1421 to 1.1421, with a mean of 4.5307. Observed heterozygosity(Ho) of 0.0417 to 0.0417, the mean is 0.5993; Expected heterozygosity(He) range of 0.0966 to 0.0966, with a mean of 0.6855. Polymorphism information content(PIC) between 0.0905 to 0.9088, with a mean of 0.5971, the number of highly polymorphic loci is 35, account for 71.42%, the moderately polymorphic and low polymorphic locus are both 7, each account for 14.29%. There are 15 loci are significantly deviate from the Hardy-Weinberg, 30.6% of the total. This research developed 49 microsatellite markers provides more markers for the construction of genetic map, molecular marker assisted breeding and so on. 2. Correlation analysis of microsatellite markers with body length, weight and height26 polymorphic microsatellite markers were selected to estimate a wild population of Sebastes schlegelii, which turns out that the numbers of alleles were 260 and alleles in each loci ranged from 3 to 21. The observed and expected heterozygosity values ranged from 0.0417-0.9999 and 0.0.1581-0.9456. The values of polymorphic information content ranged from 0.1509-0.9320. 22 microsatellite loci with high polymorphism were used to analyze the correlation with body length, weight and heightby single marker-based analysis. The results showed that loci HJ2-32 was significantly correlated with the 3 growth traits, allele D and C, respectively,has a positive and negative effect on growth traits. HJ7-2 has notable correlation with body weight; allele F and B of HJ7-22 played positive and negative roles in length traits respectively. The results of path analysis shows that the Pearson correlation coefficient between body height and body weight was greater than the body length and body weight, namely the direct effect of body height on body weight is greater than body length on body weight, which can be guide for breeding program. These aforementioned markers would benefit the further study on molecular marker-assisted breeding of Sebastes schlegelii. 3. Genetic diversity of the wild and cultured populationsSelected 24 polymorphism microsatellite markers for amplification ibetween a wild population and farming population, analyze the genetic diversity of the two populations. Comparison between Rongcheng wild population and Yantai cultured population with these markers shows: the mean allele number and the effective allele number were 8.5000, 6.9583, and 4.5484, 3.6365, respectively; the values of average expected heterozygosity were 0.6421 and 0.5840; the mean PIC were 0.6088 and 0.5490; the mean value of Shannon-Weiner index were 1.4605 and 1.2834; however, the difference is not statistically significant. High-genetic diversity was maintained in both wild and hatchery populations, but polymorphism of cultured population was lower than the wild, indicating a large number of broodstocks avoided the decreasing of genetic diversity in artificial breeding, but directional breeding affected the genetic diversity of breeding populations. 4. Gender-related microsatellite analysis of Sebastes schlegelii.Selected 28 microsatellite markers for screening gender correlation markers in two different gender of the Sebastes schlegelii populations. Anatomy to identify male and female gender, individual number are both 30. The results showed that the genetic diversity of male and female groups did not reach significant difference levels(P>0.05). 27 markers, except locus HJ10-35, specific alleles present in male and female individuals, but specific allele only appeared in some individuals. The result of pair sample T test showed that the allele frequency difference were not significant. And did not get microsatellite markers associated with gender accurately.These results indicated that these polymorphic microsatellite markers would be useful for the studies of population structure analysis, genetic linkage mapping, QTL analysis and other relevant research in S. schlegelii. The results of the genetic diversity analysis between wild and cultured populations provide the data base for artificial releasing and germplasm resources protection. The microsatellite markers correlated with growth traits can be used in molecular marker assisted breeding. Gender related research results for the Sebastes schlegelii sex identification of early accumulate basic data. |
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