Genetic Parameters Estimation And Correlation Analysis Between Growth-related Traits And Microsatellite Markers In Large Yellow Croaker Larimichthys Crocea

We estimated the reproductive success of adult brood fish for large yellow croaker(Larimichthys crocea). We created two independent full-factorial cross groups (1and2) bycrossing4males×4females and4males×3females, respectively. We also collected a tissuesample from each individual of the parents and599offsprings (281from group1and318fromgroup2) at20-month-old age. The parents and offsprings were genotyped using six polymorphicmicrosatellites. Of the599offsprings,99.2%were assigned to a single pair of parents. In bothgroups, some parent pairs produced a large number of offsprings while some pairs did notproduce any offspring. The genetic diversity and the putative effective genetic size of thepopulation (Ne) were lower in the offsprings than in the parents in both groups. The loss ofputative Ne was68.6%and57.3%for group1and group2，respectively.We measured the body weight (BW), body length (BL), and body height (BH) of281individuals from group1and318individuals from group2at20months post hatch.With thepedigree information which was given in parentage analysis, we estimated the heritability ofgrowth-related traits including body weight, body length and body height. The heritabilityestimates at20-month age were0.13±0.10for BW,0.19±0.13for BL, and0.09±0.06for BH. Thegenetic and phenotype correlation between BW, BL and BH was close to1. It means that othertwo phenotypic characters would obtain genetic improvement indirectly if one of the three wastaken select breeding trait directly.In this study,32microsatellite markers from the SSR linkage map of large yellow croaker wereselected to reveal the correlation between the markers and growth-related traits, and60individuals came from a single full-sibs family (the maximal30and the minimal30) of largeyellow croaker was investigated. The results were as follows: The locus of LYC0088and locusLYC0143had a extremely significant correlation in the body length, body height and bodyweight of the large yellow croaker (P<0.01), and the locus of LYC0200had a significantcorrelation in the body length (P<0.05). Use60individuals (30maximal individuanls and30minimal individuals) in group1to verify the LYC0088, LYC0143and LYC0200, and the resultsshowed that LYC0088and LYC0143had a significant correlation in the body length, body heightand body weight of the large yellow croaker(P<0.05). Select120individuals from a singlefull-sibs family of group2to verify LYC0088, LYC0143, and the results showed that LYC0088 and LYC0143had an extremely significant correlation in the body length, body height and bodyweight of the large yellow croaker.