The Development Of Microsatellite Markers And Application In Grouper

Grouper is an important economic fish in coastal marine aquaculture in our country.The selective breeding is one of the important means to maintain a healthy industry and sustainable development in aquaculture.The molecular markers have been applied in germplasm identification,pedigree selection and evaluation.In this study,we developed a multiplex microsatellite fluorescence PCR method for parentage identification in Epinephelus coioides.We also distinguished Half-sib Families in E.akaara with screened molecular markers.Moreover,we developed SSR markers based on the transcriptomicdata ofE.akaara.The majorresults were summarized as below:1.From the published microsatellite markers resources ofE.coioides,weselected 8 markers showing strong polymorphism,high heterozygosity and similar annealing temperature.By optimization of PCR conditions,wesetupa multiplex microsatellite fluorescence PCR system.This system had been tested with a full-sib family.The result proved that this system could be applied in parentage identification in E.coioides.2.We screened the published microsatellite markers of E.akaara and selected 1marker showing strong polymorphismin test samples.We applied the markerto distinguish the family origin of the individuals from the Half-sib Families of E.akaara.We finally identified 142 offsprings for one full-sib family.The full-sib family will be used in the construction of genetic linkage map constructionforE.akaara.3.From the transcriptomicdata of E.akaara,we randomly selected 119 microsatellite sequences for marker development.Aftergenotyping in one group population,we identified polymorphism 18 loci.The number of alleles per locus ranged from 3 to 15 and their allele sizes varied between 103 bpto 200 bp.The observed heterozygosity and expected heterozygosity were 0.333-0.967 and 0.483-0.877 respectively in the test population.The average values were 0.774 and 0.696 respectively.The PIC values ranged from 0.402 to 0.849 with an average value of 0.632.Conclusions: In this study,weestablish a multiplex microsatellite fluorescence PCR systemfor the grouper.This PCR system can be applied in family identification,genetic breeding,germplasm identification and evaluation in E.coioides.In addition,we developed18 polymorphism microsatellitemarkers in E.akaara,which can be used in germplasmevaluation and genetic breeding program of E.akaara.