The Growth Performance Comparison And Genetic Diversity Analysis Of Different Body Color Red Tilapia

In this paper,the growth performance and genetic diversity of different body color red tilapia were studied to screen the growth related molecular markers,in order to establish an effective way improving culture performance and provide theoretical basis breeding excellent growth performance and uniform body color red tilapia.The results are as follows:1.The growth performances(body weight(BW),body length(BL),body height(BH)and body thickness(BT)of three body colors red tilapia(pink,red spots and black spots)were observed and analyzed for 12 months.The growth dynamic was basically same with rising trend for the three red tilapia groups.The highest absolute and specific growth rate were found during October and December;The growth rate of "Pink" red tilapia was significantly higher than that of two other groups from the begining(P<0.01).The variation coefficient of fish body weight and condition factor(CF)were 22%to 35%and 3.6 to 4.7 respectively in different months.The pink red tilapia had the highest CF for every month.The results provided a theoretical basis for further breeding of red tilapia.2.Genetic diversity of the three fish grous were analyed by fourteen microsatellite loci.(1)59 alleles were amplified in 14 loci of three body colors red tilapia and three to five alleles was amplified in each locus.The mean numbers of alleles of three body colors red tilapia were 4.1428,4.1428 and 3.7142 respectively.The mean numbers of effective alleles were 3.3550,3.5288 and 2.7893 respectively.The average expected heterozygosity were 0.6708,0.7150 and 0.6945 respectively.The average observed heterozygosity were 0.7094,0.7186 and 0.6324 respectively.The numbers of effective alleles,expected heterozygosity and observed heterozygosity of red spots red tilapia were highest,following the pink fish grouy.There is no significant difference beween the red and pink red tilapia(P>0.05).(2)Fst values between the pink and red spots,pink and black spots,red spots and black spots were 0.00335,0.06733 and 0.12298 respectively,which showed that the genetic differentiation between the pink and red spots red tilapia populations was weak.Combining the analysis results of AMOVA,only 3.07%of total genetic variations derived from populations.The results showed that the genetic variation and correlation of body color were significant in three body colors red tilapia.(3)The genetic distance among the three populations ranged from 0.0121 to 0.1647.The genetic distance between pink and red spots was the closest and it was farthest between red and black spots.Cluster analysis also showed that pink and red spots were clustered into one group,black spots was clustered alone.SPSS 19.0 software was used to analyze the effect of microsatellite loci on body weight,body height,body length and body thickness of the red tilapia.The results showed that GM542 and body thickness was significantly related,UNH874 and body length and height were significantly related,UNH899 and body weight,body height and body thickness had significant correlation,UNH999 and body weight and height had significantly correlation,while UNH906,UNH971,UNH995 and body weight,body height,body length,body thickness were also significantly related.The results may contribute to QTL trait of the fish growth and further develop the technology of marker-assisted breeding.