Families Selection And Genetic Analysis Of Growth Traits For Hyriopsis Schlegeli In The First Generation

The growthlaw of four growthtraits, which were respectively shell length, shell height, shell width and body weight were investigated in the research by taking Hyriopsis schlegeli as the experimental subject, the optimum growthmodel for above quantitative traits in Hyriopsis schlegeli was chosen from the five candidational growthmodels, Brody, von Bertalanffy, Gompertz, Logistic and Richards; The families was built with the healthy parents, growthperformances among 24 F1 families were compared by variance analysis, cluster analysis and residual analysis. The effects of morphometric on body weight for Hyriopsis schlegeli at four months (5 month, 7 month, 10 month and 15 month) were analyzed by correlation analysis and path analysis; Utilizing Derivative-Free Restricted Maximum Likelihood (DFREML) and animal model Best Linear Unbiased Prediction (BLUP), the animal additive effects were calculated, and the breeding value were predicted.The results showed that:1). In the first two years on the growthof Hyriopsis schlegeli, based upon Mallows' criterion of model selection, Brody model was most suitable to depicting the growthof shell length, shell height and shell width; von Bertalanffy model was the best in fitting and predicting the growthbody weight.2). There were significant differences in growthtraits between and within groups (P<0.01). The Fam57 (Family 57) had significant growthadvantage in the first 15 months at the shell length, shell height and body weight, and the family had the maximum absolute growthrate among 5 to 15 months; The Fam31 had significant growthadvantage in the first 15 months at the shell width, and the family had the maximum absolute growthrate among 5 to 15 months. The results of the cluster analysis indicated that Fam57 had best growthsuperiority, and Fam14,Fam28,Fam07,Fam58,Fam90, Fam79 had the lowest growthadvantage.3). Three correlation coefficients between each morphological characters and the weight achieved very significant difference levels (P<0.01). The shell length was most related with body weight, the shell width was secondly. The multiple regression analysis built the regression equations for each month. The equations were showed as following:The regression equation for 5 month:Y=-11.876+0.255X1+0.102X2+0.504X3The regression equation for 7 month:Y=-15.168+0.288X1+0.081X2+0.785X3The regression equation for 10 month:Y=-18.820+0.463X1+0.098X2+0.309X3The regression equation for 15 month:Y=-48.628+0.724X1+0.286X2+1.021X3The Y was body weight, X1 was shell length, X2 was shell height, X3 was shell width.4). The heritabilities for shell length was 0.7645, the heritabilities for shell height was 0.6805, the heritabilities for shell width was 0.4951, the heritabilities for body weight was 0.4992. Animals were ranked according to the estimate breeding value (EBV) to provide information for selection. The percent of the shellfishes from Fam57 among the top ten EBVs for each growthtraits was 80.00%,90.00%,80.00% and 30.00% respectively. Families were ranked according to their mean EBVs, the growthtraits of Fam27 and Fam57 were the top two families among the families. Fam02,Fam28,Fam40,Fam57,Fam73, Fam79; and the top thirty animals on the rank for the mean EBVs of the SL/SW main from Fam2,Fam73,Fam79, Fam90.