| The Siniperca chuatsi is one of the commercially important freshwater species mainly distributed in East Asia. Since1980s, the mature artificial propagation technology of create good conditions for large-scale cultivation. Unfortunately, the wild Siniperca chuatsi population is declining due to overexploitation and environmental pollution in their habitat, which could also cause the decline of genetic diversity. Artificial reproduction and selective breeding programmes have been undertaken to meet market demand of Siniperca chuatsi. In present study, effects of9morphometric attributes on body weight of three culture species of Siniperca chuatsi were analyzed, though the means of correlation analysis, multiple regression and path analysis; Using curve simulation and principle component analysis test the growth and development model of Siniperca chuatsi during1-6months. And the Siniperca chuatisi’s genetic structure and genetic diversity analysis was tested by five pairs of microsatellite primers. The results of this study are shown as follows:1. Mathematical analysis of effects of morphometric attribute on body weight of Siniperca chuatsiEffects of9morphometric attributes on body weight of three culture species of mandarin fish were analyzed, using correlation analysis, multiple regression and path analysis. Data of body weight (Y), total length (X1), standard length (X2), body depth (X3), head length (X4), eye diameter (X5), trail length (X6), caudal peduncle length (X7), caudal peduncle depth (X8) were collected in this study. Results of correlation analysis showed that there were significantly correlations between most of morphometric traits and body weight (P<0.01). According to the regression coefficient test, there was significant difference between different species and we set up multiple regression equation partly to estimate the body weight. Path analysis results indicated that total length (X1) and body depth (X3) bared strong direct effect on body weight (Y), and their path coefficients (Pi) and determination coefficient (di) were decreased as the time increased. The comprehensive decision coefficient of total length (X1) and body depth (X3) were maintain stability, which declared that total length (X1) and body depth (X3) could well predict body weight. This paper provides theoretical evidence and perfect measure target for breeding of Siniperca chuatsi in aquaculture.2. The fitting growth model and principal components analysis of morphological traits of the artificial selection groups of Siniperca chuatsi at the early ageIn order to understand the growth and development rules of the artificial selection species group of Siniperca chuatsi at the early age, the Body Weight (BW), Total Length (TL), Body Length (BL), Body Depth (BD), Head Length (HL), Caudal Peduncle Length (CPL) and Caudal Peduncle Depth (CPU) of70individuals randomly sampled during1～6month age. The growth data were analysis and fitted with linear models and the power growth model was performed to find the relationship between body weight and total length. Results showed that the relationship between body weight and total length was:W=0.013Z3.022(R3=0.994) and b=3.022, which mean the early growth of Siniperca chuatsi was isogony. That was also substantiated by the growth of total length and body depth, so we can use the model to predict growth. Principle components analysis results showed that contribution rate of length and the body weight factor for morphological traits was69.398%,69.672%,48.019%at the two-month-age, four-month-age and six-month-age, which revealed that the length and the body weight factor could become the selective indicator of morphological traits for the Siniperca chuatsi. The other two principal components were the tail factor and the body shape factor. The results will help to know the early growth and development rules of Siniperca chuatsi and to supply guideline to selected breeding.3. Genetic structure and genetic diversity analysis of the artificial selection populations of Siniperca chuatsiIn this study, five pairs of microsatellite primers were used to detect the genetic diversity and genetic distance in the artificial selection population and the wild population of Siniperca chuatsi. Observed heterozygosity (Ho), expected heterozygosity (He) values, polymorphic information (PIC) and number of effective alleles (Ne) were all determined. The observed genetic diversity was in the order:CJ> QY> FS, which showed the selective breeding could reduce the genetic diversity of Siniperca chuatsi. Genetic distance between QY and CJ (value0.3476) was shorter than Genetic distance between FS and CJ (value0.4238). Comprehensive the above results, QY group have the advantage of variety breeding and artificial breeding than FS group. |
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