Genetic Effects Analysis On Growth And Physiological Traits In The Complete Set Lines Of Oujiang Color Common Carp (Cyprinus Carpio Var. Color)

Oujiang color common carp (Cyprinus carpio var. color), a common carp variantdistributing in the Oujiang River basin of our country, has been locally cultured formore than one thousands without systematic selection and genetic improvement.Oujiang color common carp is a special freshwater fish with richful nutrients anddelicious meat, as well as various color patterns, which are beautifully appearaed inornanmental (Koi) carp, imploying important biodiversity value and huge potentiality ofdevelopment and utilization in this fish. To date, some authors in China have beenconducting a serious of studies on genetics, selection and utilization resourcedevelopment, for example, several selective strains had been established and completeset line breeding has been carrying out. In these studies, developmental quantitativegenetics and genetic dynamics were analyzed for growth-related traits from thecomplete diallel crosses of the five seletictive lines in Oujiang color common carp,similarly, genetic effects analysis of physiological relative traits were conducted forbetter promoting genetic improment, especially complete set line breeding in Oujiangcolor common carp.1. Developmental quantitative genetics analysis of growth-related traits on Oujiangcolor common carpDevelopmental quantitative genetics imply the genetic effect dynamics ofquantitative traits in different development period. In this study, based on a completediallel cross with25combination made by the five selective lines of Oujiang colorcommon carp, a tatol of five growth-related traits (body weight, total length, standardlength, pre-dorsal height and pre-dorsal width) were monthly measured from juvenile toadult stages (commercial size). A mixed genetic model including additive, dominance,maternal and paternal effects was employed to analyze genetic effects (addictive effect,dominance effect, paternal effect and maternal effect) of five growth-related quantitativetraits in different development months. The results indicated these were significant(P<0.05or P<0.01) addictive, dominance and paternal genetic variances, but maternalgenetic variances were very lower and nearly closed to zero. Addictive genetic variances were higher than other genetic variances from August at adult stage, showingabsolutely dominant to other effects. Furthermore, the conditional genetic effectanalysis aslo indicated the high conditional addictive, dominance and paternal geneticfrom August at adult stage, implying the genes determining these genetic effects newlyexpressed during these periods. Conditional addictive geneticeffects display a relativelystable platform period from August, and accounted for the highest proportions ofphenotype variance (60.8%~68.3%), indicating the genes determining addictive effectsstably and dominantly expressed from August. The results of genetic correlationsanalysis showed that there were significant addictive correlations between the lastmonth and previous growth months for body weight, total length, standard length andpre-dorsal height (P<0.05), however, dominance correlations、paternal correlations andmaternal correlations were not detected. The partial significant dominance correlationsand paternal correlations were found for pre-dorsal width, but the addictive correlationwas the most important genetic correlation in this trait. Consequencely, the findingsshowed that additive genetic effect played a dominant role in Oujiang color commoncarp, implying the direct selection should be continuely conducted for Oujiang colorcommon carp from August.2. Observation and analysis of growth dynamics in Oujiang color common carpwith different pigmentation typesThe hybrids derived from a complete diallel cross of the five selective lines ofOujiang color common carp (Cyprinus carpio var. color) were used to observe andanalyze developmental dynamics of five growth-related traits (eg. body weight (BW),total length (TL), standard length (SL), pre-dorsal height (PDH) and pre-dorsal width(PDW) in the five pigmentation types of Oujiang color common carp, including wholered (WR), whole red with big black spots (RB), whole red small black spots (RS),whole white with big black spots (WB) and whole white (WW). The results showed thatthe same S-characteristics for growthwas found in the five pigmentation types of carp.The highest absolute growth rate (AGR) and special growth rate (SGR) was observedduring June and October indicating their faster growth sta ges during these months. Thefishes of RB and WB displayed higher growth rate than fishes of the other pigmentationtypes from juvenile stage, but the fish of WW was the slowest in growth. The relativehigh coefficient of variation (C.V=8%~35%) for body weight were detected in the fivepigmentation types of carp at each month. There were significant linear correlation forbody weight between each previous month and last month and the determinationcoefficients as gradually increased as growth (r2=0.0002~0.9936，P<0.01). Condition factors of the five pigmentation types of Oujiang color common carp from3.22to3.71before July in the second-year growth stage, then gradually increased to rough3.7afterJuly. Condition factors of WR was the highest at each month, however WW and WRshowed relatively low condition factors at each study month. The study provided atheoretical basis for further selective breeding of Oujiang color common carp.3. Genetic effects analysis of physiological and biochemical traits in Oujiangcolor common carpA additive-dominance mixed genetic model was used to analyze the genetic effectsof14physiological and biochemical traits of mating conbination from a diallel crosswith5selective lines at adult stage (commercial size). These traits included twobiochemical traits of superoxide dismutase (SOD) and peroxydase (POD),12physiological indicators of white blood cell (WBC)、red blood cell (RBC)、haemoglobin(HGB)、 hematokrit (HCT)、 mean corpuscular volume (MCV)、 mean corpuscularhemoglobin (MCH)、mean corpuscular hemoglobin concentration (MCHC)、red bloodcell distribution width coefficient of variation (RDW)、platelet count (PLT)、meanplatelet volume (MPV)、platelet distribution width (PDW) and phrombocytocrit (PCT).The results showed that additive variance were significant only for superoxidedismutase (SOD), but non-significant or nearly zero in the other traits. There weresignificant dominance variances for white blood cell (WBC)、red blood cell (RBC)、haemoglobin (HGB)、 mean corpuscular volume (MCV) and platelet count (PLT)(P<0.05), but they were not significant for other traits. The heritabilities in the narrowsense for these physiological and biochemical traits were very low, but the heritabilitiesin the broad sense were very high, which showed thesetraits were affected bydominance effects and environmental condition，The predicted values for parentalgenetic effects, indicated that the dominance effects was dominant in these selectivelines with the exception of whole white, the parent of whole white was not goodused as genetic parents for genetic improment in these traits.