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牙鲆是太平洋西岸海水养殖、捕捞和自然增殖的主要鱼类,但是人工养殖病害多、生长慢,针对这一问题,从2003年开始开展了牙鲆选择育种。本文利用筛选和培育的F1、F2代牙鲆家系核心群体,构建了F3代家系52个,在生长到196d时,对家系1 560尾鱼苗全长、体宽、体质量、全长日增量和体重日增量5个生长性状进行测量和计算,获得7 800个数据。采用“加性-显性”线性模型、最小范数二阶无偏估计法(MINQUE)对以上生长性状的边际平均值、加性方差分量、显性方差分量、随机方差分量、狭义遗传力、广义遗传力、亲本加性效应、杂交随机效应等遗传参数进行了评估。结果显示:1202、1206、1226和1211家系以上生长性状的边际平均值同时显著高于其他家系。以上5个生长性状的加性方差分量比率为(0.099±0.01)~(0.24±0.02),显性方差分量比率(0.30±0.02)~(0.31±0.02),随机方差分量比率(0.48±0.02)~(0.61±0.01),5个性状狭义遗传力0.099~0.24,广义遗传力0.38~0.54,以上遗传参数均达极显著性水平(P<0.01)。综合比较18个亲本5个性状的加性效应预测值,发现F0917、F0908、F0905、F0915、F09125和KS(韩国牙鲆)亲本在5个性状上都具有极显著的正向效应(P<0.01),其他亲本5个性状都不同程度的表现为显著(P<0.05)或极显著(P<0.01)的负向加性效应。对42个杂交组合显性随机效应进行预测,D(2×6)、D(2×18)、D(3×4)、D(7×12)、D(7×14)和D(8×13)6个杂交组合在5个性状上都表现为极显著(P<0.05)正效应,利用这些杂交组合建立家系将促进牙鲆以上5个性状的生长。本文研究结果,为牙鲆优良家系的建立及新品种的培育初步筛选出了性状优良的亲本、杂交组合和家系,同时为牙鲆进一步选择育种提供了理论和技术依据。
Paralichthys olivaceus is the main fish in the west coast of the Pacific Ocean for marine aquaculture, fishing and natural breeding. However, there are many diseases of artificial breeding and slow growth. To solve this problem, flounder is selected for breeding since 2003. In this paper, 52 F2 families were selected from F1 and F2 generation screened and cultured families. The full-length, body width, body weight, total daily increment And body weight increment 5 growth traits were measured and calculated, 7 800 data were obtained. The marginal mean value, additive variance component, dominant variance component, stochastic variance component, narrow sense inheritance of the above growth traits were calculated using the “additive-dominance” linear model and MINQUE of the minimum norm Force, general heritability, parental additive effect, hybridization random effects and other genetic parameters were evaluated. The results showed that the marginal mean growth traits of 1202, 1206, 1226 and 1211 pedigrees were significantly higher than those of other pedigrees at the same time. The ratio of additive variance components of the above five growth traits was (0.099 ± 0.01) ~ (0.24 ± 0.02), the ratio of dominant variance components (0.30 ± 0.02) ~ (0.31 ± 0.02) and the random variance component ratio (0.48 ± 0.02) ~ (0.61 ± 0.01). The heritabilities of the five traits were 0.099 ~ 0.24 in the narrow sense and 0.38 ~ 0.54 in the heritability. The above genetic parameters reached the extremely significant level (P <0.01). By comparing the predictive value of additive effect of five traits in 18 parents, we found that the parents of F0917, F0908, F0905, F0915, F09125 and KS had a significant positive effect on five traits (P <0.01 ). The other five traits all showed significant (P <0.05) or extremely significant (P <0.01) negative additive effects in varying degrees. D (2 × 6), D (2 × 18), D (3 × 4), D (7 × 12), D (7 × 14) and D (8) were predicted for the 42 random combinations. × 13) Six hybrid combinations showed significant (P <0.05) positive effects on all five traits. The establishment of pedigrees using these hybrid combinations will promote the growth of more than five characters of Japanese flounder. The results of this study provide a theoretical and technical basis for the establishment of excellent pedigree and the cultivation of new cultivars of Paralichthys olivaceus, which have good characters of parents, cross combinations and pedigrees.