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31.
马氏珠母贝选系F_2早期选择反应和现实遗传力估计 总被引：9，自引：1，他引：8
对马氏珠母贝基础群体进行持续选择建立选系F2,比较了选系F2与对照群体早期生长差别,并估计了选择反应和现实遗传力。结果表明,在第8、14、21和35天,选系F2的平均壳长显著大于对照群体(P<0.05)。在第8、14、21和35天,选择反应和现实遗传力变化范围分别为0.63～0.89和0.36～0.51。本研究表明利用群体选择可以明显改良马氏珠母贝养殖群体的生长性状。 相似文献
32.
Estimates of genetic and phenotypic parameters for weight and length in Paralichthys olivaceus (Temminck et Schlegel) 总被引：1，自引：0，他引：1
The complete diallel cross design was employed to estimate the genetic parameters of the growth of Japanese flounder (Paralichthys olivaceus). A total of 60 full-sib families were cultivated and two growth-related traits, body weight (BW) and body length (BL), were examined at average 2, 3 and 8 months of age respectively, with 1 800 individuals measured in each age group (30 per family). Based on the additive-dominance-maternal-effect genetic analysis model, the restricted maximum likelihood approach was used to estimate various (co)variance components. The results showed that narrow-sense heritability estimates of BW and BL were respectively:0.29±0.01 and 0.22±0.02 at 2 months of age, 0.32±0.02 and 0.30±0.04 at 3 months of age, 0.48±0.04 and 0.40±0.05 at 8 months of age; broad-sense heritability estimates were respectively:0.44±0.02 and 0.54±0.04 at 2 months of age, 0.35±0.01 and 0.36±0.03 at 3 months of age, 0.49±0.03 and 0.45±0.04. All heritabilities were statistically significant (P <0.05). Additive genetic correlations between BW and BL at 2, 3 and 8 months of age were consistently positive and highly significant (P <0.01):0.93±0.02, 0.95±0.03 and 0.92±0.03 respectively. Maternal effect was significant (P <0.05) only at 2 months of age, and was not detected at 3 and 8 months of age. According to the heritability estimates, the mass selection strategy should be efficient for the breeding of Japanese flounder. 相似文献
33.
大菱鲆(Scophthalmus maximus)家系选育 F2 早期选择反应和现实遗传力估计 总被引：1，自引：1，他引：0
为了评估大菱鲆选育F2的早期育种效果,采用3种方法,即,Ⅰ:比较F2选择系和对照系的最小二乘均值,Ⅱ:比较连续2代(F1和F2)选择系目标性状间的育种值,Ⅲ:比较F2选择系和对照系的育种值,估测了6月龄大菱鲆体重的选择反应,并进而分析了现实遗传力和遗传增益。结果表明,3种方法的选择反应估测值存在一定差异,其相应估测的现实遗传力和遗传增益也不相同;3种方法估测选择反应、现实遗传力和遗传获得的均值分别为3.1983±0.5880、0.2941±0.0531和8.70±1.60,显示出足够大的早期选择反应、中等的现实遗传力和较低的遗传获得,预示利用家系选育对大菱鲆进行遗传改良能够取得良好的育种成效,同时,这些群体还有很大的遗传改良潜力。 相似文献
34.
以虹鳟(Oncorhynchus mykiss)优良品系选育群体作为试验群体,采用单性状动物模型估计头长、体长、体高、体厚、尾柄长、尾柄高、背吻距、背鳍基长等8个主要体尺性状的遗传力。结果显示,上述8个性状的遗传力在0.131—0.313之间,多为中等或偏低遗传力,其中背鳍基长遗传力最低,为0.131±0.039,体高遗传力最高,为0.313±0.086。采用皮尔逊相关法估计上述性状之间的表型相关,结果显示,上述性状间表型相关变化范围为0.016—0.815。采用两性状动物模型估计上述性状间的遗传相关,结果表明,上述性状间遗传相关变化范围为0.065—0.866。在本研究中,比较分析表型和遗传相关结果发现,虽然体厚与尾柄长的表型相关最低,仅为0.016,相关性不显著(P0.05),但是遗传相关为0.247,似然比检验(likelihood ratio test,LRT)统计分析达到显著水平(P0.05)。体厚与背鳍基长的表型相关为0.647,t检验达到显著水平(P0.05);但遗传相关仅为0.305,LRT统计分析未达到显著水平(P0.05)。上述结果说明,在该群体中各体尺性状的表型相关和遗传相关水平不完全相同,在设计育种方案时应综合考虑各个性状间的表型相关及遗传相关。 相似文献