首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 734 毫秒
1.
Reciprocal differences have been observed widely for given traits in fish breeding programs, but maternal and paternal effects and heritable extranuclear genetic effects have often been omitted in the evaluation of genetic variance. In this study, we have applied a mixed genetic model to conduct a complete diallel cross using three varieties of red common carp (Cyprinus carpio L.), namely, C. carpio. var. singuonensis, C. carpio var. wuyuanensis and C. carpio var. color. Parental and direct (additive and dominance) genetic effects for growth-related traits at 8 and 20 months post-hatch were analyzed. At 8 months post-hatch, only significant additive and dominance variances were observed, while maternal and paternal variances were low and non-significant in the traits evaluated: body weight, total length, standard length, pre-dorsal height, pre-dorsal width, caudal peduncle length, and caudal peduncle height. At 20 months post-hatch, with the exception of significant additive and/or dominance variances, maternal variances were significant for the traits of body weight, pre-dorsal height, pre-dorsal width, and caudal peduncle height, and the paternal variance was significant only for total length. The maternal effects in the common carp had greater genetic influence on offspring than the paternal effects. Female C. carpio var. wuyuanensis were more suitable as brooders than males, but both female and male C. carpio var. color can be used as brooders according to breeding programs of improved traits. Cyprinus carpio var. singuonensis was the worst brooder of the three varieties of common carp evaluated.  相似文献   

2.
Developmental genetic analysis was conducted for body weight, total length, standard length and body height in red common carp by a mixed genetic model with additive–dominance effects, based on complete diallel crosses made by Xingguo red common carp (Cyprinus carpio var. singuonensis), purse red common carp (Cyprinus carpio var. wuyuanensis) and Oujiang color common carp (Cyprinus carpio var. color). Unconditional genetic analysis revealed that the traits of body weight, total length and standard length were mainly controlled by dominance effects before June but by additive effects after June, which suggests a high potential for heterosis during the early developmental period and an opportunity for selection during the late developmental periods for common carp. Through conditional genetic analysis, lots of new expression of genes of additive effects for body weight, total length and standard length existed during April to August and significant new expression of genes from dominance effects for these three traits at the other period. New expression from additive and dominance effect genes for body height occurred intermittently during the ontogeny. The conditional genetic procedure is a useful tool to understand the expression of genes controlling developmental quantitative traits at a specific developmental period (t − 1 → t) during ontogeny. It is also important to determine the appropriate developmental period (t − 1 → t) for trait measurement in developmental quantitative genetic analysis in fish.  相似文献   

3.
红鲤生长性状的上位性遗传效应分析   总被引：8，自引：0，他引：8       下载免费PDF全文
运用加性-显性-上位性遗传模型及其分析方法,研究了兴国红鲤(Cyprinus carpiovar.singuonensis)、荷包红鲤(C.carpiovar.wuyuanensis)和瓯江彩鲤(C.carpiovar.color)的双列杂交子二代F2的体质量和10个形态性状(全长、体长、体高、体宽、头长、吻长、眼径、眼间距、尾柄长和尾柄高)的上位性遗传效应。结果表明,除体高外,其余性状均存在不同程度的加性×加性上位性方差,其中体质量、全长、体长、头长、吻长和尾柄长的加性×加性上位性方差达显著水平(P<0.05);这10项性状的上位性方差占总遗传变异量的百分率为:体质量11.4%、全长22.6%、体长14.0%、体宽8.3%,头长24.2%、吻长17.5%、眼径12.9%、眼间距23.1%、尾柄长5.4%和尾柄高20.1%;通过3种红鲤亲本的遗传育种效应预测发现,瓯江彩鲤的加性和上位性效应能显著增加后代的体质量、全长和体长,而兴国红鲤和荷包红鲤的加性和上位性效应能显著降低后代的体质量、全长和体长。上位性遗传效应在鱼类数量性状的遗传育种中具有较重要作用。[中国水产科学,2006,13(4):573-578]  相似文献   

4.
A quantitative genetic analysis was undertaken to estimate the genetic parameters for morphological traits associated with axial growth in Japanese flounder. Three year classes (2009, 2010, 2011) that included a total of 47 full-sib families were produced. At 180 and 360 days of age, six morphological traits that included total length, body length, head length, trunk length, caudal peduncle length and caudal fin length were measured on 1,185–1,981 individuals per year class. Based on these traits observed, fifteen length ratio traits were constructed as well. The phenotypic analysis showed that coefficients of variation for the caudal peduncle length and the ratio of it to other length traits had large variation relative to the other traits analyzed. Genetic variations in axial growth of Japanese flounder were revealed by using a single-trait animal model with the fixed, additive genetic and full-sib family effects. All analyzed traits exhibited moderate to high heritabilities, ranging from 0.33 to 0.80. Heritability was higher at 180 days of age than at 360. The current results for estimating genetic parameters demonstrated that these traits related to axial growth could be improved with family breeding in Japanese flounder.  相似文献   

5.
以吉富罗非鱼与奥利亚罗非鱼为繁育亲本,采用完全双列杂交繁育4组F1,将初始规格基本一致的4组罗非鱼饲养100 d后,运用“加性-显性”遗传分析模型,分析了4组F1罗非鱼8个生长相关性状杂种优势、遗传效应以及与性状间的相关性.结果表明:(1)F1群体平均优势为0.129 4～0.368 4.除尾柄长超亲优势较大外,其他性状的群体超亲优势较小或表现出负向超亲优势.(2)8个性状的广义遗传率(HB)为0.714 2～0.995 3,表明加性效应和显性效应对性状的遗传变异影响极显著(P＜0.01).除尾柄长外,其他性状的狭义遗传率(HN)介于0.469 4～0.737 9,表明加性遗传方差在表型方差中所占比率较高.(3)体质量、全长、体长、体高、体宽、头长、尾柄长、尾柄高性状之间表型相关在0.776 6～0.999 7范围内,而遗传相关在0.994 1～1.000 0之间,表明这些性状间都存在极显著的正相关.取样结束后,采用3.95×106 CFU/mL的海豚链球菌菌液进行腹腔感染,吉富罗非鱼自繁组F1代12 h后出现死亡,而奥利亚罗非鱼自繁组F1192 h后才出现死亡.384 h后,吉富罗非鱼自繁组F1死亡率为40％,正反交组F1分别为20％和23.3％,奥利亚罗非鱼自繁组F1死亡率最低,为6.67％.研究结果表明,除尾柄长外,杂交F1的其他性状不具备超亲优势,然而杂交可以提高选育后代的抗病力.  相似文献   

6.
For body weight (BW) and morphological traits measured repeatedly during growth in Japanese flounder, random regression models (RRMs) were constructed to genetically analyse growth curves and relative growth of morphological traits to BW or body length (BL). In the RRM of growth curves, genetic effects were optimally modelled using Legendre polynomials of two orders for six growth traits. Family and permanent environmental effects remained constant for morphological traits, whereas family effects changed linearly for BWs. During the measuring periods, the heritabilities of the traits increased with age and ranged from 0.256 to 0.843 for BW, 0.379 to 0.806 for body height, 0.338 to 0.773 for BL, 0.286 to 0.665 for head length, 0.159 to 0.708 for length of caudal fin and 0.335 to 0.774 for width of caudal peduncle. Genetic correlations for each trait decreased with increased lag in days of age. In the RRM of relative growth, all morphological traits analysed were significantly associated with BW and BL. The heritabilities for the allometries of morphological traits to BWs ranged from 0.251 to 0.755, whereas those to BLs ranged from 0.412 to 0.871. The majority of genetic correlations among these allometry scalings were negative. These estimated parameters can be utilized to not only guide the efficient selection of traits, but also to genetically regulate synchronous growth of body shape with BW in Japanese flounder.  相似文献   

7.
草鱼生长性状的遗传参数和育种值估计   总被引：2，自引：0，他引：2  
利用草鱼(Ctenopharyngodon idellus)生长性状选育核心群亲本,采用人工授精方式构建21个全同胞家系,并选用动物模型对16月龄草鱼生长性状进行遗传参数和育种值估计。结果显示,草鱼选育种群的生长性状存在丰富变异。采用约束极大似然法估计方差组分,发现草鱼体重、体长和体高性状的遗传力分别为0.39,0.47,0.21,属于中高遗传力;肥满度性状遗传力为0.11,属于低遗传力;4个性状的共同环境效应值相近且较小,范围为0.07~0.17。采用两性状动物模型分析相关性,发现体重、体长和体高性状间表型和遗传相关系数均达到高度正相关(r=0.88~0.97),而肥满度性状与三者间相关系数接近零,只与体高性状存在一定遗传正相关(r=0.43)。结合各性状遗传变异系数和相对遗传进度,分析表明,以体重为目标性状可便捷有效地改良草鱼生长性能。采用最佳线性无偏估计法预测个体育种值,发现4个性状育种值与表型值的相关系数范围为0.77~0.93。基于单性状育种值和表型值分别进行个体选择,按10%留种率,各性状选留个体相同率为68.75%~81.82%,秩相关系数范围为0.19~0.81,两种选择方式显示出较大差异,且差异大小与性状遗传力成反比例。本研究为草鱼生长性状选择育种提供了理论依据和技术支撑。  相似文献   

8.
Twelve paternal half-sib families (or 36 full-sib families) of the pearl oyster, Pinctada fucata martensii (Dunker), were produced according to the requirements of hierarchical genetic mating design. A total of 4320 individuals, aged 15 months, were measured for seven growth-related traits. Predicated upon the additive-dominance genetic analysis model, varying genetic variance components and then heritabilities of the growth-related traits of interest were estimated using analysis of variance. Results showed that seven growth-related traits had larger additive genetic variances (P<0.05); the dominance genetic variance of shell weight (SW) was smaller (P>0.05), the dominance genetic variances of other six traits were all larger (P<0.05). Narrow- and broad-sense heritabilities for the seven traits were, respectively, 0.64 ± 0.10 and 0.78 ± 0.12 for shell length, 0.49 ± 0.06 and 0.63 ± 0.09 for shell height, 0.38 ± 0.14 and 0.54 ± 0.16 for shell breadth, 0.41 ± 0.17 and 0.56 ± 0.11 for hinge length, 0.53 ± 0.11 and 0.68 ± 0.08 for body weight, 0.35 ± 0.07 and 0.55 ± 0.08 for tissue weight and 0.67 ± 0.10 and 0.75 ± 0.16 for SW. All heritability estimates were statistically significant (P<0.05). According to these results, the mass selection procedure is suggested for the breeding of P. martensii.  相似文献   

9.
Phenotypic and genetic parameters were estimated for three body traits (harvest weight, carapace length and standard length) and for adult male morphotypes of the giant freshwater prawn Macrobrachium rosenbergii in a fully pedigreed synthetic population in India. The data set included 9,173 progeny produced over four generations from 162 sires and 234 dams. Variance components and genetic parameters were estimated fitting an animal model using the residual maximum‐likelihood methodology. The heritabilities for harvest body weight (HW), carapace length (CL) and standard length (SL) were moderate (0.22 ± 0.056, 0.22 ± 0.055 and 0.25 ± 0.059 respectively). The common environmental effects for HW, CL and SL were 0.10 ± 0.020, 0.08 ± 0.018 and 0.10 ± 0.021 respectively. As M. rosenbergii is sexually dimorphic, we estimated heritabilities within each sex. Heritability of HW in females (0.27 ± 0.068) was greater than that in males (0.15 ± 0.057). CL and SL followed the same pattern. The occurrence of male morphotypes is a unique characteristic of adult populations of M. rosenbergii. Populations from culture ponds exhibit a wide range of sizes. To examine whether there was a heritable component in male morphotype frequencies, we treated male morphotypes as traits. The additive genetic variance (and hence the heritability) was zero for male morphotype, indicating that selective breeding to increase the proportion of desirable male morphotypes would not be effective. The genetic correlations among body traits were all positive, high and approaching unity. The results are discussed in relation to selection plans for the giant freshwater prawn.  相似文献   

10.
Asian sea bass (Lates calcarifer) is one of the most important marine food fish species in Asia and Australia. To estimate the reproductive success of broodstock and heritabilities of growth‐related traits, two independent full‐factorial crosses (PI and PII) were created by crossing 10 males and 10 females. At 90 days post hatch (dph), the body weight (BW) and total length (TL) of 804 individuals from PI and 900 individuals from PII were measured and tissues samples of each fish were collected. Parents and offspring were genotyped with nine polymorphic microsatellites. Out of 1704 offspring from the two crosses, 98.7% were assigned to their parents. In PI, 19 of 20 parents produced offspring, while in PII, only five parents contributed to offspring. Low contribution of parents to offspring could lead to reduced genetic variation in the next generation. Heritabilities for growth‐related traits were estimated using the pedigrees reconstructed using microsatellite genotypes. The estimates of heritability were 0.22±0.16 and 0.25±0.18 for BW, 0.31±0.14 and 0.24±0.21 for TL and 0.22±0.22 and 0.15±0.09 for Fulton's condition factor in the two crosses respectively. Body weights at 90 dph and at harvest (289 dph) were significantly correlated (r=0.601, P<0.01). Therefore, growth‐related traits could be improved by exploiting additive genetic effects through selective breeding, and broodstock candidates could be selected early in the production cycle.  相似文献   

11.
The variance components of additive effects and genetic correlations of body weight (BW) and body measurement traits were estimated in a freshwater strain selected for large size in a breeding program for rainbow trout, Oncorhynchus mykiss, in China. Phenotypic data were collected for BW and measurement traits from 2362 individuals with a two‐generation pedigree, and the average information‐restricted maximum likelihood method was used for the genetic analysis. The genetic parameters of BW were estimated at three time points (550, 850, and 1000 days post‐fertilization [dpf]), showing high heritability in a range from 0.33 to 0.98. However, the heritability estimates of total length (TL) showed lower values ranging from 0.05 to 0.51, with high standard errors. Genetic correlation between TL and BW was almost equal to unity at 550 dpf, and the genetic correlations between TL at 550 dpf and BW at two other time points were all positive and very high (ca. 0.95–0.99). These results indicate that BW and TL selected at 550 dpf had a direct positive effect on BW performance at 1000 dpf, which was 450 d before the date of the target trait observed.  相似文献   

12.
Shell thickness in mollusks is generally considered adaptive because of their effects on fitness. However, little is known about the genetic basis of shell thickness. This is important, because the response to selection and the subsequent adaptive microevolution of a trait, such as thickness is only possible when that trait exhibits additive genetic variation. Here, we estimated the narrow‐sense heritability (h2: ratio between additive genetic variance and phenotypic variance) for the traits ‘shell thickness’ and ‘shell length growth’ in a 34‐month‐old cohort of the mussel Mytilus chilensis obtained by using a half‐full sib design and grown in the field. Also, phenotypic and genetic correlations were estimated between both traits. We found that h2 showed significant values for shell thickness (0.294 ± 0.194) and length (0.731 ± 0.379). The phenotypic correlation between both traits was positive and significant; however, the genetic correlation between these traits was not. These results suggest both traits can evolve adaptively by selection, but because these traits did not show genetic correlation, it is possible that selection pressure affecting one trait may not affect the other.  相似文献   

13.
The aim of this study was to estimate the genetic parameters of the growth performance of clam Meretrix meretrix. As part of the breeding programme, 25 full‐sib families nested within eight half‐sib families were produced, planted out and tested to assess the heritability of the total body weight (TW), shell length (SL), shell height (SH) and shell width (SW) at different growth stages. Method of analysis was implemented using the Bayesian method based on the Multiple Trait using Gibbs Sampling under Animal Model program, which was used to estimate the (co)variance components of the traits and conduct genetic analysis. A total of 25 full‐sib families, each with 30–35 individuals within family, were used for the analysis. Significant positive genetic and phenotypic correlations between SL, SW, SH and TW with each other were observed. The growth traits showed high‐magnitude heritabilities, with values ranging from 0.64 to 0.85, which indicates that these traits should respond to selection and therefore should be included in genetic improvement programmes.  相似文献   

14.
Heritabilities and genetic and phenotypic correlations were estimated for body weight (BW), body length (BL), carapace length (CL), carapace width (CW) and carapace height (CH) of the Penaeus monodon from measurements on progeny at 6 months of age resulting from a nested mating design. Estimation was made on data from 41 full‐sib and 10 half‐sib families. The estimated heritabilities for these traits were 0.13–0.24, and the significantly phenotypic and genetic correlations were 0.81–0.94 and 0.88–1.00, respectively. The present results indicate that genetic improvement through selective breeding conducted on P. monodon might be feasible and would be an efficient method to obtain a positive response to selection.  相似文献   

15.
分子群体遗传学方法处理鲤形态学数据的适用性   总被引：1，自引：0，他引：1  
在鱼类形态学性状的数据处理分析中,主要利用数理统计分析软件进行形态学数据的聚类分析、主成分分析和判别分析,而随着现代分子生物学技术的发展,一系列分子群体遗传学数据分析方法和处理软件应运而生。为研究分子群体遗传学方法对鱼类形态学数据分析的适用性,实验以兴国红鲤、玻璃红鲤、荷包红鲤完全双列杂交产生的9个群体形态学数据为对象,比较了传统形态学方法与分子群体遗传学方法对鱼类形态学性状的分析效果。结果发现,两类方法的聚类分析结果一致;主成分分析的结果表明,传统形态学分析方法能反映个体间的形态差异,而分子群体遗传学方法则能更好地反映群体间的形态差异;判别分析结果显示,两类方法的综合判别率相当;利用STRUCTURE软件进行的遗传聚类分析结果也发现,两类方法所得的结果一致。研究表明,应用传统形态学方法与分子群体遗传学方法分析鲤形态学性状是一致的,分子群体遗传学方法处理鲤科鱼类形态学数据是可行的。  相似文献   

16.
Cadmium (Cd) compounds are widely distributed toxic environmental and industrial pollutants, and they may bring danger to growth and development of aquatic organisms. In China, the Oujiang color common carp, Cyprinus carpio var. color, is a very important fish, from an economic point of view, and is well used for fish culture in paddy fields. The purpose of this study was to show the low concentrations of cadmium-induced oxidative stress response and DNA damage in the livers of Cyprinus carpio var. color. Superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) in liver were measured after exposure to Cd levels (0.41, 0.52, 0.69, 1.03 and 2.06 mg/L, respectively) for 7 days and compared with the control groups. DNA damage, including indicators of damage percentage, DNA tail length (TL) and DNA tail moment (TM) were also analyzed by comet assays. Results showed that MDA and GSH levels in all treatment groups increased significantly relative to the controls (P < 0.01). Treatment with Cd at concentration of 0.41 mg/L increased SOD activity, while treatment with Cd at concentrations >0.41 mg/L inhibited SOD activities. DNA damage percentage, TL and TM also significantly increased when the Cd level was >0.41 mg/L. Positive correlations were also found between DNA damage levels and MDA levels (r = 0.74 for DNA damage percentage, r = 0.83 for TL, r = 0.84 for TM; P < 0.01 for all) as well as between GSH and MDA levels (r = 0.77, P < 0.01). These results strongly suggested that Cd-induced DNA damage in the livers of Cyprinus carpio var. color was due to lipid peroxidation and oxidative stress.  相似文献   

17.
Selection, either natural or artificial, induces an inter‐generational response only when the trait exhibits additive genetic variation. An index of additive genetic variation is narrow‐sense heritability (h2): the ratio between additive genetic variance and phenotypic variance. Here, we present narrow‐sense heritabilities for mass and size in the Chilean blue mussel Mytilus chilensis at different ages and in three different populations. We found that h2 changed with age and that maternal‐non‐additive variance was high, generating relatively low estimates of h2 in most cases. Our results, together with previous studies, suggest that genotype‐by‐environment interaction does not appear to play a significant role. However, we found that non‐additive and common environmental variance are important determinants of phenotypic morphological variation in body size in M. chilensis. Further studies are needed to establish the precise contributions of these sources of variation, to assess the real potential for response to selection.  相似文献   

18.
许氏平鲉不同月龄选育群体形态性状的主成分与通径分析   总被引：4，自引：1，他引：3  
为研究许氏平鲉不同月龄选育群体性状的生长规律特征及形态性状对体质量的影响,采用相关分析、主成分分析、通径分析和多元回归分析方法对12月龄、15月龄和18月龄许氏平鲉个体的全长、体长、头长、躯干长、体高、尾柄长、尾柄高和体质量8个性状进行分析。结果显示,各月龄许氏平鲉性状之间均呈现显著的正相关,其中以全长与体长的相关性最为显著。各月龄许氏平鲉的第一主成分均指向增长、增重因子;第二主成分有所不同,12月龄未提取第二主成分,15月龄和18月龄第二主成分分别指向躯干因子、尾柄因子。12月龄和15月龄许氏平鲉体长和体高对体质量的直接作用均最大(0.340、0.314和0.347、0.324),18月龄全长对体质量的直接作用最大(0.498),各性状对体质量决定程度与通径系数变化趋势一致。各月龄的不同形态性状对体质量最优回归方程的建立,能准确预测体质量的变化。研究表明,由于许氏平鲉生长阶段的不同,各性状的生长速率及所选形态性状对体质量的影响均存在一定差异,建议把体长和体高(12~15月龄)、全长(18月龄)作为育种工作的目标性状,达到有效提高选育效率的目的,为许氏平鲉的选育工作提供理论依据和技术参数。  相似文献   

19.
Insulin‐like growth factor‐I (IGF‐I) participates in the modulation of the cellular development, differentiation and proliferation in various vertebrate tissues. Therefore, variations in IGF‐I gene are good candidates as growth regulators. In this study, a novel 79‐bp insertion/deletion (I/D) polymorphism was identified in 3′‐flanking region of IGF‐I gene by polymerase chain reaction (PCR) and sequencing approaches in common carp Cyprinus carpio. To gain insight into the association of the 79‐bp I/D polymorphism with growth‐related traits, a total of 747 individuals from Heilongjiang carp Cyprinus cario haematopterus (YL) (n = 263), selective line of German mirror carp Cyprinus carpio L. mirror (JL) (n = 229), and cold‐resistance line of Hebao red carp Cyprinus carpio var. wuyuanensis (HL) (n = 255) were genotyped. The DD genotype of the polymorphism was significantly associated with higher body length (135), body weight (325, 385, and 445 days), net weight (445 days) and lower overwintering body loss rate in JL. In addition, in pooled population (YL+JL+HL), fish with DD genotype also showed significantly higher body weight (445 days) and net weight (445 days) than those with II genotype. Taken together, these results suggest that the novel polymorphism in IGF‐I gene could be considered as a potential genetic marker for selection of growth performance in common carp.  相似文献   

20.
To estimate genetic parameters of growth traits in Japanese flounder Paralichthys olivaceus, full-sib and half-sib families were produced in three consecutive years at the Beidaihe Central Experiment Station in China. Each year 8–28 families were produced. The body weight, body length and body depth at 180, 240, and 360 days of age were measured for 5,224 individuals. Four animal models were used to examine the phenotypic variation of growth traits and were compared using the likelihood ratio test. The results showed that estimates for additive genetic effect heritabilities varied greatly depending on the model, trait and age. The maternal effect had a significant impact on phenotypic variation only for body depth at 180 days of age, which explained 49% of the phenotypic variance. The ratio of full-sib effect to phenotypic variation ranged from 0.09 to 0.22. Growth traits all exhibited low heritability (0.13–0.39), indicating that there is the potential for family selection breeding for these traits in Japanese flounder. Using the full model with the fixed, full-sib family, additive and maternal genetic effects, genetic correlations among the three traits for fish of the same age were estimated to be more than 0.80. Generally, the genetic correlations gradually increased as age increased.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号