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Odhad genetické variance užitkových vlastností kapra obecného s cílem předpovědět potenciál selekčního šlechtění v rybničních podmínkách chovu
PRCHAL, Martin
The main aim of this thesis was to study the genetic variation of several performance traits under pond management conditions and to estimate future perspective of sustainable selective breeding program in common carp. In the present study, Amur mirror carp (AM) and Hungarian synthetic mirror carp (HSM) were used. Most of the studied performance traits showed sufficient genetic variation (h2 = 0.12 1.0), suggesting a good potential for genetic improvement of the traits through selective breeding. It was shown that selection of common carp under pond management conditions should be optimally applied after the second overwintering. Winter survival is often a bottleneck for common carp production. As a result, the genetic background of winter survival and traits that might be correlated to the survival was studied. Main focus was given to the muscle fat and body weight and their dynamics through winter period and successive third growing period. It was found that selection for i) lower fat content before and after winter, ii) lower decrease in muscle fat content and/or body weight during winter, iii) higher condition factor may lead to better survival during both winter and third growing period and growth of fish during the third growing season. Unfortunately, direct selection for slaughter yields is impossible on live breeding candidates. Therefore, morphological predictors that can be measured in vivo are considered as an interesting alternative. As a result, external and internal measures were combined on 1553 fish by linear regression to predict log-log residuals (Logr) of slaughter yields. It was found that the accuracy of the prediction of slaughter yields may be solid. From the genetic point of view, model-predicted (h2 = 0.48 0.63) and even individual predictors (h2 = 0.34 0.72) of slaughter yields were highly heritable and favourably genetically correlated to the Logr yields. Hence, selection on trait predictors has an interesting perspective for genetic improvement of slaughter yields in common carp. Furthermore, genetic parameters of fillet fatty acid content and performance traits in market size common carp cultured under semi-intensive pond conditions were estimated. For flesh FA composition analysis 158 individuals were processed. Heritability estimates of total muscle fat, some FA groups and most performance traits were moderate to high (0.23 0.62). Interestingly, genetic correlations showed that genetic improvement of growth via selective breeding under Central European pond conditions without changing the production technology would very likely negatively affect carp flesh quality with respect to FA composition. Finally, restriction-site-associated DNA sequencing (Rad-seq) was used to identify and genotype single nucleotide polymorphism (SNP) markers for subsequent parentage assignment, construction of a medium density genetic map (12,311 SNPs), and testing of efficiency of marker-assisted (MAS) and genomic selection (GS) for growth and Koi herpes virus (KHV) resistance. No genome-wide significant QTL was identified for growth. However, genomic prediction of its breeding value may outperform the traditional pedigree-based prediction, resulting in an 18% improvement in prediction accuracy. On the other hand, genome-wide significant QTL affecting resistance to KHV was identified on linkage group (LG) 44 explaining approximately 7% of the additive genetic variation. The presented results add further evidence supporting the application of selective breeding in common carp cultured even under traditional pond management conditions. However, it is evident that the rearing technology will need suitable modifications. In addition, real economic impact of selective breeding on carp culture should be verified by calculation of realized heritabilities, real genetic gains and the total fish biomass yield of genetically improved stocks from a pond area unit.
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Verifying the suitability of two different lines Amur mirror carp to produce commercial hybrids of common carp breed with M2 on maternity position - wide-area test
VOJTĚŠEK, Zbyněk
The main aim of this work was to compare the survival and growth of common carp hybrids using two lines of Amur mirror carp. The test was created using the top cross breed with M2 on the maternity position. On the maternal line were crossbreeded males M2 (for the production of pure breed to verify the heterosis effect), the Nordic mirror carp M72, and two lines of Amur mirror carp (Alp - bred in Pohořelice and Alv - bred in Vodňany). As a control, the breed of hybrid Ropšín scaly carp and carp Tataj were used. The test was conducted at five locations from planting of the yolk sack (K0) until rearing up to the market size K3. During rearing regular catches were carried out, in order to control the growth and survival. After the subsequent determination of the corrected weight and survival for better quality of evaluation were determined. Consequently, some differences were found between the breeds and heterogeneous effect was fixed. After evaluating the test, where the lines crossed on the parent breed M2 achieved better results than pure-bred lines, I would not recommend this line for commercial breeding. In contrast, both lines of Amur mirror carp could be very well used for commercial farming, mainly due to higher resistance of hybrids to KHV.
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Comparison of biometrical and slaughtering indicators of crossbreeds of common carp with using two different breeds of Amur mirror carp
PRCHAL, Martin
The objective of this thesis was to compare biometrical and slaughtering indicators of common carp crossbreeds using two different breeds of Amur mirror carp in performance testing. We applied top-crossing for the test establishment, using the Hungarian mirror carp (M2) on the maternal position. Males of Hungarian mirror carp (for the production of purebreed), Northern mirror carp (M72) and two breeds of Amur mirror carp (ALP ? bred in Pohořelice, ALV ? bred in Vodňany) were crossed on this breed and hybrids of scaly phenotype between Ropsha (ROP) and Tata carp (TAT) were used as a control group. The performance testing started in ponds (in the total of five localities) in the semi ? intensive way of management by releasing yolk sac fry (K0) and its subsequent rearing to the market size (K3). The performance test was completed in ponds after the third year of testing and the tested groups of fish were evaluated for biometrical and slaughtering indicators. In the overall evaluation of the edible parts of the body (processed body and fillets) by the ANCOVA method was not found a statistical difference among the mirror tested groups of fish. The only exception was the proportion of fillets without skin, which was significantly higher in the hybrid M2 x ALP than in breed M2, therefore I would not recommend this breed (M2) to commercial breeding. When comparing my results with other publications, the hybrid M2 x M72 could be used for commercial breeding together with the two hybrids of Amur mirror carp, who not only achieve high yield of edible parts of the body, but also the earlier tests confirmed higher growth, better survival and resistance to the KHV virus.
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