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Peter B Mather - One of the best experts on this subject based on the ideXlab platform.

  • estimates of strain additive and non additive genetic effects for growth traits in a Diallel Cross of three strains of giant freshwater prawn macrobrachium rosenbergii in vietnam
    Aquaculture, 2010
    Co-Authors: Nguyen Minh Thanh, Nguyen Hong Nguyen, Raul W Ponzoni, Nguyen Thanh Vu, Andrew C Barnes, Peter B Mather
    Abstract:

    Abstract Additive genetic, heterotic and strain reciprocal effects were estimated using a Diallel Cross of two local wild strains of the giant freshwater prawn ( Macrobrachium rosenbergii ) in Vietnam (Dong Nai and Mekong) and a third domesticated Hawaiian strain, newly introduced to Vietnam. While some minor heterotic outcomes were detected in specific Crosses, strain additive genetic and reciprocal effects were more significant sources of variation for all growth traits measured. Strain additive genetic effects were highest for the Hawaiian strain (+ 10.2%) and lowest for the Mekong strain (− 11.6%) for harvest body weight. A similar pattern of strain additive genetic effects was observed for carapace and standard length. Average heterotic outcomes for all growth traits were small and not significantly different from zero ( P  > 0.05), and ranged from + 0.7 for carapace length to + 1.5% for body weight. The reciprocal effect had a positive effect on growth rate, because Crosses between the Dong Nai (D) or Mekong (M) strains as dam and the Hawaiian (H) strain as sire grew faster than did their reciprocal Crosses (HD and HM). The relative high correlation between strain additive performance and total performance for all traits ( r  = 0.71 to 0.77) suggests potential for exploiting strain additive variation to improve M. rosenbergii culture stock via direct selection among strains. A breeding strategy for genetic improvement of giant freshwater prawn in Vietnam is discussed.

  • evaluation of growth performance in a Diallel Cross of three strains of giant freshwater prawn macrobrachium rosenbergii in vietnam
    Aquaculture, 2009
    Co-Authors: Nguyen Minh Thanh, Nguyen Hong Nguyen, Raul W Ponzoni, Andrew J Barnes, Peter B Mather
    Abstract:

    The giant freshwater prawn (Macrobrachium rosenbergii) is one of the most important crustacean species produced in inland aquaculture in many tropical and subtropical countries worldwide. The aim of the current study was to evaluate the growth performance of three strains of giant freshwater prawn that originated from geographically separated locations in a complete (3x3) Diallel Cross as a starting point for a stock improvement program for the industry in Vietnam. Crosses were established over two generations using two wild Vietnamese river populations (Dong Nai and Mekong) domesticated for the study and an introduced Hawaiian strain that had been in Culture for many generations. juveniles from nine strain combinations were produced using single-pair matings. Results after 15 weeks of grow-out in hapas showed that growth performance of the Hawaiian strain was best among the purebred strains and that certain Cross combinations grew significantly faster than purebred strains. Mean body weights of specific Cross combinations with Dong Nai or Mekong as dams and the introduced strain (Hawaiian) as sires were significantly heavier than those of Purebred Dong Nai or Mekong strains. While males reached heavier mean weights than females. male variation among the strains was obscured by social factors that produced different frequencies of male morphotypes (blue claw, orange claw and small males). Results suggest presence of potentially Valuable heterosis and possible impact of the direction of Cross. From a practical Viewpoint this Could be exploited upon by either, including different forms of Crossbreeding, or alternatively, by creating a composite Population for future selection. Potential problems and challenges encountered during the trials are discussed. (c) 2008 Elsevier B.V. All rights reserved.

Nguyen Hong Nguyen - One of the best experts on this subject based on the ideXlab platform.

  • additive genetic and heterotic effects in a 4 4 complete Diallel Cross population of nile tilapia oreochromis niloticus linnaeus 1758 reared in different water temperature environments in northern vietnam
    Aquaculture Research, 2016
    Co-Authors: Ngo Phu Thoa, Nguyen Huu Ninh, Nguyen T Hoa, Wayne Knibb, Nguyen H Diep, Nguyen Hong Nguyen
    Abstract:

    This study aims to estimate the strain additive genetic and heterotic effects on growth and survival in a 4 × 4 complete Diallel Cross-population of Nile tilapia. Mass spawning was practised in replicate hapas to simultaneously produce progeny of all Crosses for performance testing in three environments (in ponds at 20–30°C, in tanks at 15–20°C and in tanks at 20–25°C). A total of 6735 individually tagged fish were tested over a grow-out period of 278 days. Statistical analyses were carried out on 5097 body trait records available at harvest. ACross the test environments, the NOVIT4 strain exhibited the highest additive genetic values for both growth and survival (19% and 33% above the pure strain mean respectively). The heterosis effect was low and not different from zero for both traits. The ranking of strains with respect to their additive genetic values generally did not change between tank environments (15–20 vs. 20–25°C). The correlations of the additive genetic performance between tank environments were also high (0.84), suggesting that strain by water temperature interaction was likely not biologically important. By contrast, the differences in both performance and survival between pond and tank environments were statistically significant, indicating that this effect should be accounted for in future breeding programmes. The large additive genetic effect among strains coupled with the non-significant heterotic effects in our study suggest that future breeding programme in this population of Nile tilapia should be based on a wise choice of strain or by exploiting the additive genetic variation through selective breeding.

  • genetic evaluation of a complete Diallel Cross involving three populations of freshwater prawn macrobrachium rosenbergii from different geographical regions of india
    Aquaculture, 2011
    Co-Authors: Bindu R Pillai, Nguyen Hong Nguyen, Raul W Ponzoni, Kanta Das Mahapatra, Lopamudra Sahoo, P L Lalrinsanga, S Mohanty, Swagathika Sahu, Sovan Sahu, Hooi Ling Khaw
    Abstract:

    Abstract Estimates of additive genetic, reciprocal and average heterosis effects were obtained from a three by three complete Diallel Cross experiment for giant freshwater prawn Macrobrachium rosenbergii . The data were generated in two batches. Three populations were sampled from the states of Gujarat (West), Kerala (South West) and Orissa (East) in India. The two mating batches of Diallel Crosses were combined in the analysis. A total 4773 animals (2233 in Batch 1 and 2540 in Batch 2) were tagged with VIA (Visible Implant Alpha numeric tags). A total of 2545 animals (979 and 1566 from Batch 1 and 2, respectively) were harvested with readable VIA tags and were; therefore available for analysis. The fixed effects included in the models were test environment (ponds 1 or 2 in batch 1, ponds 3 or 4 in batch 2), sex (male or female) and batch (1 or 2). Age at harvest was fitted as linear covariate. The genotype effect was partitioned into additive, non additive and reciprocal Cross effects. Body weight, standard length and carapace length were recorded during tagging, sampling and harvesting. Estimates of additive genetic effect in the three stocks showed that the Kerala stock had greater body weight, carapace length and standard length, followed by Orissa then Gujarat. Average heterosis for body traits was low (3.1 to 6.3%) and not significantly different from zero. The results are discussed with respect to the choice of the most appropriate breeding strategy to improve the performance of M. rosenbergii in India.

  • estimates of strain additive and non additive genetic effects for growth traits in a Diallel Cross of three strains of giant freshwater prawn macrobrachium rosenbergii in vietnam
    Aquaculture, 2010
    Co-Authors: Nguyen Minh Thanh, Nguyen Hong Nguyen, Raul W Ponzoni, Nguyen Thanh Vu, Andrew C Barnes, Peter B Mather
    Abstract:

    Abstract Additive genetic, heterotic and strain reciprocal effects were estimated using a Diallel Cross of two local wild strains of the giant freshwater prawn ( Macrobrachium rosenbergii ) in Vietnam (Dong Nai and Mekong) and a third domesticated Hawaiian strain, newly introduced to Vietnam. While some minor heterotic outcomes were detected in specific Crosses, strain additive genetic and reciprocal effects were more significant sources of variation for all growth traits measured. Strain additive genetic effects were highest for the Hawaiian strain (+ 10.2%) and lowest for the Mekong strain (− 11.6%) for harvest body weight. A similar pattern of strain additive genetic effects was observed for carapace and standard length. Average heterotic outcomes for all growth traits were small and not significantly different from zero ( P  > 0.05), and ranged from + 0.7 for carapace length to + 1.5% for body weight. The reciprocal effect had a positive effect on growth rate, because Crosses between the Dong Nai (D) or Mekong (M) strains as dam and the Hawaiian (H) strain as sire grew faster than did their reciprocal Crosses (HD and HM). The relative high correlation between strain additive performance and total performance for all traits ( r  = 0.71 to 0.77) suggests potential for exploiting strain additive variation to improve M. rosenbergii culture stock via direct selection among strains. A breeding strategy for genetic improvement of giant freshwater prawn in Vietnam is discussed.

  • evaluation of growth performance in a Diallel Cross of three strains of giant freshwater prawn macrobrachium rosenbergii in vietnam
    Aquaculture, 2009
    Co-Authors: Nguyen Minh Thanh, Nguyen Hong Nguyen, Raul W Ponzoni, Andrew J Barnes, Peter B Mather
    Abstract:

    The giant freshwater prawn (Macrobrachium rosenbergii) is one of the most important crustacean species produced in inland aquaculture in many tropical and subtropical countries worldwide. The aim of the current study was to evaluate the growth performance of three strains of giant freshwater prawn that originated from geographically separated locations in a complete (3x3) Diallel Cross as a starting point for a stock improvement program for the industry in Vietnam. Crosses were established over two generations using two wild Vietnamese river populations (Dong Nai and Mekong) domesticated for the study and an introduced Hawaiian strain that had been in Culture for many generations. juveniles from nine strain combinations were produced using single-pair matings. Results after 15 weeks of grow-out in hapas showed that growth performance of the Hawaiian strain was best among the purebred strains and that certain Cross combinations grew significantly faster than purebred strains. Mean body weights of specific Cross combinations with Dong Nai or Mekong as dams and the introduced strain (Hawaiian) as sires were significantly heavier than those of Purebred Dong Nai or Mekong strains. While males reached heavier mean weights than females. male variation among the strains was obscured by social factors that produced different frequencies of male morphotypes (blue claw, orange claw and small males). Results suggest presence of potentially Valuable heterosis and possible impact of the direction of Cross. From a practical Viewpoint this Could be exploited upon by either, including different forms of Crossbreeding, or alternatively, by creating a composite Population for future selection. Potential problems and challenges encountered during the trials are discussed. (c) 2008 Elsevier B.V. All rights reserved.

Raul W Ponzoni - One of the best experts on this subject based on the ideXlab platform.

  • genetic evaluation of a complete Diallel Cross involving three populations of freshwater prawn macrobrachium rosenbergii from different geographical regions of india
    Aquaculture, 2011
    Co-Authors: Bindu R Pillai, Nguyen Hong Nguyen, Raul W Ponzoni, Kanta Das Mahapatra, Lopamudra Sahoo, P L Lalrinsanga, S Mohanty, Swagathika Sahu, Sovan Sahu, Hooi Ling Khaw
    Abstract:

    Abstract Estimates of additive genetic, reciprocal and average heterosis effects were obtained from a three by three complete Diallel Cross experiment for giant freshwater prawn Macrobrachium rosenbergii . The data were generated in two batches. Three populations were sampled from the states of Gujarat (West), Kerala (South West) and Orissa (East) in India. The two mating batches of Diallel Crosses were combined in the analysis. A total 4773 animals (2233 in Batch 1 and 2540 in Batch 2) were tagged with VIA (Visible Implant Alpha numeric tags). A total of 2545 animals (979 and 1566 from Batch 1 and 2, respectively) were harvested with readable VIA tags and were; therefore available for analysis. The fixed effects included in the models were test environment (ponds 1 or 2 in batch 1, ponds 3 or 4 in batch 2), sex (male or female) and batch (1 or 2). Age at harvest was fitted as linear covariate. The genotype effect was partitioned into additive, non additive and reciprocal Cross effects. Body weight, standard length and carapace length were recorded during tagging, sampling and harvesting. Estimates of additive genetic effect in the three stocks showed that the Kerala stock had greater body weight, carapace length and standard length, followed by Orissa then Gujarat. Average heterosis for body traits was low (3.1 to 6.3%) and not significantly different from zero. The results are discussed with respect to the choice of the most appropriate breeding strategy to improve the performance of M. rosenbergii in India.

  • estimates of strain additive and non additive genetic effects for growth traits in a Diallel Cross of three strains of giant freshwater prawn macrobrachium rosenbergii in vietnam
    Aquaculture, 2010
    Co-Authors: Nguyen Minh Thanh, Nguyen Hong Nguyen, Raul W Ponzoni, Nguyen Thanh Vu, Andrew C Barnes, Peter B Mather
    Abstract:

    Abstract Additive genetic, heterotic and strain reciprocal effects were estimated using a Diallel Cross of two local wild strains of the giant freshwater prawn ( Macrobrachium rosenbergii ) in Vietnam (Dong Nai and Mekong) and a third domesticated Hawaiian strain, newly introduced to Vietnam. While some minor heterotic outcomes were detected in specific Crosses, strain additive genetic and reciprocal effects were more significant sources of variation for all growth traits measured. Strain additive genetic effects were highest for the Hawaiian strain (+ 10.2%) and lowest for the Mekong strain (− 11.6%) for harvest body weight. A similar pattern of strain additive genetic effects was observed for carapace and standard length. Average heterotic outcomes for all growth traits were small and not significantly different from zero ( P  > 0.05), and ranged from + 0.7 for carapace length to + 1.5% for body weight. The reciprocal effect had a positive effect on growth rate, because Crosses between the Dong Nai (D) or Mekong (M) strains as dam and the Hawaiian (H) strain as sire grew faster than did their reciprocal Crosses (HD and HM). The relative high correlation between strain additive performance and total performance for all traits ( r  = 0.71 to 0.77) suggests potential for exploiting strain additive variation to improve M. rosenbergii culture stock via direct selection among strains. A breeding strategy for genetic improvement of giant freshwater prawn in Vietnam is discussed.

  • evaluation of growth performance in a Diallel Cross of three strains of giant freshwater prawn macrobrachium rosenbergii in vietnam
    Aquaculture, 2009
    Co-Authors: Nguyen Minh Thanh, Nguyen Hong Nguyen, Raul W Ponzoni, Andrew J Barnes, Peter B Mather
    Abstract:

    The giant freshwater prawn (Macrobrachium rosenbergii) is one of the most important crustacean species produced in inland aquaculture in many tropical and subtropical countries worldwide. The aim of the current study was to evaluate the growth performance of three strains of giant freshwater prawn that originated from geographically separated locations in a complete (3x3) Diallel Cross as a starting point for a stock improvement program for the industry in Vietnam. Crosses were established over two generations using two wild Vietnamese river populations (Dong Nai and Mekong) domesticated for the study and an introduced Hawaiian strain that had been in Culture for many generations. juveniles from nine strain combinations were produced using single-pair matings. Results after 15 weeks of grow-out in hapas showed that growth performance of the Hawaiian strain was best among the purebred strains and that certain Cross combinations grew significantly faster than purebred strains. Mean body weights of specific Cross combinations with Dong Nai or Mekong as dams and the introduced strain (Hawaiian) as sires were significantly heavier than those of Purebred Dong Nai or Mekong strains. While males reached heavier mean weights than females. male variation among the strains was obscured by social factors that produced different frequencies of male morphotypes (blue claw, orange claw and small males). Results suggest presence of potentially Valuable heterosis and possible impact of the direction of Cross. From a practical Viewpoint this Could be exploited upon by either, including different forms of Crossbreeding, or alternatively, by creating a composite Population for future selection. Potential problems and challenges encountered during the trials are discussed. (c) 2008 Elsevier B.V. All rights reserved.

Nguyen Minh Thanh - One of the best experts on this subject based on the ideXlab platform.

  • estimates of strain additive and non additive genetic effects for growth traits in a Diallel Cross of three strains of giant freshwater prawn macrobrachium rosenbergii in vietnam
    Aquaculture, 2010
    Co-Authors: Nguyen Minh Thanh, Nguyen Hong Nguyen, Raul W Ponzoni, Nguyen Thanh Vu, Andrew C Barnes, Peter B Mather
    Abstract:

    Abstract Additive genetic, heterotic and strain reciprocal effects were estimated using a Diallel Cross of two local wild strains of the giant freshwater prawn ( Macrobrachium rosenbergii ) in Vietnam (Dong Nai and Mekong) and a third domesticated Hawaiian strain, newly introduced to Vietnam. While some minor heterotic outcomes were detected in specific Crosses, strain additive genetic and reciprocal effects were more significant sources of variation for all growth traits measured. Strain additive genetic effects were highest for the Hawaiian strain (+ 10.2%) and lowest for the Mekong strain (− 11.6%) for harvest body weight. A similar pattern of strain additive genetic effects was observed for carapace and standard length. Average heterotic outcomes for all growth traits were small and not significantly different from zero ( P  > 0.05), and ranged from + 0.7 for carapace length to + 1.5% for body weight. The reciprocal effect had a positive effect on growth rate, because Crosses between the Dong Nai (D) or Mekong (M) strains as dam and the Hawaiian (H) strain as sire grew faster than did their reciprocal Crosses (HD and HM). The relative high correlation between strain additive performance and total performance for all traits ( r  = 0.71 to 0.77) suggests potential for exploiting strain additive variation to improve M. rosenbergii culture stock via direct selection among strains. A breeding strategy for genetic improvement of giant freshwater prawn in Vietnam is discussed.

  • evaluation of growth performance in a Diallel Cross of three strains of giant freshwater prawn macrobrachium rosenbergii in vietnam
    Aquaculture, 2009
    Co-Authors: Nguyen Minh Thanh, Nguyen Hong Nguyen, Raul W Ponzoni, Andrew J Barnes, Peter B Mather
    Abstract:

    The giant freshwater prawn (Macrobrachium rosenbergii) is one of the most important crustacean species produced in inland aquaculture in many tropical and subtropical countries worldwide. The aim of the current study was to evaluate the growth performance of three strains of giant freshwater prawn that originated from geographically separated locations in a complete (3x3) Diallel Cross as a starting point for a stock improvement program for the industry in Vietnam. Crosses were established over two generations using two wild Vietnamese river populations (Dong Nai and Mekong) domesticated for the study and an introduced Hawaiian strain that had been in Culture for many generations. juveniles from nine strain combinations were produced using single-pair matings. Results after 15 weeks of grow-out in hapas showed that growth performance of the Hawaiian strain was best among the purebred strains and that certain Cross combinations grew significantly faster than purebred strains. Mean body weights of specific Cross combinations with Dong Nai or Mekong as dams and the introduced strain (Hawaiian) as sires were significantly heavier than those of Purebred Dong Nai or Mekong strains. While males reached heavier mean weights than females. male variation among the strains was obscured by social factors that produced different frequencies of male morphotypes (blue claw, orange claw and small males). Results suggest presence of potentially Valuable heterosis and possible impact of the direction of Cross. From a practical Viewpoint this Could be exploited upon by either, including different forms of Crossbreeding, or alternatively, by creating a composite Population for future selection. Potential problems and challenges encountered during the trials are discussed. (c) 2008 Elsevier B.V. All rights reserved.

Bjarne Gjerde - One of the best experts on this subject based on the ideXlab platform.

  • estimates of strain additive genetic heterosis and reciprocal effects for male proportion in nile tilapia oreochromis niloticus l
    Aquaculture, 2011
    Co-Authors: Carlos Lozano, Hans B Bentsen, Edna E Dionisio, Bjarne Gjerde, Morten Rye
    Abstract:

    Abstract Data from the GIFT complete Diallel Cross with eight strains of Nile tilapia reared at seven different grow out environments were analyzed to evaluate the feasibility of using breeders from the best performing strains or strain combinations to increase male proportion in the population. Of the three strain genetic by test environment interaction effects evaluated, i.e., strain additive, strain reciprocal and strain heterosis, only the latter was found to be significantly different from zero ( P P P P P P  > 0.05), however for some strain Crosses the total strain heterosis effect was substantial with 19.7 ± 4.4 percentage points ( P

  • genetic evaluation of four strains of oreochromis shiranus for harvest body weight in a Diallel Cross
    Aquaculture, 2006
    Co-Authors: Alfred Ochanza Maluwa, Bjarne Gjerde
    Abstract:

    Abstract Estimates of strain additive genetic, total heterosis and general reciprocal effects were obtained from a complete Diallel Cross with four strains (Shire, Nkhotakota, Chilwa and Chiuta) of Oreochromis shiranus in Malawi. Growth was recorded at harvest on 367 individually tagged progeny from 16 strain combinations after a grow-out period of 180 days aCross three test environments that represented different agro-climatic zones of the country. Each of the 16 strain combinations was produced from 3 to 5 five single-pair matings; i.e., 6–10 parents per strain combination. In total, the number of contributing sires per strain ranged from 14 to 16 and the number of contributing dams also from 14 to16. ACross the test environments, the mean body weight was 75 g and the males had a significantly higher body weight at harvest than the females (23%; P P  > 0.05) meaning that with respect to the harvest body weight trait, there is no need to develop specific strains for the different agro-climatic conditions of the country. The strain total heterosis effect accounted for 15.3% ( P P P  > 0.05) effects. For the strain additive genetic effect, Shire was the best and Chiuta the poorest strain, performing 16.9% above and 10.3% below the mean of the purebred strains, respectively. Five out of the six strain Crosses showed a significant positive total heterosis effect ranging from 12.3% to 17.0% above the mean body weight of the purebred strains. The average heterosis effect was 12.5%. The correlation between the strain additive genetic and the strain additive genetic plus total heterosis performance of the six strain Crosses was low ( r  = 0.25). The results show that for harvest body weight there are substantial additive genetic and total heterosis differences among pure and Crossbred strains of O. shiranus . The exploitation of these genetic differences in a breeding program is discussed.