Mass selection for survival and resistance to OsHV-1 infection in Crassostrea gigas spat in field conditions: response to selection after four generations
Mass selection for survival and resistance to OsHV-1 infection in Crassostrea gigas spat in field conditions: response to selection after four generations
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DOI：
10.1016/j.aquaculture.2015.04.029
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发表时间：
2015-09-01
期刊：
影响因子：
4.5
通讯作者：
Maurouard, Elise
中科院分区：
文献类型：
--
作者：
Degremont, Lionel;Nourry, Max;Maurouard, Elise
牡蛎疱疹病毒1型（ostreid herpesvirus 1，OsHV-1）是影响太平洋牡蛎（Crassostrea gigas）的主要病原之一，在世界范围内发生过多次死亡事件。我们报告了我们的实验育种计划的第一个结果，使用集中在生存和抵抗OsHV-1四代选择后，两个线。这些品系来源于2008年从Marennes-Oleron湾采样的两种成年野生牡蛎。每一个品系都在2009年2月产卵，以产生基础种群。然后，这两条线路要么受到OsHV-1的保护，要么在2009年进行实地测试，暴露于OsHV-1。在2010年至2013年期间，对于每个品系，使用上一代的幸存者作为选择组或使用保护免于OsHV-1的牡蛎作为对照组，每年生产一代。经过一个世代的选择（G（1）），选择组的平均存活率为34.5%，而对照组为12.3%。第四代选择（G（4）），选择组的存活率达到69.0%，对照组的存活率为7.3%。选择的C. G1、G2、G3和G4代的平均产卵量分别比对照增加22.2%、43.9%、50.2%和61.8%。我们的研究表明，在四代选择后，存活和OsHV-1抗性的混合选择是成功的，从而表明所选性状的显着遗传改良。在G（4）中观察到基因型x大小的相互作用，当选择的幼鱼以1 g转移时，存活率为55.1%，而当它们以3 g转移时，存活率为89.9%。我们的研究是第一个提供一些估计的实现遗传抗病性使用质量选择方案在牡蛎物种的值范围从0.34到0.63取决于暴露于OsHV-1的牡蛎的大小。在G4中选择对OsHV-1感染具有较高抗性的牡蛎显示出较高的生长（58.4 mm - 19.4 g）比对照（51.4 mm - 15.2 g）高，并且混合选择使所选牡蛎的产量（13.3 kg）比对照（1.2 kg）显著提高。商业孵化场不能负担基于家系的选择，因为基于家系的选择需要为基础群体生产许多家系。千兆。(C)2015 Elsevier B. V.版权所有。
The ostreid herpesvirus 1 (OsHV-1) is one of the major pathogens affecting the Pacific oyster Crassostrea gigas, and numerous mortality outbreaks have been observed worldwide. We report the first results of our experimental breeding program using mass selection focused on survival and resistance to OsHV-1 after four generations of selection for two lines. These lines originated from two stocks of adult wild oysters sampled from the Marennes-Oleron Bay in 2008. Each line was spawned in February 2009 to produce the base populations. Both lines were then either protected from OsHV-1 or tested in the field in 2009 where they were exposed to OsHV-1. For each line during 2010 to 2013, one generation per year was produced using either the survivors of the previous generation for the selected group or the oysters protected from OsHV-1 for the control group. After one generation of selection (G(1)) for both lines, the mean survival of the selected group was 34.5% compared with 12.3% in the control group. For the fourth generation of selection (G(4)), the survival of the selected group reached 69.0% and the survival of the control group was 7.3%. The gain in survival of the selected C. gigas spat over the control increased by 22.2%, 43.9%, 50.2% and 61.8% for the G(1), G(2), G(3) and G(4) generations, respectively. Our study demonstrates that mass selection for survival and OsHV-1 resistance was successful after four generations of selection, thus indicating a significant genetic improvement for the selected trait. A genotype x size interaction was observed with 55.1% of survival in G(4) when selected spat were transferred at 1 g versus 89.9% of survival when they were transferred at 3 g. Our study is the first to provide some estimates of the realized heritability for disease resistance using a mass selection scheme in an oyster species with values ranging from 0.34 to 0.63 depending on the size of the oysters exposed to OsHV-1. Oysters selected for their higher resistance to OsHV-1 infection in G4 showed higher growth (58.4 mm - 19.4 g) than controls (51.4 mm - 15.2 g), and mass selection had significantly improved the yield for the selected oysters (13.3 kg) over the controls (1.2 kg). Mass selection could be easily implemented by a commercial hatchery that cannot afford family-based selection that requires the production of numerous families for the base population.Statement of relevanceStrong impact on breeding program working on OsHV-1 resistance in C. gigas. (C) 2015 Elsevier B.V. All rights reserved.