Vu Nguyen Thanh, Trong Trinh Quoc, Nguyen Nguyen Hong
National Breeding Centre for Southern Freshwater Aquaculture, Research Institute for Aquaculture No. 2, 116 Nguyen Dinh Chieu Street, District 1, HCM City, Vietnam.
Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, QLD, 4558, Australia.
BMC Genet. 2017 Jun 21;18(1):56. doi: 10.1186/s12863-017-0521-7.
Correlated genetic response in survival to selection for high growth has not been reported in giant freshwater prawn (GFP) (Macrobrachium rosenbergii). The main aim of this study was to measure genetic changes and estimate heritability for this character (survival rate) and its genetic associations with body traits in a GFP population selected over eight generations from 2008 to 2015. Statistical analyses were conducted on 106,696 data records, using threshold logistic mixed model.
The estimated heritability for survival was 0.14 ± 0.04 and significant. Genetic associations of survival with body traits (weight, length and width) were weak, with the estimates of genetic correlations between the traits close to zero. Realised genetic changes in survival, calculated as the difference in estimated breeding values between the selection line and control group within the same generation, was in positive direction but the estimates were not significantly different from zero regardless of the expression unit used either in actual unit of measurement or genetic standard deviation unit. On the other hand, communal testing of stocks in the latest generation, namely G7 (2015), showed that the selection line had 18% higher survival rate than progeny of the wild prawns originated from Mekong river. This result suggests that inadvertent changes in survival occurred during domestication-selection.
It is concluded that selection for high growth had no significant effect on survival in the present population of M. rosenbergii.
在罗氏沼虾中，尚未有关于高生长选择下生存相关遗传反应的报道。本研究的主要目的是测量2008年至2015年经过八代选育的罗氏沼虾群体中该性状（存活率）的遗传变化，估计其遗传力，并评估其与体型性状的遗传关联。使用阈值逻辑混合模型对106,696条数据记录进行了统计分析。
估计的存活率遗传力为0.14±0.04，具有显著性。存活率与体型性状（体重、体长和体宽）的遗传关联较弱，性状间遗传相关估计值接近零。以同一代中选择系和对照组估计育种值的差异计算得出的存活率实际遗传变化呈正向，但无论使用实际测量单位还是遗传标准差单位作为表达单位，估计值与零均无显著差异。另一方面，对最新一代（即G7，2015年）的群体进行共同测试表明，选择系的存活率比源自湄公河的野生虾后代高18%。这一结果表明，在驯化选择过程中存活率发生了意外变化。
得出结论，在当前罗氏沼虾群体中，高生长选择对存活率没有显著影响。
